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Archive for the ‘Natural sciences’ Category

More complicated than you think

Biodiversity

A new, giant virus is confounding old certainties

BIODIVERSITY is not just a matter of tigers and whales, or butterflies and trees, or even coral reefs and tuna. It is also about myriad creatures too small to see that live in numbers too large to count in ways too numerous to imagine. It is easy to forget, especially at meetings like the one to discuss the Convention on Biological Diversity that has been taking place in Nagoya under the auspices of the United Nations, that most of biology is in fact microscopic. Indeed, the more microscopic biology gets, the more diverse it becomes.

In that context, the discovery by Curtis Suttle of the University of British Columbia and his colleagues of a critter they propose to call Cafeteria roenbergensis virus, or CroV, should not be surprising. But for those brought up on a textbook definition of what a virus is, it is still a bit of a shock. For CroV is not a very viruslike virus. It has 544 genes, compared with the dozen or so that most viruses sport. And it may be able to make its own proteins—a task that viruses usually delegate to the molecular machinery of the cells they infect.

CroV, as its full name suggests, is a parasite of Cafeteria roenbergensis, a single-celled planktonic organism that was itself discovered only in 1988. Despite the recentness of its discovery, C. roenbergensis is one of the commonest creatures on the planet. It is also reckoned by some, given that it hunts down and eats bacteria, to be the most abundant predator on Earth. It is found in every ocean. The samples of C. roenbergensis from which Dr Suttle and his team extracted their quarry were collected off the coast of Texas.

To see a world in a grain of sand

That quarry’s nature, reported this week in the Proceedings of the National Academy of Sciences, is not a complete surprise. A larger virus, called Mimivirus, which lives in freshwater amoebas, turned up in 2003 and a few other, similar, viruses have been found since then. But CroV is by far the biggest to come out of the sea.

Those who like their categories cut and dried may wonder whether viruses are alive or not. Wise biologists do not struggle too much with such questions. Viruses have genes, can reproduce and are subject to the evolutionary pressures imposed by natural selection. That is enough for biology to claim them. As for CroV, those 544 genes (composed of 730,000 base pairs, the DNA letters in which the language of the genes is written) mean its genome is bigger than those of several bacteria—creatures which everyone agrees are alive.

The problem with categorical thinking in biology is that evolution does not work like that. It actually works by whatever works working. If an organism can successfully subcontract part of the business of metabolism to another while retaining the rest itself, rather than offloading the whole lot as most viruses do, then there are no rules to stop it happening.

CroV seems to do just that. Besides the genes that relate to protein synthesis it has others which encode DNA repair mechanisms and still others which are involved with protein recycling and signalling within cells. This is not mere hijacking. It is tantamount to a complete personality transplant for the infected cell.

About a third of CroV’s genes are similar to Mimivirus genes, suggesting they share a distant ancestor. On the other hand, two-thirds are not. A significant chunk of them seem to have been copied from bacteria. But the majority are unique, and previously unknown to science. A whole new chapter of life, in other words, has been opened.

This discovery, then—and the earlier one of C. roenbergensis itself—speak volumes, albeit in a microscopic language, about biodiversity. Two centuries after Carl Linnaeus invented the system now used to describe it, and a century after Charles Darwin worked out what causes it, the ability of that diversity to surprise is still staggering.

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Full article and photo: http://www.economist.com/node/17358573

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To Know a Fly

By Vincent G. Dethier (1962)

Vincent Dethier spent a lifetime researching the senses, in particular those of insects. His “To Know a Fly” (not an easy task—there are more than 50,000 species) is an exuberant investigation of such matters as taste, hunger and satiation and their role in the survival of the humble housefly. He observes that a pregnant female fly will stop consuming sugar—an “adequate food for her, but useless for her eggs,” preferring instead protein that is good for the eggs but won’t nourish her. “In some quarters it would be hailed as maternal instinct,” he writes, “and by so naming it we would be no nearer an understanding of what it is.” Dethier’s learning from countless fly experiments is vast, but he is bracing in his acknowledgment of what remains unknown. “To espouse ultimate understanding of even so simple a brain,” he says, “reflects an optimism outside the natural order.” But he is entirely convincing when he says that a properly conducted experiment is “an adventure, an expedition, a conquest” and that to know a fly “is to share a bit in the sublimity of Knowledge.”

Nerve Cells and Insect Behavior

By Kenneth D. Roeder (1963)

This book presents Kenneth Roeder’s most famous discovery—that some moths are able to detect the calls of echo-locating bats and employ defensive measures to evade the predators. The revelation was made all the more remarkable by its timing: only a few years after Donald Griffin astonished the scientific community in 1958 with his revelation that bats “see” the world with their ears. Roeder examines the senses and behavior of insects at the level of neural mechanisms, and along the way we learn about not only the tactics of escape-artist moths but also about the evasive maneuvers of cockroaches and other insects. The study is the product of neuron monitoring via electrical eavesdropping, which means that there is a lot of technical writing in “Nerve Cells and Insect Behavior”—a fascinating work if you stay with it.

Desert Animals

By Knut Schmidt-Nielsen (1964)

Despite extremes of heat and lack of water, the desert is home to “a richer animal life than we can imagine,” Knut Schmidt-Nielsen says in this pioneering study. The animals that survive in such extreme conditions are aided by a variety of adaptations. For instance, the camel’s body temperature fluctuates wildly—camels start out “cold” in the morning so that they overheat less easily later in the day. The kangaroo rat’s kidney produces only small amounts of highly concentrated urine, enabling the animal to forgo water for long periods and live on air-dried food. After reading Schmidt-Nielsen’s evocation of a world where countless hardy animals thrive, you’ll never again look at a desert expanse and think it barren.

Honeybee Democracy

By Thomas D. Seeley (2010)

In ‘HONEYBEE DEMOCRACY,’ Thomas Seeley explains how a honeybee colony divides and reproduces: A contingent of 10,000 bees or more communicate among themselves and arrive unanimously at a decision about the best available new home. Building on a lifetime of observation and experimentation, Seeley relates the story with admirable clarity as we see his beloved honeybees—which have been in the consensus-building business for perhaps 200 million years—embark on the establishment of a new outpost. The process begins with a few scout bees and involves a vigorous debate before an agreement is reached. Then, on a signal, the group leaves en masse for the chosen place, likely a hollow tree some kilometers distant that the majority of the bees have never seen before. This spirit of cooperation, Seeley says, has much to tell us about solving complex human problems.

The Beak of the Finch

By Jonathan Weiner (1994)

Darwin made the Galápagos finches famous, but biologists Peter and Rosemary Grant and their graduate students deepened our understanding of how these small birds have survived and adapted across the centuries. Darwin supposed that the various kinds of finches, with their varying beaks and body sizes, came from diverse genetic backgrounds. But he later concluded that the finches were closely related and had thus likely evolved from a common stock. The Grants—working for three decades on the islands—bolstered Darwin’s insight that species are not immutable, as had been thought. One potential problem with Darwin’s theory had been that species appeared to be largely static, but the Grants succeeded in showing that evolution can be very rapid—beak shapes could change from year to year in response to, say, heightened mortality rates caused by food scarcity. Evidence of speedy adaptation has added meaning today as we witness insects becoming resistant to insecticides and bacteria surviving despite the most potent antibiotics.

Mr. Heinrich is the author of “The Nesting Season: Cuckoos, Cuckolds, and the Invention of Monogamy.”

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Full article and photo: http://online.wsj.com/article/SB10001424052702304510704575562250721139246.html

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NO RIBS? An anatomical quirk may tell why sloths have up to 10 vertebrae.

It is not quite how the elephant’s child got his long nose, but still it is research worthy of Rudyard Kipling: scientists said Monday that they have figured out how sloths got their long necks.

Throughout the animal kingdom, most mammalian creatures, from mice to giraffe, have a seven-vertebrae neck.

Sloths, however, are a puzzling exception. They can have as many as 10 vertebrae, posing one of the enduring enigmas for scientists, who have long wondered what explains the anatomical quirk.

Scientists at the University of Cambridge in England said they now think they have the answer.

After analyzing the development of the vertebral column in sloths they made a startling discovery: the part of the skeleton which they had long believed to be part of the sloth rib cage is, in fact, analogous to the bottom of the mammal’s “neck.”

In other words, the bottom neck vertebrae of sloths show a similar sequence of development as the top rib cage vertebrae of other mammals, both of which start at eight vertebrae down from the head.

The research, published Monday in the journal The Proceedings of the National Academy of Sciences, showed that the bottom “neck” vertebrae of sloths are developmentally the same as rib cage vertebrae of other mammals — just without ribs.

“Even though they’ve got eight to 10 ribless vertebrae above the shoulders, unlike the seven of giraffes, humans, and nearly every other species of mammal, those extra few are actually rib cage vertebrae masquerading as neck vertebrae,” said Robert Asher, of the zoology department at Cambridge.

By observing the position of bone formation within the vertebral column, they determined that all mammals, including sloths, are similar in when they develop the eighth vertebra down from the head — whether or not it is actually part of the neck.

The unusual anatomy has to do with how the sloth evolved millions of years ago, in contrast to other mammals.

The Cambridge researchers said the new results support the interpretation that the limb girdles and at least part of the rib cage derive from different embryonic tissues than the vertebrae, and that during the course of evolution, they have moved in concert with each other relative to the vertebral column.

In sloths, the position of the shoulders, pelvis, and rib cage are linked with one another, and compared to their common ancestor shared with other mammals, have shifted down the vertebral column to make the neck longer, the researchers said.

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Full article and photo: http://www.nytimes.com/2010/10/19/science/19sloth.html?_r=1&ref=science

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NO ANT EGGS OF THEIR OWN Dr. William Hamilton believed that helping your relatives could spread your genes faster

Why are worker ants sterile? Why do birds sometimes help their parents raise more chicks, instead of having chicks of their own? Why do bacteria explode with toxins to kill rival colonies? In 1964, the British biologist William Hamilton published a landmark paper to answer these kinds of questions. Sometimes, he argued, helping your relatives can spread your genes faster than having children of your own.

For the past 46 years, biologists have used Dr. Hamilton’s theory to make sense of how animal societies evolve. They’ve even applied it to the evolution of our own species. But in the latest issue of the journal Nature, a team of prominent evolutionary biologists at Harvard try to demolish the theory.

The scientists argue that studies on animals since Dr. Hamilton’s day have failed to support it. The scientists write that a close look at the underlying math reveals that Dr. Hamilton’s theory is superfluous. “It’s precisely like an ancient epicycle in the solar system,” said Martin Nowak, a co-author of the paper with Edward O. Wilson and Corina Tarnita. “The world is much simpler without it.”

Other biologists are sharply divided about the paper. Some praise it for challenging a concept that has outlived its usefulness. But others dismiss it as fundamentally wrong.

“Things are just bouncing around right now like a box full of Ping-Pong balls,” said James Hunt, a biologist at North Carolina State University.

Dr. Hamilton, who died in 2000, saw his theory as following logically from what biologists already knew about natural selection. Some individuals have more offspring than others, thanks to the particular versions of genes they carry. But Dr. Hamilton argued that in order to judge the reproductive success of an individual, scientists had to look at the genes it shared with its relatives.

We inherit half of our genetic material from each parent, which means that siblings have, on average, 50 percent of the same versions of genes. We share a lower percentage with first cousins, second cousins and so on. If we give enough help to relatives so they can survive and have children, then they can pass on more copies of our own genes. Dr. Hamilton called this new way of tallying reproductive success inclusive fitness.

Each organism faces a trade-off between putting effort into raising its own offspring or helping its relatives. If the benefits of helping a relative outweigh the costs, Dr. Hamilton argued, altruism can evolve.

Dr. Hamilton believed that one of the things his theory could explain was the presence of sterile females among ants, wasps, and some other social insects. These species have peculiar genetics that cause females to be more closely related to their sisters than to their brothers, or even to their own offspring. In these situations, a female ant may be able to spread more genes by helping to raise her queen mother’s eggs than trying to lay eggs of her own.

But as the years passed, Dr. Wilson’s enthusiasm for the theory waned. “It was getting tattered,” he said. Many species with sterile females, for example, do not have the strange genetics of ants and wasps. And many species with the right genetics have not produced sterile females.

After reading a 2008 article in which Dr. Wilson aired his misgivings, Dr. Nowak got in touch with him. Dr. Nowak and Dr. Tarnita were studying the mathematical underpinnings of evolution. They wanted to carry out a mathematical analysis of natural selection in general and inclusive fitness in particular. Dr. Wilson joined them.

The scientists developed equations that described two different behaviors in a population. One strategy might be selfish and the other altruistic — leaving their nest after they hatch versus staying to help rear young, for example. The scientists then calculated the conditions in which one strategy or the other takes over the whole population.

The researchers found that inclusive fitness theory worked only under special conditions. All the effects that the animals had on each other had to take place on a one-to-one basis. In the real world, individuals may benefit from many other individuals as a group.

Standard natural selection, the scientists argue, explains everything inclusive fitness theory was supposed to, without these special conditions.

Dr. Nowak and his colleagues argue that their analysis should free scientists to think of other ways that altruism and other kinds of social behavior might evolve.

Thinking about why a worker would sacrifice her own offspring turns out be the wrong perspective on the question, they argue. Instead, they say, we should put ourselves in the queen’s perspective. They offer a mathematical model suggesting how natural selection could produce offspring that stay at a queen’s nest. If she produces daughters that stay in the nest, she can spend more time laying eggs, rather than hunting for food to feed her young.

“I think they’ve done a very thorough job,” said Michael Doebeli of the University of British Columbia. He has also grown skeptical about the importance many colleagues have put on inclusive fitness in recent years. “The people who swear by this method somehow think there’s something magic about it that explains everything,” he said.

Dr. Hunt, who studies social wasps, does not find Dr. Hamilton’s ideas useful because it is nearly impossible to calculate the costs and benefits of helping relatives.

“I have never felt that inclusive fitness has contributed to an understanding of what’s going on,” he said. The Harvard team, Dr. Hunt said, is “basically on target.”

A number of scientists strongly disagree, though. “This paper, far from showing shortcomings in inclusive fitness theory, shows the shortcomings of the authors,” said Frances Ratnieks of the University of Sussex.

Dr. Ratnieks argues that the Harvard researchers cannot rule out kinship as a driving force in social evolution because their model is flawed. It does not include how closely related animals are.

It would be as if a team of researchers carried out a study on the effects of diet and exercise on health. Their subjects get different amounts of exercise but stay on the same diet. In the end, the experiment might show that exercise makes people more healthy. But it would not make any sense to also conclude that diet plays no role.

“If you don’t vary something you cannot say how important it is,” said Dr. Ratnieks.

Andy Gardner, an evolutionary biologist at Oxford, said bluntly, “This is a really terrible article.” One problem Dr. Gardner points to is the Harvard team’s claim that the past 40 years of research on inclusive fitness has yielded nothing but “hypothetical explanations.”

“This claim is just patently wrong,” Dr. Gardner said. He points to the question of how many sons and daughters mothers produce among the many insights inclusive fitness has brought.

In most species, the balance is 50-50. But there are exceptions. In some ant species, for example, the ratio is around three daughters for every son. That is because the sterile female workers invest more into female larvae than males. Inclusive fitness theory predicts just this situation, since the workers are more closely related to their sisters than to their brothers.

Dr. Gardner and a number of other biologists have co-authored a reply that they will be sending to Nature to challenge the new paper.

Dr. Hunt hopes to move the debate toward a resolution with a meeting he is to run in October at the National Evolutionary Synthesis Center in Durham, N.C. He will be bringing together scientists who build models of all the potential factors that drive the evolution of societies, from their kinship to their ecology. Ultimately, the scientists hope to build a model that can take into account all of these factors at once. “They’re all stoked, and I am too,” Dr. Hunt said.

Carl Zimmer, New York Times

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Full article and photo: http://www.nytimes.com/2010/08/31/science/31social.html

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THE ICK FACTOR The lab of Stephen A. Kells, a University of Minnesota entomologist. Bedbugs are not known to transmit disease.

Don’t be too quick to dismiss the common bedbug as merely a pestiferous six-legged blood-sucker.

Think of it, rather, as Cimex lectularius, international arthropod of mystery.

In comparison to other insects that bite man, or even only walk across man’s food, nibble man’s crops or bite man’s farm animals, very little is known about the creature whose Latin name means — go figure — “bug of the bed.” Only a handful of entomologists specialize in it, and until recently it has been low on the government’s research agenda because it does not transmit disease. Most study grants come from the pesticide industry and ask only one question: What kills it?

But now that it’s The Bug That Ate New York, Not to Mention Other Shocked American Cities, that may change.

This month, the Environmental Protection Agency and the Centers for Disease Control and Prevention issued a joint statement on bedbug control. It was not, however, a declaration of war nor a plan of action. It was an acknowledgment that the problem is big, a reminder that federal agencies mostly give advice, plus some advice: try a mix of vacuuming, crevice-sealing, heat and chemicals to kill the things.

It also noted, twice, that bedbug research “has been very limited over the past several decades.”

Ask any expert why the bugs disappeared for 40 years, why they came roaring back in the late 1990s, even why they do not spread disease, and you hear one answer: “Good question.”

“The first time I saw one that wasn’t dated 1957 and mounted on a microscope slide was in 2001,” said Dini M. Miller, a Virginia Tech cockroach expert who has added bedbugs to her repertoire.

The bugs have probably been biting our ancestors since they moved from trees to caves. The bugs are “nest parasites” that fed on bats and cave birds like swallows before man moved in.

That makes their disease-free status even more baffling.

(The bites itch, and can cause anaphylactic shock in rare cases, and dust containing feces and molted shells has triggered asthma attacks, but these are all allergic reactions, not disease.)

Bats are sources of rabies, Ebola, SARS and Nipah virus. And other biting bugs are disease carriers — mosquitoes for malaria and West Nile, ticks for Lyme and babesiosis, lice for typhus, fleas for plague, tsetse flies for sleeping sickness, kissing bugs for Chagas. Even nonbiting bugs like houseflies and cockroaches transmit disease by carrying bacteria on their feet or in their feces or vomit.

But bedbugs, despite the ick factor, are clean.

Actually it is safer to say that no one has proved they aren’t, said Jerome Goddard, a Mississippi State entomologist.

But not for lack of trying. South African researchers have fed them blood with the AIDS virus, but the virus died. They have shown that bugs can retain hepatitis B virus for weeks, but when they bite chimpanzees, the infection does not take. Brazilian researchers have come closest, getting bedbugs to transfer the Chagas parasite from a wild mouse to lab mice.

“Someday, somebody may come along with a better experiment,” Dr. Goddard said.

That lingering uncertainty has led to one change in lab practice. The classic bedbug strain that all newly caught bugs are compared against is a colony originally from Fort Dix, N.J., that a researcher kept alive for 30 years by letting it feed on him.

But Stephen A. Kells, a University of Minnesota entomologist, said he “prefers not to play with that risk.”

He feeds his bugs expired blood-bank blood through parafilm, which he describes as “waxy Saran Wrap.”

Coby Schal of North Carolina State said he formerly used condoms filled with rabbit blood, but switched to parafilm because his condom budget raised eyebrows with university auditors.

Why the bugs disappeared for so long and exploded so fast after they reappeared is another question. The conventional answer — that DDT was banned — is inadequate. After all, mosquitoes, roaches and other insects rebounded long ago.

Much has to do with the bugs’ habits. Before central heating arrived in the early 1900s, they died back in winter. People who frequently restuffed their mattresses or dismantled their beds to pour on boiling water — easier for those with servants — suffered less, said the bedbug historian Michael F. Potter of the University of Kentucky.

Early remedies were risky: igniting gunpowder on mattresses or soaking them with gasoline, fumigating buildings with burning sulfur or cyanide gas. (The best-known brand was Zyklon B, which later became infamous at Auschwitz.)

Success finally arrived in the 1950s as the bugs were hit first with DDT and then with malathion, diazinon, lindane, chlordane and dichlorovos, as resistance to each developed. In those days, mattresses were sprayed, DDT dust was sprinkled into the sheets, nurseries were lined with DDT-impregnated wallpaper.

In North America and Western Europe, “the slate was virtually wiped clean,” said Dr. Potter, who has surveyed pest-control experts in 43 countries. In South America, the Middle East and Africa, populations fell but never vanished.

The bugs also persisted on domestic poultry farms and in a few human habitations.

One theory is that domestic bedbugs surged after pest control companies stopped spraying for cockroaches in the 1980s and switched to poisoned baits, which bedbugs do not eat.

But the prevailing theory is that new bugs were introduced from overseas, because the ones found in cities now are resistant to different insecticides from those used on poultry or cockroaches.

Exactly where they came from is a mystery. Dr. Schal is now building a “world bedbug collection” and hopes to produce a global map of variations in their genes, which might answer the question.

Experts say they’ve heard blame pinned on many foreign ethnic groups and on historic events from the fall of the Berlin Wall to the Persian Gulf war to the spread of mosquito nets in Africa. Every theory has holes, and many are simply racist.

(For example, Dr. Potter said, he has heard Mexicans blamed, but Mexican pest control companies he contacted said they rarely see the bugs except in the homes of people returning from the United States, often with scavenged furniture.)

Pest-control companies say hotels, especially airport business hotels and resorts attracting foreign tourists, had the first outbreaks, said both Dr. Potter and Richard Cooper, a pest-control specialist.

Whatever the source, the future is grim, experts agreed.

Many pesticides don’t work, and some that do are banned — though whether people should fear the bug or the bug-killer more is open to debate.

“I’d like to take some of these groups and lock them in an apartment building full of bugs and see what they say then,” Dr. Potter said of environmentalists.

Treatment, including dismantling furniture and ripping up rugs, is expensive. Rather than actively hunting for bugs, hotels and landlords often deny having them.

Many people are not alert enough. (Both Mr. Cooper and Dr. Goddard said they routinely pull apart beds and even headboards when they check into hotels. Dr. Goddard keeps his luggage in the bathroom. Mr. Cooper heat-treats his when he gets home.)

Some people overreact, even developing delusional parasitosis, the illusion that bugs are crawling on them.

“People call me all the time, losing their minds, like it’s a curse from God,” Dr. Miller said.

The reasonable course, Dr. Goddard said, is to recognize that we are, in effect, back in the 1920s “Sleep tight, don’t let the bedbugs bite” era. People should be aware, but not panicky.

However, he added, “I don’t even know what to say about them being in theaters. That’s kind of spooky.”

Well, he was asked — can you feel them bite?

“No,” he said. “If I put them on my arm and close my eyes, I never feel them. But I once got my children to put them on my face, and I did. Maybe there are more nerve endings.”

Why in the world, he was asked, would he ask kids to do that?

“Oh, you know,” he said. “Bug people are crazy.”

Donald G. McNeil Jr., New York Times

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Full article and photo: http://www.nytimes.com/2010/08/31/science/31bedbug.html

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Life in the Third Realm

Archaea were first found in areas like Bumpass Hell in Lassen Volcanic National Park, where fissures and volcanic heat created hot springs.

It’s that time of the month again. Yes: it’s time for Life-form of the Month. In case you’ve forgotten, this coming Saturday is International Day for Biological Diversity, a day of celebrations and parties to appreciate the other occupants of the planet. So if you do nothing else this weekend, drink a toast to “Other Life-forms!” In honor of this event, my nomination for Life-form of the Month: May is a group of abundant and fascinating beings that are undeservedly obscure: the archaea.

Say who?

Archaea are single-celled microbes with a reputation for living in tough environments like salt lakes, deep sea vents or boiling acid. One strain can grow at temperatures as high as 121 degrees Celsius (249.8 degrees Fahrenheit), a heat that kills most organisms; others thrive at the seriously acidic pH of zero.

They are not restricted to life at the fringes, however. As we have learned how to detect them, archaea have turned up all over the place. One survey estimated that they account for as much as 20 percent of all microbial cells in the ocean, and they’ve been discovered living in soil, swamps, streams and lakes, sediments at the bottom of the ocean, and so on. They are also routinely found in the bowels of the Earth — and the bowels of animals, including humans, cows and termites, where they produce methane. Indeed, the archaeon known as Methanobrevibacter smithii may account for as much as 10 percent of all the microbial cells living in your gut.

But here’s the thing. The tree of life falls into three big lineages, or realms of life. (Confession: the technical term is “domains,” not “realms,” but I’m taking poetic license.) The most familiar realm comprises the eukaryotes — which is the blanket term for most of the organisms we are familiar with, be they mushrooms, water lilies, tsetse flies, humans or the single-celled beasties that cause malaria. Eukaryotes have many distinguishing features, including the fact that they keep their genes in a special compartment known as the cell nucleus.

The second member of the trinity is made up of bacteria. We tend to associate bacteria with disease — for they can cause a range of nasty infections, including pneumonia, syphilis, leprosy, tuberculosis and the like. But in fact, most bacteria lead blameless lives (some of which I have written about in previous columns). There are many differences between eukaryotes and bacteria; but one of the most obvious is that bacteria do not sequester their DNA in a cell nucleus.

Archaea

Methanogens, a type of archaea

The third great lineage of living beings is the archaea. At first glance, they look like bacteria — and were initially presumed to be so. In fact, some scientists still classify them as bacteria; but most now consider that there are enough differences between archaea and bacteria for the archaea to count as a separate realm.

The most prominent of these differences lies in the structure of the ribosome — the piece of cellular machinery that is responsible for turning the information contained in DNA into proteins. Indeed, it was the discovery of the archaeal ribosome by the biologist Carl Woese in the 1970s that led to their being recognized as the third branch of the tree of life.

What else sets them apart? They sometimes come in peculiar shapes: Haloquadratum walsbyi is rectangular, for example. Some archaea are ultra-tiny, with cell volumes around 0.009 cubic microns. (For comparison, human red blood cells have a volume of around 90 cubic microns. A micron is a millionth of a meter — which is extremely small.)

More diagnostic: archaeal cell membranes have a different structure and composition from those of bacteria or eukaryotes. And although archaea organize their DNA much as bacteria do (they also have no cell nucleus, for example), many aspects of the way the DNA gets processed are distinctly different. Instead, the processing is more similar to what goes in within eukaryotic cells. Archaea also have large numbers of genes that are not found in the other groups.

But to me their most telling feature is that they have their own set of extremely weird viruses. Not only do archaeal viruses also come in odd shapes — some of them look like little bottles — but the set of genes they have is unlike that of viruses that parasitize bacteria or eukaryotes. In other words, viruses can also be divided into three big groups: those that attack bacteria, those that attack eukaryotes and those that attack archaea.

The archaea still hold many mysteries. Few of them can be grown in the laboratory, so they are hard to study in detail; many of them are known from their DNA alone. Moreover, their exact position on the tree of life — when they evolved relative to the other two groups — remains disputed. Yet it may be that archaea feature in our ancestry: according to one view, eukaryotes themselves evolved from an ancient fusion between a bacterium and an archaeon.

But whether this is the case, or whether they are merely co-occupants of the planet, let’s hear it for these Other Life-forms!

Notes:

For a delightful introduction to the archaea, see Howland, J. L. 2000. “The Surprising Archaea: Discovering Another Domain of Life.” Oxford University Press. For a more technical overview, see Cavicchioli, R. (editor). 2007. “Archaea: Molecular and Cellular Biology.” ASM Press. See page 21 for a photograph of the square archaeon, Haloquadratum walsbyi; this book also contains detailed descriptions of how archaea differ from eukaryotes and bacteria.

For archaea thriving at temperatures of 121 degrees C, see Kashefi, K. and Lovley, D. R. 2003. “Extending the upper temperature limit for life.” Science 301: 934. For archaea growing at zero pH, see Fütterer, O. et al. 2004. “Genome sequence of Picrophilus torridus and its implications for life around pH 0.” Proceedings of the National Academy of Sciences USA 101: 9091-9096.

For an overview of places where archaea have been found, see Chaban, B., Ng, S. Y. M., and Jarrell, K. F. 2006. “Archaeal habitats—from the extreme to the ordinary.” Canadian Journal of Microbiology 52: 73-116. For archaeal residents of animal guts, see Lange, M., Westermann, P., and Ahring, B. K. 2005. “Archaea in protozoa and metazoa.” Applied Microbiology and Biotechnology 66: 465-474. For archaea comprising 20 percent of ocean microbes, see DeLong, E. and Pace, N. R. 2001. “Environmental diversity of bacteria and archaea.” Systematic Biology 50: 470-478. For Methanobrevibacter smithii comprising 10 percent of the human gut microbial population, see Samuel, B. S. et al. 2007. “Genomic and metabolic adaptations of Methanobrevibacter smithii to the human gut.” Proceedings of the National Academy of Sciences USA 104: 10643-10648.

Descriptions of eukaryotes and bacteria can be found in any general biology textbook. For the view that archaea are merely a type of exotic bacteria, see page 123 of Cavalier-Smith, T. 2010. “Deep phylogeny, ancestral groups and the four ages of life.” Philosophical Transactions of the Royal Society B 365: 111-132. For a robust account of the three branches view of the tree of life, see for example, Pace, N. R. 2009. “Mapping the tree of life: progress and prospects.” Microbiology and Molecular Biology Reviews 73: 565-576.

For ultra-tiny archaea (and for the volume of 0.009 cubic microns), see Baker, B. J. et al. 2010. “Enigmatic, ultrasmall, uncultivated Archaea.” Proceedings of the National Academy of Sciences USA 107: 8806-8811. I took the volume of the human red blood cell from table 1 of Gregory, T. R. 2000. “Nucleotypic effects without nuclei: genome size and erythrocyte size in mammals.” Genome 43: 895-901.

For the bizarre features of archaeal viruses, see Prangishvili, D., Forterre, P. and Garrett, R. A. 2006. “Viruses of the Archaea: a unifying view.” Nature Reviews Microbiology 4: 837-848. The origin of eukaryotes, and whether it involved the fusion between a bacterium and an archaeon, is much disputed. See, for example, Yutin, N. et al. 2008. “The deep archaeal roots of eukaryotes.” Molecular Biology and Evolution 25: 1619-1630; Kurland, C. G., Collins, L. J., and Penny, D. 2006. “Genomics and the irreducible nature of eukaryotic cells.” Science 312: 1011-1014; and Hartman, H. and Fedorov, A. 2002. “The origin of the eukaryotic cell: a genomic investigation.” Proceedings of the National Academy of Sciences USA 99: 1420-1425.

Many thanks to Jonathan Swire for insights, comments and suggestions.

Olivia Judson, New York Times

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Full article and photos: http://opinionator.blogs.nytimes.com/2010/05/18/life-in-the-third-realm/

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A jaguar in the Pantanal, Brazil, the world’s largest wetland.

Héctor Porras-Valverdo tried to adopt a Zen attitude when he discovered recently that jaguars had turned two of his cows into carcasses.

The jaguars’ numbers may have dwindled, but they still roam the forests here in eastern Costa Rica, making their presence known by devouring the occasional chicken, pig or cow.

“I understand cats do this because they need to survive,” said Mr. Porras-Valverdo, 41, a burly dairy farmer.

A few years ago, he acknowledged, his first reaction might have been to reach for a gun. But his farm now sits in the middle of land that Costa Rica has designated a “jaguar corridor” — a protected pathway that allows the stealthy, nocturnal animals to safely traverse areas of human civilization.

In the past few years, such corridors have been created in Africa, Asia and the Americas to help animals cope with 21st-century threats, from encroaching highways and malls to climate change.

These pathways represent an important shift in conservation strategy. Like many other nations, Costa Rica has traditionally tried to protect large mammal species like jaguars by creating sanctuaries — buying up land and giving threatened animals a home where they can safely eat, fight and breed to eternity.

But in the past decade or so, scientists have realized that connecting corridors are needed because many species rely for survival on the migration of a few animals from one region to another, to intermix gene pools and to repopulate areas devastated by natural disasters or disease. Placing animals in isolated preserves, studies have found, decreases diversity and risks dulling down a species — like preventing New Yorkers and Californians from getting together to procreate.

“It was kind of an epiphany,” said Alan Rabinowitz, a zoologist who is president of Panthera, an organization that studies and promotes conservation of large cats. “We were giving them nice land to live on when what they were doing — and what they needed — was an underground railway.”

He said critical migration routes were especially vulnerable in rapidly developing countries, where new roads, shopping malls, dams, playgrounds and subdivisions could spring up overnight, blocking the animals’ passage. To correct this oversight, Costa Rica and other countries have begun identifying and protecting corridors for jaguars and other large mammals, like tigers, snow leopards and pandas.

Most of the corridors are not obviously demarcated pathways, but virtual trails, “protected” in the sense that builders and planners are not permitted to introduce obstacles to the animals’ movements through the area.

The idea is not to stop building entirely, but to adjust development so that animals can move through landscapes that humans also occupy. A tall fence surrounding a shopping mall may be forbidden, for example, or a two-lane road may have to be substituted for a proposed four-lane highway.

Local residents must also be persuaded not to shoot wild intruders or otherwise drive them away when they are in transit, a shift in thinking that is already taking root here.

“Of course jaguars sometimes have conflicts with communities, but now people have been educated to change their thinking — not to see them as so dangerous,” said Víctor Fallas Ramírez, an agronomist who grows ornamental plants here.

The threat of global warming has added to the urgency of creating corridors because animals will need to shift habitats as temperatures rise from climate change.

“This is an idea that people are finding very compelling, and especially compelling now because with changing climate, species will need the capacity to move,” said Norman Christensen, a professor of ecology at Duke University, whose team is working to define corridors in Central America, India and Africa.

While Dr. Christensen called Costa Rica “the poster child” for its efforts, he said corridors for large mammals were also being created in places like Uganda and China. The World Bank is financing corridor projects in Brazil and Peru; more important, the bank’s transportation planners are working with conservationists to ensure that building highways and laying train tracks so humans can move freely does not destroy that movement for animals, Dr. Christensen said.

Part of the reason that conservationists had in the past focused exclusively on preserves was that there was a lack of good data on the travel and breeding patterns of large animals like jaguars; these big predators favor dense jungles and are nocturnal and extraordinarily shy.

So when new techniques allowed scientists to take a first look at the jaguar genome a decade ago, they were shocked to discover that jaguars from the northern reaches of Mexico had exactly the same genetic makeup as those from the southern tip of South America.

That meant that over time, some jaguars were moving up and down the Americas to breed; otherwise, the isolation of jaguar populations in different regions would have caused their genetic makeups to diverge. At least some males from Colombia were traveling to Panama to mate, and others were moving from Mexico to Belize.

“It was surprising, but it seemed to say they had one continuous habitat,” said Dr. Rabinowitz, the zoologist.

Scientists were convinced that jaguars would never cross a water barrier as wide as the Panama Canal, smack in the middle of their extended habitat. But when they set up cameras to spot jaguars near the canal, they discovered that, every so often, a brave animal took the plunge, ensuring the continuity of genes in the north and south.

Costa Rica now requires developers to consider whether a new construction project would interrupt an essential corridor, or else to make other arrangements for jaguars to travel safely through the area.

The fact that jaguars and other large cat species travel at night and do not hunt when they are on the move makes it easier for them to co-exist with humans.

“The bottom line is big cats can live with people,” Dr. Rabinowitz said. “That’s not true of all animals.”

He continued, “The problem with the paradigm of conservation is it’s been seen as a confrontation between nature and development, that won’t let progress happen.”

In Costa Rica, Panthera is conducting research to better define the routes taken by jaguars and lobbying politicians and developers to respect them. The organization also sponsors community outreach programs to resolve what the researchers term “jaguar conflict issues.”

“Many places don’t want the corridors,” said Roberto Salom, Panthera’s regional coordinator here. “We’ve made alliances with lots of leaders and educators, but it’s a very slow process.”

Here in the jungles of Central America, jaguars are regarded as mystical and dangerous. According to local legend, indigenous people turn into jaguars when they enter the jungle, and then shake off their spots when they return to the village.

“I’ve seen the tracks, but never an animal,” said Enoc Bajo Chiripó, an indigenous leader who is working with the group. “But you can smell when they’re around.”

Families in the region tell jaguar stories the way New Yorkers talk about their families’ arrivals at Ellis Island.

“My grandmother saw it at the place where agouti and peccaries come to eat,” said Jordi Ortiz-Camacho, 12, speaking of a jaguar. “My grandfather killed it with a stick because his gun didn’t work.”

While local farmers are now willing to forgive a dead cow or two to allow jaguars to survive as a species, they are often reluctant to make larger sacrifices. Just outside Las Lomas, a proposed hydroelectric project would involve building a huge dam across a valley, creating a body of water a third of a mile wide and more than three miles long. As planned, it would block a jaguar corridor.

The new project will mean jobs, an increase in property values and improved basic services for the area, including roads and piped water, said Mr. Fallas Ramírez, the agronomist. And the community, he said, cannot just forsake all that.

“For us, and the jaguars, it’s just an obstacle,” said Mr. Salom, the biologist, who is looking into alternative solutions, like an animal bridge or a smaller dam. “So we’re thinking, ‘How can we mitigate this?’ ”

Elisabeth Rosenthal, New York Times

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Full article and photo: http://www.nytimes.com/2010/05/12/science/earth/12jaguar.html

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A sunnier outlook

Artificial photosynthesis

Using a virus to help produce energy the way plants do

The ultimate green-energy source

IN HIS latest novel, “Solar”, Ian McEwan’s protagonist is Michael Beard, a Nobel prize-winning physicist who has been resting on his laurels for two decades specialising in “after-dinner speeches and eulogies for retiring or about-to-be-cremated colleagues”. To reinvigorate his career, Dr Beard steals a postdoctoral scientist’s discovery of artificial photosynthesis, described as “an engine running on nothing”, and tries to harness it.

That may be fiction, but it is not fantasy. Photosynthesis, the process by which plants convert energy from sunlight into chemical energy, is one of the most important chemical reactions on earth, so there are many efforts under way to try to replicate it. The process is, though, proving to be particularly difficult to emulate with any great efficiency.

During photosynthesis two “half-reactions” take place. First, sunlight is used to split water into hydrogen and oxygen. Plants do this with a complex molecular “photosystem” that uses the energy of sunlight to break apart water molecules, liberating electrons, hydrogen ions and oxygen. Then, in the second half-reaction, the electrons and hydrogen ions combine with carbon dioxide to create energy-rich carbohydrates, such as glucose, which plants use to grow.

It is the first half-reaction which provides the potential for an energy source. Sunlight can already be used to split water artificially with solar panels generating the electricity needed for a process called electrolysis. The hydrogen obtained from water can then be stored and used in, say, a fuel cell to produce power when the sun does not shine. But the process is not particularly productive, given the present output of solar panels, and it is costly.

Researchers have tried to mimic the process used by plants with experimental systems that use some of the components of photosynthesis, such as chlorophyll, which makes plants green and helps trap light, and catalysts which facilitate the process of converting carbon dioxide, water and sunlight. But some of the materials and catalysts have turned out to be unstable and inefficient in the laboratory.

Viral power

Now Angela Belcher of the Massachusetts Institute of Technology and her colleagues have succeeded in mimicking the first part of photosynthesis by using a genetically modified virus to help split water into hydrogen and oxygen. The researchers took a virus called M13, which normally infects bacteria and is harmless to humans, and engineered it to assemble on its coating both iridium oxide, one of the catalysts used by researchers, and light-sensitive biological pigments called zinc porphyrins, which act as an antenna to capture the light.

What the virus provides, says Dr Belcher, is a sort of scaffolding or frame around which the components used in artificial photosynthesis can attach themselves, and do so at the right distances from one another to trigger the water-splitting reaction. The arrangement provided by the virus greatly improves the efficiency of the reaction. In addition, the structure also assembles itself. There are problems. One is that viruses tend to clump together, which hampers their performance. To prevent this from happening, the team embedded the viruses into a microgel matrix, which preserved their light-collecting abilities.

In their research, recently published in Nature Nanotechnology, Dr Belcher and her colleagues concentrated on the more technically challenging production of oxygen, but they now hope to complete the process by recombining the hydrogen ions and harvesting hydrogen gas. This would provide a way of capturing sunlight, in much the same way as plants do, and then storing the energy in the form of hydrogen gas. The energy is then released when the hydrogen is burned or used in a fuel cell to make electricity.

The researchers are also seeking a catalyst that is cheaper than one based on iridium, which is relatively expensive. In a few years, Dr Belcher speculates, it may be possible to build a prototype machine to split water efficiently using sunlight. Meanwhile, they should watch out for any disgruntled physicists desperate to boost their careers.

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Full article and photo: http://www.economist.com/science-technology/displaystory.cfm?story_id=16004354&source=hptextfeature

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Pea aphids are the first creatures in the animal kingdom to have been shown to produce carotenoids.

There’s a reason your parents kept after you to eat your carrots. The vegetables (and lots of others, too) supply carotenoids, compounds that are good for vision and overall health. Animals, humans included, cannot manufacture them.

Check that. Researchers have found the first evidence of carotenoid production in a member of the animal kingdom. The animal in question? A tiny aphid.

Nancy A. Moran, a researcher at the University of Arizona who is soon to be at Yale, and Tyler Jarvik, an Arizona colleague, report in Science that the pea aphid, Acyrthosiphon pisum, produces carotenoids using a genetic sequence that it picked up from fungi as it evolved, a process called lateral gene transfer. The carotenoid production contributes to an unusual characteristic of pea aphids: they come in two colors, red and green.

Dr. Moran, who studies genomic evolution, made the discovery while searching through the pea aphid genome, which was sequenced last year. The genes for carotenoid production are similar for every organism that makes them, she said, and they just “popped up” when she did the search. Further analysis showed that they came from fungi, and that the transfer occurred tens of millions of years ago.

All pea aphids have this carotenoid-making machinery, but the researchers found that some have a genetic mutation and cannot produce certain carotenoids that are red in color. So these aphids are green, while those without the mutation are red.

This division in color has an ecological effect: red aphids are more likely to be eaten by predators, while green ones are more likely to be invaded by parasites. In turn, this split between predation and parasitism helps maintain the split in color, ensuring that neither red nor green prevails over the long term.

Henry Fountain, New York Times

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Full article and photo: http://www.nytimes.com/2010/05/04/science/04obaphid.html

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The human ego has never been quite the same since the day in 1960 that Jane Goodall observed a chimpanzee feasting on termites near Lake Tanganyika. After carefully trimming a blade of grass, the chimpanzee poked it into a passage in the termite mound to extract his meal. No longer could humans claim to be the only tool-making species.

The deflating news was summarized by Ms. Goodall’s mentor, Louis Leakey: “Now we must redefine tool, redefine Man, or accept chimpanzees as human.”

So what have we actually done now that we’ve had a half-century to pout? In a 50th anniversary essay in the journal Science, the primatologist William C. McGrew begins by hailing the progression of chimpanzee studies from field notes to “theory-driven, hypothesis-testing ethnology.”

He tactfully waits until the third paragraph — journalists call this “burying the lead” — to deliver the most devastating blow yet to human self-esteem. After noting that chimpanzees’ “tool kits” are now known to include 20 items, Dr. McGrew casually mentions that they’re used for “various functions in daily life, including subsistence, sociality, sex, and self-maintenance.”

Sex? Chimpanzees have tools for sex? No way. If ever there was an intrinsically human behavior, it had to be the manufacture of sex toys.

Considering all that evolution had done to make sex second nature, or maybe first nature, I would have expected creatures without access to the Internet to leave well enough alone.

Only Homo sapiens seemed blessed with the idle prefrontal cortex and nimble prehensile thumbs necessary to invent erotic paraphernalia. Or perhaps Homo habilis, the famous Handy Man of two million years ago, if those ancestors got bored one day with their jobs in the rock-flaking industry:

“Flake, flake, flake.”

“There’s gotta be more to life.”

“Nobody ever died wishing he’d spent more time making sharp rocks.”

“What if you could make a tool for… something fun?”

I couldn’t imagine how chimps managed this evolutionary leap. But then, I couldn’t imagine what they were actually doing. Using blades of grass to tickle one another? Building heart-shaped beds of moss? Using stones for massages, or vines for bondage, or — well, I really had no idea, so I called Dr. McGrew, who is a professor at the University of Cambridge.

The tool for sex, he explained, is a leaf. Ideally a dead leaf, because that makes the most noise when the chimp clips it with his hand or his mouth.

“Males basically have to attract and maintain the attention of females,” Dr. McGrew said. “One way to do this is leaf clipping. It makes a rasping sound. Imagine tearing a piece of paper that’s brittle or dry. The sound is nothing spectacular, but it’s distinctive.”

O.K., a distinctive sound. Where does the sex come in?

“The male will pluck a leaf, or a set of leaves, and sit so the female can see him. He spreads his legs so the female sees the erection, and he tears the leaf bit by bit down the midvein of the leaf, dropping the pieces as he detaches them. Sometimes he’ll do half a dozen leaves until she notices.”

And then?

“Presumably she sees the erection and puts two and two together, and if she’s interested, she’ll typically approach and present her back side, and then they’ll mate.”

My first reaction, as a chauvinistic human, was to dismiss the technology as laughably primitive — too crude to even qualify as a proper sex tool. But Dr. McGrew said it met anthropologists’ definition of a tool: “He’s using a portable object to obtain a goal. In this case, the goal is not food but mating.”

Put that way, you might see this chimp as the equivalent of a human (wearing pants, one hopes) trying to attract women by driving around with a car thumping out 120-decibel music. But until researchers are able to find a woman who admits to being anything other than annoyed by guys in boom cars, these human tools must be considered evolutionary dead ends.

By contrast, the leaf-clipping chimps seem more advanced, practically debonair. But it would be fairer to compare the clipped leaf with the most popular human sex tool, which we can now identify thanks to the academic research described last year by my colleague Michael Winerip. The researchers found that the vibrator, considered taboo a few decades ago, had become one of the most common household appliances in the United States. Slightly more than half of all women, and almost half of men, reported having used one, and they weren’t giving each other platonic massages.

Leaf-clipping, meanwhile, has remained a local fetish among chimpanzees. The sexual strategy has been spotted at a colony in Tanzania but not in most other groups. There has been nothing comparable to the evolution observed in distributors of human sex tools: from XXX stores to chains of cutely named boutiques (Pleasure Chest, Good Vibrations) to mass merchants like CVS and Wal-Mart.

So let us, as Louis Leakey suggested, salvage some dignity by redefining humanity. We may not be the only tool-making species, but no one else possesses our genius for marketing. We reign supreme, indeed unrivaled, as the planet’s only tool-retailing species.

Now let’s see how long we hold on to that title.

John Tierney, New York Times

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Full article and photo: http://www.nytimes.com/2010/05/04/science/04tier.html

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The three spined stickleback makes fine-tuned decisions

It’s a fact of life in the animal world that some fish (and birds, mammals, reptiles, insects, crustaceans — you name it) eat their young.

The three-spined stickleback, a species found around much of the globe, is one such finned filial cannibal. The males, who care for the eggs, are known to devour whole or parts of clutches. Sometimes, however, they might have reason to — since sticklebacks are known to “sneak” fertilizations, another fish might be the father of some of the eggs.

A study by Marion Mehlis of the University of Bonn in Germany and colleagues looked at the question of whether a male stickleback somehow assessed the paternity of the eggs in its care in deciding whether or not to eat them.

As they report in The Proceedings of the Royal Society B: Biological Sciences, the answer was yes. What’s more, the researchers found that the fish made fairly fine-tuned decisions.

The researchers manipulated the clutches that individual males cared for, replacing up to 100 percent of the eggs fertilized by the male with eggs fertilized by another male. They found that the higher the percentage of “alien” eggs, the more likely the male was to completely cannibalize the clutch. The researchers suggest that the fish probably take their cues from the odor of the developing eggs as the paternal genes start to kick in.

Cannibalism of a clutch with a high proportion of alien eggs makes sense for the fish, because it avoids putting a lot of energy into producing offspring that carry another fish’s genes, and because by eating the eggs it gets energy to rear future clutches of its own eggs.

Henry Fountain, New York Times

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Full article and photo: http://www.nytimes.com/2010/04/27/science/27obcannibal.html

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One thing about evolution — you never know what’s going to influence it. Take the European corn borer, for instance. Researchers have just made a strong case that a certain aspect of its behavior has evolved because of human harvesting of corn.

The corn borer, Ostrinia nubilalis, is a pest caterpillar that spends spring and summer feeding on its host corn stalk before spinning a cocoon for the winter. It is almost identical to a related species, O. scapulalis — in fact, until recently the two were thought to be one. But O. scapulalis’s host plant is not corn, but a weed known as mugwort.

In a paper in The Proceedings of the Royal Society B: Biological Sciences, Vincent Calcagno, a biologist now at McGill University, and colleagues show that, behaviorally, that makes all the difference in the world. For mugwort is neither harvested nor grazed, while corn has been harvested for centuries.

In harvesting, either mechanically or by hand, the stalks are cut off some height — often 6 to 15 inches — above the ground. Any corn borers above that height will surely not survive when the stalks are shredded, burned or fed to animals.

Through field and laboratory tests, the researchers discovered that before it stops eating and spins its cocoon, the corn borer travels down the stalk, usually reaching a height at which it is safe. O. scapulalis does not exhibit this descending behavior, called geotaxis.

Dr. Calcagno said the likeliest explanation for the behavior is the selection pressure of harvesting — over generations, those caterpillars that did not descend, or did not go far enough, did not survive. “There could be other reasons that explain the tendency to move down, but we have no evidence of what those reasons could be,” he said. This harvesting-induced selection, he added, could be widespread in other pests.

Henry Fountain, New York Times

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Full article and photo: http://www.nytimes.com/2010/04/27/science/27obborer.html

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After it is released from a flower’s anther, a pollen grain walks a humidity tightrope. It dries up a bit as it travels through the air, the cellular material inside becoming dormant so it survives until it reaches the humid environment of another flower’s stigma. But it can’t become so dry that the material dies.

A scanning electron micrograph of a dehydrated Lily pollen grain.

Pollen grains achieve the proper state of desiccation by folding in on themselves as they dry, which reduces the rate of water loss (and also accommodates the reduced volume of water, making the grain smaller). It’s an elegant trick, and the structure of the pollen grain wall determines how it occurs, according to research published in The Proceedings of the National Academy of Sciences.

Eleni Katifori, previously at Harvard and at Rockefeller University, and colleagues studied the folding of pollen from lilies and other flowers (a video of folding grains is at nytimes.com/science). The walls of pollen grains have weaker, more flexible sections called apertures, and Dr. Katifori said those sections guide the folding process. Like origami, in which paper stretches only at the creases, pollen grains deform at the apertures “so the rest can fold without stretching,” she said.

“It’s like pulling the air out of a beach ball,” she said. “Parts of the wall have to comply to accommodate the change of volume.”

Dr. Katifori said the goal of the research was to discover the basic principles by which the folding occurs as a way of understanding some of the functional demands that drive the great diversity of pollen grain structures in nature. But she said that the work might also prove useful to those who design structures. “I could imagine that engineers could get inspiration from just looking at pollen grains,” she said.

Henry Fountain, New York Times

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Full article and photo: http://www.nytimes.com/2010/04/27/science/27obpollen.html

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Rare video footage taken at a wildlife park has showed that chimpanzees react to the death of a group member just like humans do when a close relative dies, researchers said Monday.

Videos of a group of four chimpanzees at Scotland’s Blair Drummond Safari and Adventure Park showed three of the animals caressing and grooming the fourth, a dying female, more than usual, said James Anderson, a lecturer in psychology at Scotland’s University of Stirling.

The videos also showed that the three chimpanzees tested the elderly female, Pansy, for signs of life at the moment of death, Anderson said. Pansy’s daughter lay near her mother’s body throughout the night, and all the chimpanzees were subdued in the next few days.

”It’s the first time to our knowledge that people have been able to capture on video the precise moment at which an adult chimpanzee dies in the midst of his or her group,” said Anderson, who co-authored a study to be published Tuesday in the journal Current Biology.

Researchers have not been able to observe how chimpanzees react to death because in the wild a dying animal usually isolates itself and crawls into cover for protection, Anderson said. In zoos, sick animals are usually separated from the group and euthanized.

Staff at the Scottish wildlife park anticipated Pansy’s death and recorded the group’s behavior with overhead video cameras, which had been placed above the animals’ sleeping platforms for a previous study.

The three surviving chimpanzees — all of whom had been living with Pansy as a group for more than 20 years — gathered around her and caressed her in the ten minutes preceding her death. When she died they inspected her mouth and lifted her head and shoulder to try to shake her into life, Anderson said.

The animals stopped grooming Pansy and left her after her death, although her daughter later came back to build a nest and lie by her all night long.

Alasdair Gillies, the head keeper at the park and co-author of the study, said the animals were quieter than normal and lost their appetites after the death.

”I think this video footage showed the chimpanzees were aware something strange and different was happening but other research will have to be conducted to see how much they understood what was going on. We are just opening the debate,” he said.

The researchers said the study suggested that chimpanzees — known to have a developed sense of self and empathy toward others — were more like humans than previously thought.

”We were careful to avoid anthropomorphism, but it became very difficult not to realize some of these things are strikingly similar to human responses to dying individuals,” Anderson said.

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Full article: http://www.nytimes.com/aponline/2010/04/26/science/AP-EU-Britain-Mourning-Chimpanzees.html

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Once feared extinct, the giant Palouse earthworm, reputed to grow up to three feet long and smell like lilies, has been found alive.

It turns out though, experts say, the worm is not a giant, nor does it have a lilylike scent.

Researchers thought the translucent worm with the pink head, last seen in the 1980s, might be extinct because its habitat, the Palouse prairie region of Idaho and Washington, is almost gone. On March 27, however, Karl Umiker, a University of Idaho research support scientist, working with Shan Xu, a graduate student from Chengdu, China, discovered two giant Palouse earthworms, a juvenile and an adult, on a small patch of native prairie near Moscow, Idaho.

As it turns out, the worms are bigger than night crawlers but not giant. The two specimens, the adult of which had to be killed and dissected to determine it was indeed a giant Palouse earthworm, were about seven inches long when they came from the ground.

“But when we stretched it out and relaxed it, the adult earthworm got bigger,” said Jodi Johnson-Maynard an associate professor of soil and water management and Mr. Umiker’s supervisor. “It’s between nine and 10 inches.”

She admits that’s a far cry from earlier claims of three-foot worms. “We tried to track that story down,” Dr. Johnson-Maynard said, and discovered that many years ago there was one giant specimen. “Apparently some boy was swinging it in the air like a rope and it stretched.”

Giant earthworms do exist in Africa and Australia, she said, and so it was thought that a North American version was possible.

And the fragrance of lilies? “That I have never noted,” Dr. Johnson-Maynard said. She did not know the origin of that claim.

Still, Dr. Johnson-Maynard said finding the worms was a scientific coup. “Most people thought it was extinct, or that it never even existed,” she said, “like the Loch Ness monster.”

The idea of a giant, white, perfumed earthworm churning its way through the prairies of Idaho has captured imaginations, and the project has received a lot more news media attention than comparable worm studies.

The worms are unusual — they are transparent, and their organs and food can be discerned through their skin.

Samuel James, an earthworm taxonomist at the University of Kansas Biodiversity Institute, performed the dissection. “Yes, in all particulars, it matches the original description of the giant Palouse earthworm,” Dr. James said. The species was first described in 1897.

“I hate to disappoint the world,” he continued, “but the term giant doesn’t really fit.”

The last live worms were found in the 1980s. Worms were found by researchers in 2005 and 2007, but they were killed during recovery. There were numerous sightings in the 19th century before most of the native prairie was plowed up for wheat.

Dr. Johnson-Maynard was disappointed the adult had to be killed to be identified, but inspecting digestive organs is the only way to tell for sure. Now, however, she said, DNA from the sacrificial worm should enable less drastic measures.

Dr. Johnson-Maynard suspects that there are more giant Palouse earthworms, and that they are considered rare in part because they are so hard to find. While most worms live in the top foot of soil, she said, “the giant Palouse can burrow much deeper, about 15 feet.” They can also sense disturbance and flee to deeper ground when researchers are digging.

The researchers used an electroshock device to find the worms. Called the octet method, it involves sticking eight electrodes into the ground in a one-foot circle pattern, and sending electricity through them. It is believed to be what brought the worms to the surface.

The scientific name for the worm is Driloleirus americanus, a separate genus and species than other worms. The creature is different than other worms in a couple of ways. It has more nephidia, a kidney-like organ that allows it to live in dryer conditions than other worms. And their clitellum, a smooth band that all worms have, is in a different location.

Meanwhile another worm, in the same genus as the giant Palouse, has been discovered by Dr. James in Washington State, at Beacon Rock State Park. “It’s translucent, and if it’s been eating black dirt you can see the dark stuff moving around inside,” he said.

Environmentalists have petitioned the federal government to list the giant Palouse earthworm as endangered, and considering the near complete loss of the creature’s habitat, Dr. James thinks listing is prudent.

The remaining juvenile giant Palouse earthworm, meanwhile, is resting comfortably, Dr. Johnson-Maynard said. “We have it in a cooler in soil with ice packs.”

Jim Robbins, New York Times

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Full article: http://www.nytimes.com/2010/04/27/science/27earthworm.html

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STICK-TO-IT-IVENESS Clockwise from top left, the sandcastle worm builds its home by using tentacles to grab sand and shell bits and glues them with adhesive from an organ on its head; its tube-shaped dwelling; two beads of a worm’s home, microscopically enlarged; a section of a sandcastle worm colony.

Along one wall of Russell J. Stewart’s laboratory at the University of Utah sits a saltwater tank containing a strange object: a rock-hard lump the size of a soccer ball, riddled with hundreds of small holes.

It has the look of something that fell from outer space, but its origins are earthly, the intertidal waters of the California coast. It’s a home of sorts, occupied by a colony of Phragmatopoma californica, otherwise known as the sandcastle worm.

Actually, it’s more of a condominium complex. Each hole is the entrance to a separate tube, built one upon another by worm after worm.

P. californica is a master mason, fashioning its tube, a shelter that it never leaves, from grains of sand and tiny bits of scavenged shell. But it doesn’t slather on the mortar like a bricklayer. Rather, using a specialized organ on its head, it produces a microscopic dab or two of glue that it places, just so, on the existing structure. Then it wiggles a new grain into place and lets it set.

What is most remarkable — and the reason these worms are in Dr. Stewart’s lab, far from their native habitat — is that it does all this underwater.

“Man-made adhesives are very impressive,” said Dr. Stewart, an associate professor of bioengineering at the university. “You can glue airplanes together with them. But this animal has been gluing things together underwater for several hundred million years, which we still can’t do.”

Dr. Stewart is one of a handful of researchers around the country who are developing adhesives that work in wet conditions, with worms, mussels, barnacles and other marine creatures as their guide. While there are many possible applications — the Navy, for one, has a natural interest in the research, and finances some of it — the biggest goal is to make glues for use in the ultimate wet environment: the human body.

It is too early to declare the researchers’ work a success, but they are testing adhesives on animal bones and other tissues and are optimistic that their approaches will work. “I would have moved on to something else if I didn’t think so,” said Phillip B. Messersmith, a Northwestern University professor who is developing adhesives based on those made by mussels and is testing whether they can be used to repair tears in amniotic sacs, among other applications.

While some skin sealants — mostly of the cyanoacrylate, or superglue, variety — are on the market, their effectiveness is limited. They often cannot be used, for example, on incisions where the skin is pulled or stretched, or must be used in tandem with sutures or staples. Adhesives strong enough to hold skin together under tension, or repair bone or other internal tissues — without inviting attack by the body’s immune system — have eluded researchers.

Nature shows how it can be done, said J. Herbert Waite, a professor at the University of California, Santa Barbara, who did much of the early work of identifying the adhesives that mussels use to stick to rocks and other surfaces. But researchers should view nature’s approach as a general guide, he said, rather than a precise pathway.

“In my view of bioinspired research or materials, I almost always don’t think it’s safe to be slavishly wed to the specific chemistry,” Dr. Waite said, “but rather to distill the important concepts that can then be mimicked.”

So the goal of these researchers is not to duplicate natural adhesives that work well underwater, but to imitate them and make glues that are even better suited for humans. “We want to take elements of the structural adhesives that chemists have made and combine them with the unique elements that nature has used,” Dr. Stewart said.

Synthetic adhesives might not only work better, but they should also be able to be produced in large quantities. Marine organisms make their glues in very small amounts — the typical dollop from a sandcastle worm, for example, is on the order of 100 picoliters. Even if it could somehow be collected before it set, it would take roughly 50 million dollops to make a teaspoon.

“At the end of the day, the single biggest reason to do this is you can get more stuff,” said Jonathan Wilker, an associate professor of inorganic chemistry at Purdue University who works on analogues of mussel adhesives and studies oysters, barnacles and other organisms as well.

But there are several hurdles to making glues that work underwater, Dr. Wilker said. “One is that whenever the surface is really wet, you’re going to be bonding to the surface layer of water, rather than the surface itself. So it’s going to lift off.”

Another is that in order to cure, glues need a little water or none at all — they need to dry out. Most will not cure underwater, but those that do tend to set as soon as they are out of the container, overwhelmed by all the water. Beyond that, Dr. Messersmith said, as with any glue, “adhesion is a complicated thing, even when it appears very simple.”

“There are events going on at the interface of adhesive and surface, and there’s the strength of the adhesive itself,” he said. “If you have one but not the other, you’re nowhere, really, because somewhere you’ll have a weak point in the system and it will break.”

The sandcastle worm resolves the underwater issues neatly. The proteins that are the basis of its adhesive contain phosphate and amine groups, molecular fragments that are well-known adhesion promoters. “Those side chains are probably what helps it wet the surface in the first place,” Dr. Stewart said.

The worm produces the glue in two parts, with different proteins and side groups in each. The two are made separately in a gland, and, like an epoxy, come together only as they are secreted. When they mix they form a compound that, even though water based, does not dissolve. The glue sets initially in about 30 seconds, probably triggered by the abrupt change in acidity — it is far more acidic than seawater, Dr. Stewart said. Over the next six hours, the adhesive hardens completely as cross-links form between the proteins. “It turns into this thing that has the consistency of shoe leather,” he said. “It’s still flexible but very tough.”

Like other researchers, Dr. Stewart decided to use synthetic polymers as the backbone for his adhesive, and to ignore many other aspects of the worm’s chemistry. “Who says the exact amino acids are important?” he said, citing one example. “That’s just something the worm is stuck with.

“On the other hand, if we just decide maybe the real important part is the side chains, that’s very simple to copy with a synthetic polymer.”

Dr. Stewart’s adhesive forms what chemists call a complex coacervate, a kind of molecular circling of the wagons against water. So it’s an injectable, immiscible liquid. “Perfect for a water-borne underwater adhesive,” he said. But unlike the worm, he can tweak the chemistry to make it cure faster or slower depending on the application.

Dr. Stewart says the glue appears to be strong enough to repair fractures in craniofacial bones, an application he is studying with rats. He also thinks it may be useful for repairing corneal incisions, and for setting other bone fractures more precisely, by anchoring small pieces that cannot be secured with pins or screws. “But we don’t have any fantasies about gluing femurs back together,” he said.

Dr. Stewart has worked with sandcastle worms since 2004, and recently began studying another group of tube-building creatures, caddisfly larvae. Fly fishermen are familiar with these organisms, which inhabit the bottom of freshwater streams until the flies hatch.

Caddisflies build their tubes in the same way as P. californica, but with a much different glue — strands of silk that attach to the bits of sand, tying them all together. At some evolutionary point tens of millions of years ago the flies were related to silkworms, so the fact that they spin silk is not too surprising. “Except it’s a sticky, underwater silk,” Dr. Stewart said.

He is just beginning to characterize the silk and understand how the caddisflies produce it, but the eventual goal is the same as with the sandcastle worm.

“We want to try to mimic it someday soon, and spin fibers underwater,” he said. “Waterborne polymers underwater, which might have some medical application.”

A big concern with any synthetic glue, no matter how closely it mimics one from a living creature, is biocompatibility. “We might be able to solve the adhesion problems,” Dr. Messersmith said, “but then we confront the biological problems.”

There are medical superglues that do form strong bonds, he said, “but those materials are highly immunogenic.”

Dr. Stewart said that so far he has seen little inflammation in the rat studies, and little if any evidence of toxicity or inhibition of bone healing.

But he noted that since one goal would be to have the glue eventually degrade, some response by the body would seem to be necessary.

With a bone glue, for example, “you want it to degrade roughly at the same rate as the bone regrows,” he said. So in degradable versions of his synthetic polymer glues, Dr. Stewart actually adds back proteins that can be attacked and broken down by specialized cells.

“You wouldn’t want some plastic glue in your bones for the rest of your life,” he said.

Henry Fountain, New York Times

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Full article and photos: http://www.nytimes.com/2010/04/13/science/13adhesive.html

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A 6-foot monitor lizard discovered on Luzon Island in he Philippines

The number of lizard species in the world — by most counts, around 4,000 — has just increased by one, with the announcement of a new species found on Luzon island in the Philippines.

But this is not a reptile you’d want in a home terrarium. It’s a 6-foot monitor lizard, gray with a spectacular pattern of colorful dots and other markings on its scales.

How did a species of lizard the size of a human remain undetected all these centuries? The answer is it didn’t. “It’s only new to science,” said Rafe M. Brown, an assistant professor at the University of Kansas and senior author of a paper describing the new species, Varanus bitatawa, in Biology Letters.

Dr. Brown said the lizard, which has a diet consisting almost entirely of fruit, was known to native people in the forested northeastern coastal region of Luzon. “They eat it, and it’s in their vocabulary,” he said. It first came to the attention of scientists about 10 years ago through a photograph of a local hunter with one of the lizards slung over his back. But it was not until last summer that an adult specimen was obtained from a hunter by two Kansas graduate students, Luke J. Welton and Cameron D. Silar.

The lizard is distinct, both in appearance and genetically, from a lizard of similar size found in southeastern Luzon. Unforested river valleys between the two areas probably served as a barrier to allow the two species to diverge, Dr. Brown said.

It’s not known if the species is threatened, but conservation in general is a concern in the Philippines. Being so large and colorful, the lizard could inspire efforts that could protect other animals.

Henry Fountain, New York Times

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Full article and photo: http://www.nytimes.com/2010/04/13/science/13oblizard.html

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The first-ever photograph of the Santa Marta sabrewing.

The mountainous area around Santa Marta, on Colombia’s Caribbean coast, is a biological hotspot of sorts, filled with bird species that are found nowhere else.

“It’s just chock-full of these rare endemic birds,” said Michael Parr, vice president of American Bird Conservancy, which works to protect wild birds and their habitat in the Americas. Among the species found there is a hummingbird, the Santa Marta sabrewing.

Rare birds in isolated habitats can be a recipe for extinction, and while there had been a few unconfirmed sightings of the sabrewing in recent years, the bird’s existence had not been documented for decades. Until March 24, that is, when a researcher studying migratory birds, Laura Cárdenas, caught one in a mist net, banded it and took its picture before releasing it. It’s the first photograph ever of a Santa Marta sabrewing.

“She had a little bit of luck,” Mr. Parr said. “The bird just flew into the net, completely by chance.”

The photograph was taken in the El Dorado Preserve, 1,700 acres of land in the mountains that was purchased by the conservancy and other groups in 2006. More than 360 bird species have been found there, including the hummingbird and 10 others that are listed as threatened.

The eventual goal is to expand the reserve to about 7,000 acres in an area that has been badly deforested. “It’s the very best piece of remaining habitat,” Mr. Parr said.

The sighting shows that “the ecosystem is more intact than you might have feared,” he added.

Henry Fountain, New York Times

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Full article and photo: http://www.nytimes.com/2010/04/13/science/13obbird.html

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Laboratory Life

Here’s a problem: evolution never stops.

Imagine you’re a wild fruit fly, of the species Drosophila melanogaster. You’re happily feasting on some yeast that’s growing on rotting fruit when, whoomf, you get sucked into a bottle and taken to a laboratory. From now on, this is your home.

Life in a bottle — or cage — is different from life in the wild. In nature, for example, fruit flies reproduce throughout their adult lives. Often, in the laboratory, they do not: flies grown in bottles may only be allowed to reproduce for the first five or six days after emerging from the pupa. (Wild flies can live for more than 80 days.) In nature, flies choose their mates. Often, in the laboratory, they do not: they are often assigned to one, and that one may be a close relative. On top of that, the food is different; infectious diseases are rare; predators are absent.

In short, the pressures of daily life have been transformed — and traits that were an advantage Out There may no longer be so Inside. Similarly, traits that would have killed you in the wild may help you get along inside a bottle.

If, for example, older flies are never allowed to reproduce, the ability to lay eggs later in life becomes irrelevant, so there’s nothing to prevent the appearance of mutations that interfere with that ability. Indeed, if those mutations increase early fertility, they may even be favored: the most fecund young flies are likely to leave the most descendants.

Thus, the switch from the wild to the laboratory immediately alters the evolutionary trajectory of a population — and sure enough, within a few generations, laboratory-bred life-forms become noticeably different from their wild cousins.

Exactly what happens depends on how the organisms are kept — different rearing methods create different evolutionary forces. But in general, laboratory Drosophila melanogaster evolve shorter lifespans than wild flies; they become less able to cope with stresses like starvation or desiccation; and their pattern of fertility changes. As you’d expect, females reared in bottles evolve to be hugely fecund as young flies but much less so when they are older.

Also as you’d expect, laboratory evolution is not unique to Drosophila melanogaster. In the wasp Nasonia vitripennis, females descended from a long line of laboratory wasps evolve to be more prone to promiscuous sexual behavior than wild wasps. In the Mediterranean fruit fly, Ceratitis capitata, laboratory-reared females evolve to be less fussy about who they mate with, and male sexiness changes. Wild female medflies don’t find laboratory-reared males as attractive as they find wild males. Mexican fruit flies, Anastrepha ludens, have the same problem: laboratory males have evolved in such a way that they are less popular with wild females.

Mice show a host of changes, too. Compared to their wild relations, laboratory mice are typically bigger, more docile, reach sexual maturity earlier and die younger. Some of these changes can appear quickly: one study found that the ability to reproduce later in life declined within 10 generations of the mice being bred in the laboratory.

Intriguingly, laboratory mice also have longer telomeres than wild mice. (Telomeres are the segments of DNA at the ends of chromosomes; they are thought to play a role in aging and cancer.) Since no one is deliberately breeding mice for extra-long telomeres, this must arise as some consequence of laboratory life. But what?

That’s not clear. One possibility is that it’s due to inbreeding — for lab mice are often highly inbred. Consistent with this, one study of white-footed mice, Peromyscus leucopus, found that, when animals were forced to inbreed, telomeres lengthened substantially in fewer than 30 generations — although why this should be so is entirely mysterious.

All of which is fascinating. But does it matter?

That depends. For some scientific problems, the fact that laboratory life-forms evolve substantial differences from their wild relatives is irrelevant. For others, however, it matters a lot.

Let me give you two examples. Adaptation to the laboratory — or to captivity more generally — can make it much more difficult for organisms to thrive if they are later released to the wild. This has important implications for the conservation of endangered animals and for the control of pests. Captive breeding programs have been important tools for re-establishing wild populations of species such as the California condor; but not all programs are successful. Genetic changes in captivity may be one reason. Similarly, many pest control programs depend on the “sterile male technique,” whereby males are bred in the laboratory, sterilized, then released into nature to mate with wild females. For this to work, the wild females must find the laboratory males attractive. Changes in mating behavior like the ones I mentioned earlier can, therefore, quickly reduce the effectiveness of the approach.

A second area where laboratory evolution can be a serious problem is in the study of subjects like the evolution of aging, and the diseases associated with it. For example, the study of laboratory populations may give a misleading impression of how easy it is to extend lifespans: since laboratory organisms tend to have unnaturally short lifespans, discovering ways to make them live longer may not be especially informative. We may simply be reversing the unnatural shortening that we created in the first place, a view supported by the fact that selection to increase lifespan in laboratory populations often simply restores it to levels seen in the wild.

Such realizations have led an increasing number of scientists to argue that long-established laboratory populations are “suspect starting material” for understanding aging, and that comparisons with wild populations “support the pessimistic interpretation that laboratory-adapted stocks of rodents may be particularly inappropriate for the analysis of the genetic and physiological factors that regulate aging in mammals.”

For some subjects, it’s better to go wild.

Notes:

For an interesting overview of evolution in the laboratory, see Artamonova, V. S. and Makhrov, A. A. 2006. “Unintentional genetic processes in artificially maintained populations: proving the leading role of selection in evolution.” Russian Journal of Genetics 42: 234-246.

A large number of studies have found evidence of evolution to laboratory conditions. For Drosophila melanogaster, I drew, in part, on Sgrò, C. M. and Partridge, L. 2000. “Evolutionary responses of the life history of wild-caught Drosophila melanogaster to two standard methods of laboratory culture.” American Naturalist 156: 341-353. This paper shows how differences in laboratory rearing methods can affect evolutionary trajectories, and also shows how truncating the reproductive life of adult flies rapidly leads to flies evolving to reproduce more earlier; compared to wild flies, laboratory flies had shorter lives. For laboratory populations being “suspect starting material” for aging studies, see page 351 of this paper.

For the lifespan of wild flies compared to laboratory flies, see Linnen, C., Tatar, M. and Promislow, D. 2001. “Cultural artifacts: a comparison of senescence in natural, laboratory-adapted and artificially selected lines of Drosophila melanogaster.” Evolutionary Ecology Research 3: 877-888. These authors show that wild flies live longer than standard laboratory flies, and that lines of flies that have been bred specifically to have long lifespans do not live longer than wild flies.

For laboratory rearing leading to loss of resistance to desiccation and starvation, see Hoffmann, A. A. et al. 2001. “Rapid loss of stress resistance in Drosophila melanogaster under adaptation to laboratory culture.” Evolution 55: 436-438. For promiscuous laboratory wasps, see Burton-Chellew, M. N. et al. 2007. “Laboratory evolution of polyandry in the parasitoid wasp Nasonia vitripennis.” Animal Behaviour 74: 1147-1154.

For evolution in the mating behavior of laboratory populations of medflies, see Rodriguero, M. S. et al. 2002. “Sexual selection on multivariate phenotype in wild and mass-reared Ceratitis capitata (Diptera: Tephritidae).” Heredity 89: 480-487. For the same phenomenon in Mexican fruit flies, see Rull, J., Brunel, O. and Mendez, M. E. 2005. “Mass rearing history negatively affects mating success of male Anastrepha ludens (Diptera: Tephritidae) reared for sterile insect technique programs.” Journal of Economic Entomology 98: 1510-1516. These papers also discuss the problems that laboratory evolution pose for pest control. An additional analysis of this is provided by Hendrichs, J. et al. 2002. “Medfly areawide sterile insect technique programmes for prevention, suppression, or eradication: the importance of mating behavior studies.” Florida Entomologist 85: 1-13.

For an overview of evolutionary changes in laboratory mice, see Miller, R. A. et al. 2002. “Longer life spans and delayed maturation in wild-derived mice.” Experimental Biology and Medicine 227: 500-508. This paper shows that wild-caught mice live much longer than most laboratory mice, and reach sexual maturity later. These authors are also responsible for the “pessimistic interpretation” quotation; see page 507.

For the study showing that the ability to reproduce later in life can decline within 10 generations of laboratory residence, see Flurkey, K. et al. 2007. “PohnB6F1: a cross of wild and domestic mice that is a new model of extended female reproductive life span.” Journal of Gerontology, Biological Sciences 62A: 1187-1198.

For laboratory mice having weirdly long telomeres, see Hemann, M. T. and Greider, C. W. 2000. “Wild-derived inbred mouse strains have short telomeres.” Nucleic Acids Research 28: 4474-4478. For inbreeding producing long telomeres in white-footed mice, see Manning, E. L. et al. 2002. “Influences of inbreeding and genetics on telomere length in mice.” Mammalian Genome 13: 234-238.

For the possibility that evolution in captivity may pose a potential problem for captive breeding programs, see Woodworth, L. M. et al. 2002. “Rapid genetic deterioration in captive populations: causes and consequences.” Conservation Genetics 3: 277-288; and Williams, S. E. and Hoffman, E. A. 2009. “Minimizing genetic adaptation in captive breeding programs: a review.” Biological Conservation 142: 2388-2400.

The problem of laboratory mice in aging research has been discussed extensively by some authors. In addition to the papers I have already mentioned, see Harper, J. M. 2008. “Wild-derived mouse stocks: an underappreciated tool for aging research.” Age 30: 135-145; and Miller, R. A. et al. 1999. “Exotic mice as models for aging research: polemic and prospectus.” Neurobiology of Aging 20: 217-231.

Many thanks to Bret Weinstein for drawing my attention to the fact of long telomeres in laboratory mice, and for discussions about some of the implications this may have. Many thanks also to Nicholas Judson and Jonathan Swire for insights, comments and suggestions.

Olivia Judson, New York Times

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Full article: http://opinionator.blogs.nytimes.com/2010/04/13/laboratory-life/

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Researchers have gained new insights into the brain by decoding the genome of the zebra finch, a songbird whose males learn a single love song from their fathers that they repeat through life.

A team led by Wesley C. Warren and Richard K. Wilson at the Washington University School of Medicine in St. Louis decoded the bird’s genome at a cost of about $1 million, Dr. Warren said. That’s down from the $10 million needed several years ago to decode the chicken’s genome.

Some 50 laboratories around the world are studying the zebra finch, many in the hope of gleaning clues about how human language is learned. Like people and a few other species, the finch can imitate a sound it hears.

The mechanisms of this vocal learning seem to be quite similar in birds and people, from the level of the brain’s anatomy down to specific genes. People with mutations in a gene called FOXP2 have several kinds of speech defects, and researchers have found songbirds cannot sing when their version of the gene is disrupted. With the zebra finch’s genome in hand, researchers have learned that a surprising number of the bird’s genes are involved in singing and listening to the songs of other zebra finches. Some 800 genes become either more or less active in the zebra finch’s neurons during singing, the researchers say in the current issue of Nature.

“Now that we have taken the lid off the cells we see they are pumping out all this transcriptional energy,” said David F. Clayton, a songbird biologist at the University of Illinois and co-author of the report. This finding undercuts the common view of the brain as relatively stable in terms of genetic activity.

While the bird is listening to a song, the genes in its neurons are producing a large number of transcripts, or copies of genes. But these transcripts don’t result in the cells producing proteins in the usual way. Instead they seem to modulate the activity of other genes involved in listening. “This is the first demonstration that these non-coding transcripts are robustly involved and activated in real time,” Dr. Clayton said.

Another co-author, Erich Jarvis, a songbird biologist at Duke University, said theirs was one of the first studies to show this high level of gene activity and regulation occurring during a natural behavior. The biological basis of learning is usually studied in rats or mice set to master artificial tasks. With the songbird, researchers have a way of following a rich natural behavior.

“A long-range goal is to understand the genetic contribution to learning a song, and to find out why the zebra finch learns one song and never changes while others like mocking birds can learn different songs,” Dr. Clayton said.

Birds have a genome of about one billion units of DNA, one-third the size of humans’, yet possess about the same number of genes, since less is taken up with repetitive DNA sequences.

The sequence of the zebra finch genome will assist other biologists who study the bird. Besides vocal learning, they hope to understand the genetic basis of other aspects of the bird’s behavior, like its parental care, territoriality and selection of mates.

Nicholas Wade, New York Times

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Full article: http://www.nytimes.com/2010/04/06/science/06bird.html

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The first fossil ant from Africa, found in amber dating back 95 million years, challenges a previously held theory that ants originated in North America or East Asia.

The finding is part of a larger study published in the Proceedings of the National Academy of Sciences identifying 28 fossilized insects, one spider and one mite, as well as a variety of flora all trapped in amber from Ethiopia.

The insects, the oldest that have been identified in Africa, are from the Cretaceous. There are also numerous fungi, ferns and spores that were previously unknown to paleontologists.

Until now, paleontologists had assumed that ants originated in North America or South Asia, because the only known fossils were from these regions, said Alexander Schmidt, the paper’s lead author and a biologist at the University of Göttingen in Germany.

He and his colleagues are convinced that further analysis will reveal more about the evolution of the ants and how the Ethiopian ant is biologically related to Cretaceous ants of the Northern Hemisphere.

The paper is a culmination of five years of study by 20 researchers from seven countries, including specialists in dating the amber, and experts in different insects and flora.

“This was a really interdisciplinary project and it was our intent to produce a holistic study,” he said.

The samples are primarily housed in Berlin and Vienna, though some are also in the American Museum of Natural History in New York.

Syndhia N. Baanou, New York Times

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Full article: http://www.nytimes.com/2010/04/06/science/06obamber.html

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Can Animals Be Gay?

The Laysan albatross is a downy seabird with a seven-foot wingspan and a notched, pale yellow beak. Every November, a small colony of albatrosses assembles at a place called Kaena Point, overlooking the Pacific at the foot of a volcanic range, on the northwestern tip of Oahu, Hawaii. Each bird has spent the past six months in solitude, ranging over open water as far north as Alaska, and has come back to the breeding ground to reunite with its mate. Albatrosses can live to be 60 or 70 years old and typically mate with the same bird every year, for life. Their “divorce rate,” as biologists term it, is among the lowest of any bird.

When I visited Kaena Point in November, the first birds were just returning, and they spent a lot of their time gliding and jackknifing in the wind a few feet overhead or plopped like cushions in the sand. There are about 120 breeding albatrosses in the colony, and gradually, each will arrive and feel out the crowd for the one other particular albatross it has been waiting to have sex with again. At any given moment in the days before Thanksgiving, some birds may be just turning up while others sit there killing time. It feels like an airport baggage-claim area.

Once together, pairs will copulate and collaboratively incubate a single egg for 65 days. They take shifts: one bird has to sit at the nest while the other flaps off to fish and eat for weeks at a time. Couples preen each other’s feathers and engage in elaborate mating behaviors and displays. “Like when you’re in a couple,” Marlene Zuk, a biologist who has visited the colony, explained to me. “All those sickening things that couples do that gross out everyone else but the two people in the couple? . . . Birds have the same thing.” I often saw pairs sitting belly to belly, arching their necks and nuzzling together their heads to form a kind of heart shape. Speaking on Oahu a few years ago as first lady, Laura Bush praised Laysan albatross couples for making lifelong commitments to one another. Lindsay C. Young, a biologist who studies the Kaena Point colony, told me: “They were supposed to be icons of monogamy: one male and one female. But I wouldn’t assume that what you’re looking at is a male and a female.”

Young has been researching the albatrosses on Oahu since 2003; the colony was the focus of her doctoral dissertation at the University of Hawaii, Manoa, which she completed last spring. (She now works on conservation projects as a biologist for hire.) In the course of her doctoral work, Young and a colleague discovered, almost incidentally, that a third of the pairs at Kaena Point actually consisted of two female birds, not one male and one female. Laysan albatrosses are one of countless species in which the two sexes look basically identical. It turned out that many of the female-female pairs, at Kaena Point and at a colony that Young’s colleague studied on Kauai, had been together for 4, 8 or even 19 years — as far back as the biologists’ data went, in some cases. The female-female pairs had been incubating eggs together, rearing chicks and just generally passing under everybody’s nose for what you might call “straight” couples.

Young would never use the phrase “straight couples.” And she is adamantly against calling the other birds “lesbians” too. For one thing, the same-sex pairs appear to do everything male-female pairs do except have sex, and Young isn’t really sure, or comfortable judging, whether that technically qualifies them as lesbians or not. But moreover, the whole question is meaningless to her; it has nothing to do with her research. “ ‘Lesbian,’ ” she told me, “is a human term,” and Young — a diligent and cautious scientist, just beginning to make a name in her field — is devoted to using the most aseptic language possible and resisting any tinge of anthropomorphism. “The study is about albatross,” she told me firmly. “The study is not about humans.” Often, she seemed to be mentally peer-reviewing her words before speaking.

A discovery like Young’s can disorient a wildlife biologist in the most thrilling way — if he or she takes it seriously, which has traditionally not been the case. Various forms of same-sex sexual activity have been recorded in more than 450 different species of animals by now, from flamingos to bison to beetles to guppies to warthogs. A female koala might force another female against a tree and mount her, while throwing back her head and releasing what one scientist described as “exhalated belchlike sounds.” Male Amazon River dolphins have been known to penetrate each other in the blowhole. Within most species, homosexual sex has been documented only sporadically, and there appear to be few cases of individual animals who engage in it exclusively. For more than a century, this kind of observation was usually tacked onto scientific papers as a curiosity, if it was reported at all, and not pursued as a legitimate research subject. Biologists tried to explain away what they’d seen, or dismissed it as theoretically meaningless — an isolated glitch in an otherwise elegant Darwinian universe where every facet of an animal’s behavior is geared toward reproducing. One primatologist speculated that the real reason two male orangutans were fellating each other was nutritional.

In recent years though, more biologists have been looking objectively at same-sex sexuality in animals — approaching it as real science. For Young, the existence of so many female-female albatross pairs disproved assumptions that she didn’t even realize she’d been making and, in the process, raised a chain of progressively more complicated questions. One of the prickliest, it seemed, was how a scientist is even supposed to talk about any of this, given how eager the rest of us have been to twist the sex lives of animals into allegories of our own. “This colony is literally the largest proportion of — I don’t know what the correct term is: ‘homosexual animals’? — in the world,” Young told me. “Which I’m sure some people think is a great thing, and others might think is not.”

It was a guarded understatement. Two years ago, Young decided to write a short paper with two colleagues on the female-female albatross pairs. “We were pretty careful in the original article to plainly and simply report what we found,” she said. “It’s definitely a little bit of a tricky subject, and one you want to be gentle on.” But the journal that published the paper, Biology Letters, sent out a press release a few days after the California Supreme Court legalized gay marriage. At 6 the next morning, a Fox News reporter called Young on her cellphone. The resulting story joined others, including one in this paper, and as the news ricocheted around the Internet, a stampede of online commenters alternately celebrated Young’s findings as a clear call for equality or denigrated them as “pure propaganda and selective science at its dumbest” and “an effort to humanize animals or devolve humans to the level of animals or to further an agenda.” Many pointed out that animals also rape or eat their young; was America going to tolerate that too, just because it’s “natural”?

A Denver-based publication for gay parents welcomed any and all new readers from “the extensive lesbian albatross parent community.” The conservative Oklahoma senator Tom Coburn highlighted Young’s paper on his Web site, under the heading “Your Tax Dollars at Work,” even though her study of the female-female pairs was not actually federally financed. Stephen Colbert warned on Comedy Central that “albatresbians” were threatening American family values with their “Sappho-avian agenda.” A gay rights advocate e-mailed Young, asking her to fly a rainbow flag above each female-female nest, to identify them and show solidarity. Even now, the first thing everyone wants to know from Young — sometimes the only thing — is, what do these lesbian albatrosses say about us?

“I don’t answer that question,” she told me.

A FEMALE LAYSAN albatross is physically capable of laying only one egg per year — that’s just how it’s built. Nevertheless, since as early as 1919, biologists have periodically found nests of albatrosses (and similar species of birds) with two eggs inside them, or with a second egg just outside, as if it had rolled out. (This will inevitably happen; there’s simply not enough room in the nest for two eggs and one Laysan albatross.) Scientists have a term for the phenomenon of extra eggs in a nest: a “supernormal clutch.” But in the case of the albatross, they never had a watertight explanation.

A female pair at a Laysan albatross colony in Kaena Point, Hawaii.

In the early 1960s, one ornithologist tried to put the whole cumbersome mystery to rest by asserting that some of those female birds must simply be able to lay multiple eggs. The claim was apparently based on sketchy data, but supernormal clutches were so rare that it was hard to rack up enough observations to disprove the hypothesis. Real progress was finally made in 1968, when Harvey Fisher, a dean of midcentury albatross science, reported on seven years of daily observations made at 3,440 different nests on the Midway atoll in the middle of the Pacific. Fisher concluded that “two eggs in a nest are an indication that two females used the nest, although at different times.” He was describing “egg dumping,” whereby, for example, an inexperienced female accidentally lays her egg in the wrong nest. From then on, egg dumping was a default explanation for supernormal clutches in albatrosses. After all, Fisher had also declared that “promiscuity, polygamy and polyandry are unknown in this species.” Lesbianism apparently never occurred to anyone — even enough to be cursorily dismissed. As Brenda Zaun recently told me, “It never dawned on anyone to sex the birds.”

Zaun, a biologist with the U.S. Fish and Wildlife Service, was studying a Laysan colony on Kauai 40 years after Fisher’s publication. She realized that certain nests there seemed to wind up with two eggs in them year after year; the distribution of the supernormal clutches wasn’t random, as it would presumably be if it were caused exclusively by egg dumping. On a hunch, Zaun pulled feathers from a sample of the breeding pairs associated with two-egg nests and sent them to Lindsay Young, asking her to draw DNA from the feathers and genetically determine the sexes of those birds in her lab. When the results showed that every bird was female, Young figured she’d messed up. So she did it again — and got the same result. Then she genetically sexed every bird at Kaena Point. “Where it wasn’t totally clear, or I worried that maybe I mixed up the sample, I actually went back into the field and took new blood samples to do it again,” Young told me. In the end, she genetically sexed the birds in her lab four times, just to be sure. She found that 39 of the 125 nests at Kaena Point since 2004 belonged to female-female pairs, including more than 20 nests in which she’d never noticed a supernormal clutch. It seemed that certain females were somehow finding opportunities to quickly copulate with males but incubating their eggs — and doing everything else an albatross does while at the colony — with other females.

Young gave a talk about these findings at an international meeting of Pacific-seabird researchers. “There was a lot of murmuring in the room,” she remembers. “Then, afterward, people were coming up to me and saying: ‘We see supernormal clutches all the time. We assumed it was a male and a female.’ And I’d say: ‘Yeah? Well, you might want to look into that.’ ” Recently, journals have asked her to confidentially peer-review new papers about other species, describing similar discoveries. “I can’t say which species,” she explains, “but my guess is, in the next year, we’re going to see a lot more examples of this.”

It may seem surprising that scientists sometimes don’t know the true sexes of the animals they spend their careers studying — that they can be tripped up in some “Tootsie” -like farce for so long. But it’s easy to underestimate the pandemonium that they’re struggling to interpret in the wild. Often, biologists are forced to assign sexes to animals by watching what they do when they mate. When one albatross or boar or cricket rears up and mounts a second, it would seem to be advertising the genders of both. Unless, of course, that’s not the situation at all.

“There is still an overall presumption of heterosexuality,” the biologist Bruce Bagemihl told me. “Individuals, populations or species are considered to be entirely heterosexual until proven otherwise.” While this may sound like a reasonable starting point, Bagemihl calls it a “heterosexist bias” and has shown it to be a significant roadblock to understanding the diversity of what animals actually do. In 1999, Baghemihl published “Biological Exuberance,” a book that pulled together a colossal amount of previous piecemeal research and showed how biologists’ biases had marginalized animal homosexuality for the last 150 years — sometimes innocently enough, sometimes in an eruption of anthropomorphic disgust. Courtship behaviors between two animals of the same sex were persistently described in the literature as “mock” or “pseudo” courtship — or just “practice.” Homosexual sex between ostriches was interpreted by one scientist as “a nuisance” that “goes on and on.” One man, studying Mazarine Blue butterflies in Morocco in 1987, regretted having to report “the lurid details of declining moral standards and of horrific sexual offenses” which are “all too often packed” into national newspapers. And a bighorn-sheep biologist confessed in his memoir, “I still cringe at the memory of seeing old D-ram mount S-ram repeatedly.” To think, he wrote, “of those magnificent beasts as ‘queers’ — Oh, God!”

“What Bagemihl’s book really did,” the Canadian primatologist and evolutionary psychologist Paul Vasey says, “is raise people’s awareness around the fact that this occurs in quote-unquote nature — in animals. And that it can be studied in a serious, scholarly way.” But studying it seriously means resolving a conundrum. At the heart of evolutionary biology, since Darwin, has been the idea that any genetic traits and behaviors that outfit an animal with an advantage — that help the animal make lots of offspring — will remain in a species, while ones that don’t will vanish. In short, evolution gradually optimizes every animal toward a single goal: passing on its genes. The Yale ornithologist Richard Prum told me: “Our field is a lot like economics: we have a core of theory, like free-market theory, where we have the invisible hand of the market creating order — all commodities attain exactly the price they’re worth. Homosexuality is a tough case, because it appears to violate that central tenet, that all of sexual behavior is about reproduction. The question is, why would anyone invest in sexual behavior that isn’t reproductive?” –— much less a behavior that looks to be starkly counterproductive. Moreover, if animals carrying the genes associated with it are less likely to reproduce, how has that behavior managed to stick around?

Given this big umbrella of theory, the very existence of homosexual behavior in animals can feel a little like impenetrable nonsense, something a researcher could spend years banging his or her head against the wall deliberating. The difficulty of that challenge, more than any implicit or explicit homophobia, may be why past biologists skirted the subject.

IN THE LAST DECADE, however, Paul Vasey and others have begun developing new hypotheses based on actual, prolonged observation of different animals, deciphering the ways given homosexual behaviors may have evolved and the evolutionary role they might play within the context of individual species. Different ideas are emerging about how these behaviors could fit within that traditional Darwinian framework, including seeing them as conferring reproductive advantages in roundabout ways. Male dung flies, for example, appear to mount other males to tire them out, knocking them out of competition for available females. Researchers speculate that young male bottlenose dolphins mount one another simply to establish trust and form bonds — but those bonds actually turn out to be critical to reproduction, since when males mature, they work in groups to cooperatively gain access to females.

These ideas generally aim to explain only particular behaviors in a particular species. So far, the only real conclusion this relatively small body of literature seems to point to, collectively, is a kind of deflating, meta-conclusion: a single explanation of homosexual behavior in animals may not be possible, because thinking of “homosexual behavior in animals” as a single scientific subject might not make much sense. “Biologists want to build these unified theories to explain everything they see,” Vasey told me. So do journalists, he added — all people, really. “But none of this lends itself to a linear story. My take on it is that homosexual behavior is not a uniform phenomenon. Having one unifying body of theory that explains why it’s happening in all these different species might be a chimera.”

The point of heterosexual sex, Vasey said, no matter what kind of animal is doing it, is primarily reproduction. But that shouldn’t trick us into thinking that homosexual behavior has some equivalent, organizing purpose — that the two are tidy opposites. “All this homosexual behavior isn’t tied together by that sort of primary function,” Vasey said. Even what the same-sex animals are doing varies tremendously from species to species. But we’re quick to conceive of that great range of activities in the way it most handily tracks to our anthropomorphic point of view: put crassly, all those different animals just seem to be doing gay sex stuff with one another. As the biologist Marlene Zuk explains, we are hard-wired to read all animal behavior as “some version of the way people do things” and animals as “blurred, imperfect copies of humans.”

When I visited Zuk at her lab at the University of California at Riverside last December, an online video clip of an octopus carrying a coconut shell around the seafloor, and periodically hiding under it, was starting to go viral. For a few days, people everywhere were flipping out about how intelligent and wily this octopus was. Not Zuk, though. “Oh, spare me,” she said. To us, Zuk explained, that octopus’s behavior reads as proof that “octopuses are at one with humans” because it just happens to look like something we do — how a toddler plays peekaboo under a blanket, say, or a bandit ducks into an alleyway dumpster to avoid the cops. But the octopus doesn’t know that. Nor is it doing something so uncommon in the animal world. Zuk explained that caddis-fly larvae collect rocks and loom them together into intricate shelters. “But for some reason we don’t think that’s cool,” she said, “because the caddis-fly larvae don’t have big eyes like us.”

Something similar may be happening with what we perceive to be homosexual sex in an array of animal species: we may be grouping together a big grab bag of behaviors based on only a superficial similarity. Within the logic of each species, or group of species, many of these behaviors appear to have their own causes and consequences — their own evolutionary meanings, so to speak. The Stanford biologist Joan Roughgarden told me to think of all these animals as “multitasking” with their private parts.

It’s also possible that some homosexual behaviors don’t provide a conventional evolutionary advantage; but neither do they upend everything we know about biology. For the last 15 years, for example, Paul Vasey has been studying Japanese macaques, a species of two-and-a-half-foot-tall, pink-faced monkey. He has looked almost exclusively at why female macaques mount one another during the mating season. Vasey now says he is on to the answer: “It isn’t functional,” he told me; the behavior has no discernible purpose, adaptationally speaking. Instead, it’s a byproduct of a behavior that does, and the supposedly streamlining force of evolution just never flushed that byproduct from the gene pool. Female macaques regularly mount males too, Vasey explained, probably to focus their attention and reinforce their bond as mates. The females are physically capable of mounting any gender of macaque. They’ve just never developed an instinct to limit themselves to one. “Evolution doesn’t create perfect adaptations,” Vasey said. As Zuk put it, “There’s a lot of slop in the system — which,” she was sure to add, “is not the same as saying homosexuality is a mistake.”

ABOUT TWO DOZEN birds were knocking around when Lindsay Young and I arrived at Kaena Point one afternoon. Young dished about a few of them — “Her mate didn’t show up last year”; “God, this one’s annoying” — as they waddled by. Laysan albatrosses are not nearly as graceful on land as they are in the air; even they seem surprised by the size of their feet. (Later that week, at a nearby resort, I would recognize their gait while watching an out-of-shape snorkeler toddle back to his beach towel in rented flippers.) “I’m just writing down who’s here,” Young said, reading the numbers on the birds’ leg bands and marking them on her clipboard. After trying and failing to get a clear view of one bird’s leg with binoculars, she finally just walked to within a few feet of the animal and leaned over to look.

This is the luxury of studying Laysan albatrosses. Having evolved with no natural predators, the birds have no fight-or-flight instinct — you can basically go right up to one and grab it. In fact, Young did just this a short while later, slinking up to a male on all fours, sweeping it in by its flank and, in one expert motion, straightjacketing the wings under one arm and clamping the beak shut in her other hand. Then, she walked over and handed the thing to me; she needed to take an expensive tracking device off the bird’s ankle. “Sorry, but it’s like watching a thousand-dollar bill fly around,” she said. She took some pliers from her backpack to twist off the anklet and, as I stood bear-hugging the albatross, she added: “They have a nice smell. It’s a little musty.”

Young and Marlene Zuk are now applying for a 10-year National Science Foundation grant to continue studying the female albatross pairs. One of the first questions they want to answer is how these birds are winding up with fertilized eggs. Typically, albatrosses fend off birds who aren’t their mates. So Young has been trying to determine if males who arrive back at the colony before their own partners do are forcing themselves on these females or whether these females are somehow “soliciting” the males for sex. She was staking out Kaena Point on a daily basis, trying to watch these illicit copulations unfold for herself. This was Young’s third year; so far, she’d only managed to see it happen twice.

Young and I ambled around for half an hour, maybe more. Then she pointed and, in a monotone, said, “So, that’s a female-female pair.” We crouched and watched the two birds, numbers 169 and 983. They sat under a spindly, native Hawaiian naio bush. They made baa sounds at each other. After a while, Young and I got up.

Another hour passed. (Usually, Young brings along a camping chair.) Occasionally, albatrosses danced in groups of two or three, raising their necks, groaning like vibrating cellphones, clacking their beaks or stomping. But most of the time, they didn’t do much at all. “I’ve spent a lot of my career watching animals not have sex,” Zuk later told me.

Homosexual activity is often observed in animal populations with a shortage of one sex — in the wild but more frequently at zoos. Some biologists anthropomorphically call this “the prisoner effect.” That’s basically the situation at Kaena Point: there are fewer male albatrosses than females (although not every male albatross has a mate). Because it takes two albatrosses to incubate an egg, switching on and off at the nest, a female that can’t find a male (or maybe, Young says, who can’t find “a good-enough male”) has no chance of producing a chick and passing on her genes. Quickly mating with an otherwise-committed male, then pairing with another single female to incubate the egg, is a way to raise those odds.

Still, pairing off with another female creates its own problems: nearly every female lays an egg in November whether she has managed to get it fertilized or not, and the small, craterlike nests that albatross pairs build in the dirt can accommodate only one egg and one bird. So Young was also trying to figure out how a female-female pair decides which of its two eggs to incubate and which to chuck out of the nest — if the birds are deciding at all, and not just knocking one egg out accidentally. From a strict Darwinian perspective, Young told me, “it doesn’t pay for one bird to incubate the other’s egg unless her partner is going to let her egg be incubated the following year.” But presumably, neither female bird knows whether an egg is hers or the other bird’s, much less whether it’s fertilized or not. A Laysan albatross just knows to sit on whatever’s under it. “They’ll incubate anything — I have a photo of one incubating a volleyball,” Young said.

And these were only preambles to more questions. With the male of an albatross pair replaced by another female, every step of the species’ normal, well-honed process for fledging a chick seemed suddenly to present a fresh dilemma. Ultimately, either the rules of albatrossdom were breaking down and the lesbian couples were booting up some alternate suite of behaviors, governed by its own set of rules, or else science had never thoroughly understood the rules of albatrossdom to begin with. And that’s the whole point, for Young: it’s the complexity and apparent flexibility of the species that fascinates her — the puzzle those female-female pairs create at Kaena Point just by existing. She’s not trying to explain homosexual behavior. She’s trying to explain the albatross. And that’s why the rest of the world’s politicized reaction to her work caught her by surprise.

Many people who contacted Young after the publication of her first albatross paper assumed she was a lesbian. She is not. Young’s husband, a biological consultant, was actually an author of the paper, along with Brenda Zaun (who is also not gay, for what it’s worth). Young found the assumption offensive — not because she was being mistaken for gay, but because she was being mistaken for a bad scientist; these people seemed to presume that her research was compromised by a personal agenda. Still, some of the biologists doing the most incisive work on animal homosexuality are in fact gay. Several people I spoke to told me their own sexual identities either helped spur or maintain their interest in the topic; Bruce Bagemihl argued that gay and lesbian people are “often better equipped to detect heterosexist bias when investigating the subject simply because we encounter it so frequently in our everyday lives.” With a laugh, Paul Vasey told me, “People automatically assume I’m gay.” He is gay, he added, but that fact didn’t seem to detract from his amusement.

IN RETROSPECT, the big, sloshing stew of anthropomorphic analyses that Young’s paper provoked in the culture couldn’t have been less surprising. For whatever reason, we’re prone to seeing animals — especially animals that appear to be gay — as reflections, models and foils of ourselves; we’re extraordinarily, and sometimes irrationally, invested in them.

Only a few months before I visited Kaena Point, two penguins at the San Francisco Zoo became the latest in a tradition of captive same-sex penguin couples making global headlines. After six years together — in which the two birds even fostered a son, named Chuck Norris — the penguins split up when one of the males ran off with a female named Linda. The zoo’s penguin keeper, Anthony Brown, told me he received angry e-mail, accusing him of separating the pair for political reasons. “Penguins make their own decisions here at the San Francisco Zoo,” Brown assured me. And while he stressed that there is no scientific way of determining if animals are “gay,” because the word connotes a sexual orientation, not just a behavior, he also noted that, being the San Francisco Zoo, “there’s definitely a lot of opinion here, internally, that we give in and call the penguins gay.” Another male-male penguin couple who fostered a chick at the Central Park Zoo was subsequently immortalized in 2005 in the illustrated children’s book “And Tango Makes Three.” According to the American Library Association, there have been more requests for libraries to ban “And Tango Makes Three” every year than any other book in the country, three years running.

What animals do — what’s perceived to be “natural” — seems to carry a strange moral potency: it’s out there, irrefutably, as either a validation or a denunciation of our own behavior, depending on how you happen to feel about homosexuality and about nature. During the Victorian era, observations of same-sex behavior in swans and insects were held up as evidence against the morality of homosexuality in humans, since at the dawn of industrialism and Darwinism, people were invested in seeing themselves as more civilized than the “lower animals.” Robert Mugabe and the Nazis have employed the same reasoning, as did the 1970s anti-gay crusader Anita Bryant, who, Bruce Bagemihl notes, claimed in an interview that “even barnyard animals don’t do what homosexuals do” and was unmoved when the interviewer pointed out what actually happens in barnyards. On the other hand, an Australian drag queen known as Dr. Gertrude Glossip has used Bagemihl’s book to create a celebratory, interpretive gay animal tour of the Adelaide zoo, marketed to gay and lesbian tourists. The book has also been cited in a 2003 Supreme Court case that overturned a Texas state ban on sodomy and, similarly, in a legislative debate on the floor of the British Parliament.

James Essex, director of the Lesbian, Gay, Bisexual and Transgender Project at the American Civil Liberties Union, told me he has never incorporated facts about animal behavior into a legal argument about the rights of human beings. It’s totally beside the point, he said; people should not be discriminated against regardless of what animals do. (In her book, “Sexual Selections,” Marlene Zuk writes, “People need to be able to make decisions about their lives without worrying about keeping up with the bonobos.”) That being said, Essex told me, polls show that Americans are more likely to discriminate against gays and lesbians if they think homosexuality is “a choice.” “It shouldn’t be the basis of a moral judgment,” he said. But sometimes it is, and gay animals are compelling evidence that being gay isn’t a choice at all. In fact, Essex remembers reading a brief mention of animal homosexual behavior during an anthropology class in college in the mid-’80s. “And as a closeted guy, it made a difference to me,” he told me. He remembers thinking: “Oh, hey, this is quote-unquote natural. This is normal. This is part of the normal spectrum of humanity — or life.”

But later in our conversation, Essex paused and stayed silent for a while. He was thinking like a lawyer again now, and found a hole in that line of reasoning. “I guess, some of these animals could actually be quote-unquote making a choice,” he said. How could we, as humans, ever know? “Huh,” he said. “I’m just stopping to think that through. I’m not quite sure what to do with that.” Essex had stumbled right back into what he originally identified as the underlying problem. Those wanting to discriminate against gays and lesbians may have roped the rest of us into an argument over what’s “natural” just by asserting for so long that homosexuality is not. But affixing any importance to the question of whether something is natural or unnatural is a red herring; it’s impossible to pin down what those words mean even in a purely scientific context. (Zuk notes that animals don’t drive cars or watch movies, and no one calls those activities “unnatural.”) In the end, there’s just no coherent debate there to have. Animal research demonstrating the supposed “naturalness” of homosexuality has typically been embraced by gay rights activists and has put their opponents on the defensive. At the same time, research interpreted — or, maybe more often, misinterpreted — to be close to pinpointing that naturalness in a specific “gay gene” can make people on both sides anxious in a totally different way.

In 2007, for instance, the University of Illinois neurobiologist David Featherstone and several colleagues, while searching for new drug treatments for Lou Gehrig’s disease, happened upon a discovery: a specific protein mutation in the brain of male fruit flies made the flies try to have sex with other males. What the mutation did, more specifically, was tweak the fruit flies’ sense of smell, making them attracted to male pheromones — mounting other males was the end result. To Featherstone, how fruit flies smell doesn’t seem to have anything to do with human sexuality. “We didn’t think about the societal implications — we’re just a bunch of dorky biologists,” he told me recently. Still, after publishing a paper describing this mutation, he received a flood of phone calls and e-mail messages presuming that he could, and would, translate this new knowledge into a way of changing people’s sexual orientations. One e-mail message compared him with Dr. Josef Mengele, noting “the direct line that leads from studies like this to compulsory eradication of gay sexuality . . . whether [by] burnings at the stake or injections with chemical suppressants. You,” the writer added, “just placed a log on the pyre.” (Earlier that year, PETA and the former tennis star Martina Navratilova, among others, were waging similar attacks on a scientific study of gay sheep, presuming it was a precursor to developing a “treatment” for shutting off homosexuality in human fetuses.)

Still, many people who contacted Featherstone were actually grateful — for the same, baseless prospect. Some confessed struggling with feelings for members of the same sex and explained to him, very disarmingly, the anguish they’d been living with and the hope his fruit-fly study finally offered them. There were poignant phone calls from parents, concerned about their gay children. “I felt bad in a way,” Featherstone told me. It was hard not to be moved, and he would try to explain the implications of his research, or lack thereof, politely. “But there’s also this liberal, modern side of me that’s like: ‘Take it easy, lady. Let your son be your son.’ ”

Not long ago, more than two years after the publication of the fruit-fly paper, a woman wrote to Featherstone about her college-aged daughter. The daughter couldn’t shake an attraction to other girls but honestly felt she’d never be able to bring herself to accept it either. She was now contemplating suicide. “She feels that she is losing herself,” the mother wrote, “that sweet, innocent light that is within her.” Like many who reached out to Featherstone, the woman and her daughter seemed to take for granted that homosexuality was inborn — natural. Otherwise, the situation wouldn’t feel so torturously unfair. The mother begged Featherstone to rethink his unwillingness to turn his fruit-fly research into a treatment. “We all deserve a choice,” she wrote.

GRASPING FOR PARALLELS with animals can create emotional truths, though it usually results in slushy logic. It’s naïve to slap conclusions about a given species directly onto humans.

But it’s disingenuous to ignore the possibility of any connection. “A lot of zoologists are suspicious, I think, of applying the same evolutionary principles to humans that they apply to animals,” Paul Vasey, the Japanese-macaque researcher, told me. There’s an understandable tendency among some scientists to play down those links to stave off ideological misreading and controversy. “But broadly speaking, research on animals can inform research on humans,” Vasey says. What we learn about one species can expand or reorient our approach to others; a well-supported finding about one animal’s behavior can generate new hypotheses worth testing in another. “My research on Japanese macaques might influence how someone conducts their research on octopus, or their research on moose. Or their research on humans,” he said. In fact, it has influenced Vasey’s own research on humans.

Since 2003, in addition to his investigation of female-female macaque sex, Vasey has also been studying a particular group of men in Samoa. “Westerners would consider them the equivalent of gay guys, I guess,” he told me — they’re attracted exclusively to other men. But they’re not considered gay in Samoa. Instead, these men make up a third gender in Samoan culture, not men or women, called fa’afafine. (Vasey warned me that mislabeling the fa’afafine “gay” or “homosexual” in this article would jeopardize his ability to work with them in the future: while there’s no stigma attached to being fa’afafine in Samoan culture, homosexuality is seen as different and often repugnant, even by some fa’afafine.)

In a paper published earlier this year, Vasey and one of his graduate students at the University of Lethbridge, Doug P. VanderLaan, report that fa’afafine are markedly more willing to help raise their nieces and nephews than typical Samoan uncles: they’re more willing to baby-sit, help pay school and medical expenses and so on. Furthermore, this heightened altruism and affection is focused only on the fa’afafine’s nieces and nephews. They don’t just love kids in general. They are a kind of superuncle. This offers support for a hypothesis that has been toyed around with speculatively since the ’70s, when E. O. Wilson raised it: If a key perspective of evolutionary biology urges us to understand homosexuality in any species as a beneficial adaptation — if the point of life is to pass on one’s genes — then maybe the role of gay individuals is to somehow help their family members generate more offspring. Those family members will, after all, share a lot of the same genes.

Vasey and VanderLaan have also shown that mothers of fa’afafine have more kids than other Samoan women. And this fact supports a separate, existing hypothesis: maybe there’s a collection of genes that, when expressed in a male, make him gay but when expressed in a woman, make her more fertile. Like Wilson’s theory, this idea was also meant to explain how homosexuality is maintained in a species and not pushed out by the invisible hand of Darwinian evolution. But unlike Wilson’s hypothesis, it doesn’t try to find a sneaky way to explain homosexuality as an evolutionary adaptation; instead, it imagines homosexuality as a byproduct of an adaptation. It’s not too different from how Vasey explains why his female macaques insistently mount one another.

“What we’re finding in Samoa now,” Vasey told me, “is that it’s not an either-or.” Neither of the two hypotheses, on its own, can neatly explain the existence, or evolutionary contribution, of fa’afafine. “But when you put the two together,” he said, “the situation becomes a whole lot more nuanced.” It’s significant that Vasey began his work in Samoa only after he’d gotten to the crux of the macaque situation. “The Japanese macaques,” he told me, “in terms of my personal development, they raised my awareness of the possibility that homosexual behavior might not be an adaptation. I was more likely to put the two hypotheses together because I was just more sensitive, I guess, to the reality that the world . . . is organized so that adaptations and byproducts of adaptations coexist and hinge and impinge on each other. Humans are just another species.”

Vasey and VanderLaan’s work in Samoa doesn’t come close to settling theoretical questions about homosexuality. But unlike many biologists I spoke to, Vasey still seemed at ease discussing the speculative and even philosophical ties between animal and human sexuality. He’s not concerned with how foolishly or maliciously his work might be misread. “If somebody wanted to make something out of it, they could,” Vasey told me, “but they’d just look like some kind of misinformed hillbilly.”

Thus far, interpretations of his latest paper on the fa’afafine have been wildly contradictory but all equally overconfident. “New Gay Study Will Make Anti-Gay Activists Cry Uncle,” one blog headline read. Another claimed, “Darwinian Fundamentalists Desperate to Rationalize Homosexuality,” and cleared the way for a commenter to somehow bemoan Vasey’s findings as “justification” for gay men “to sexually abuse their nephews.”

“THERE’S TWO mating right there,” Lindsay Young called out.

They were right below her, 10 yards away on a flat, vegetated ridge. It was late afternoon. One albatross lay on its stomach, wobbling with its wings pulled back — the way penguins slide over ice — while a second stood upright behind it, fat rippling down its telescoping neck, as it pumped its pelvis. “That looks pretty standard,” Young said.

The birds carried on for a while. Then the male shivered and retracted. The female came to her feet and walked off. Young read the female’s leg band with her binoculars. “You just hit the jackpot,” she told me. The bird was part of a female-female pair. The male had another mate.

Young started scribbling notes, and we sat there rapidly rehashing the details. The sex didn’t seem forced at all. In a rape, Young said — which, for all the talk of albatross monogamy, is not uncommon in the species — a male will pin a female’s neck to the ground, or back her into a bush to tangle her up. (One study observed four different gangs of males forcing themselves on a single female, which lost an eye in the process.) But these two birds hardly seemed in a rush. Young made more notes. Then, with the male bird frozen right where he’d been left, the female slapped her rubbery feet on the ground, caught an updraft and disappeared over the ocean.

The next morning, Young still seemed to be assuring herself that her interpretation of what we’d seen was reasonable. “We didn’t see how it started, but how it ended looked . . . ” — she searched for a precise, nonanthropomorphic phrase. She couldn’t really find one, and let out a self-effacing laugh. “Mutually beneficial?” she said. “I don’t know!”

Dave Leonard, a friend of Young’s, was tagging along. Leonard — tall, lanky and tan, with a ponytail and a few days of scruff — is an ornithologist but works a desk job now for a state wildlife agency and seemed to be enjoying a morning outside. He brandished a gigantic telephoto lens in all directions and had trouble recovering after realizing he’d forgotten to pack his binoculars. Leonard knows his birds, but he was here as a bird lover, not a bird researcher, and wasn’t overly concerned with scientific detachment. When Young pointed out a male albatross whinnying at every female that passed overhead, Leonard shook his head and joked, “I feel your pain, dude.”

Eventually, Young spotted a female from one of the female-female pairs calling to a male about 15 feet away. The female was standing right where the male and his partner usually build their nest. Her head was straight up in the air, and she clapped her beak animatedly. In Young’s experience, it was rare for a bird to call so determinedly to another that’s not her partner; this would definitely count as “solicitation,” she said, if the two birds wound up copulating. “Pull up a rock,” she told me and Leonard.

We sat on the ground expectantly for a while. Eventually, the male albatross took a few steps toward the calling female. Then it stopped and looked around. It was comical, given the circumstances.

“ ‘Will anyone see me if I cheat?’ ” Young said. “I’m not sure if he’s taking her up on it, or just going, ‘Why are you in my spot?’ ” She was doing the bird’s interior monologue, narrating for one blameless, anthropomorphic moment.

The male stopped again and tucked his beak into the feathers behind his neck. Then he turned around and retreated. The taut sexual anticipation — at least as felt by us three humans — seemed to let up. “Well, his partner should be very proud of the self-control,” Young said. Then she said, “I know when to cut my losses,” gathered up her backpack and clipboard full of hard-earned data and trudged off to watch some other birds.

MORE THAN 4,000 miles across the Pacific, at a place called Taiaroa Head in southeastern New Zealand, two female Royal albatrosses (a related species) were building their nest. Later that winter, those two birds would become one of only a few known female-female pairs to successfully fledge a chick at Taiaroa Head in more than 60 years of continuous observation of the colony. (Two years before, the same two birds had engaged in a threesome, presiding over a single nest with the help of one male — just another “alternative mating strategy” albatrosses sometimes engage in, it turns out.)

The tourism board of Dunedin, a gay-friendly region of New Zealand, held a publicity-grabbing contest to name the “lesbian albatross” couple’s chick. For months, as the paired females incubated their egg, a press officer at Tourism Dunedin issued releases, and news organizations around the world, from England to India, ran with the story. The P.R. woman also tried to interest me in a story about a flightless kakapo bird in the region named Sirocco who’d recently made a memorable appearance on the BBC — “He actually started to shag the presenter, Mark Carwardine!” she wrote to me — and “has avid followers on Facebook and Twitter!”

A biologist working with the albatrosses at Taiaroa Head, Lyndon Perriman, seemed to bristle at the idea of naming any albatrosses — “They are wild birds,” he wrote to me in an e-mail message. He noted that the female-female pair made for an inconvenient tourist attraction because their nest was not visible from any of the public viewing areas. It seemed fitting: people’s ideas about the couple were riveting enough; it wasn’t necessary to see the actual birds. The chick hatched on Feb. 1. Tourism Dunedin named it Lola. The shortlist also included Rainbow, Lady Gagabatross and Ellen.

Jon Mooallem, New York Times

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Full article and photos: http://www.nytimes.com/2010/04/04/magazine/04animals-t.html

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Researchers found that male Gulf pipefish preferred to carry eggs for attractive females.

Pipefish, like seahorses and a few other related fishes, are unusual in that it’s the male that gets pregnant. The female deposits eggs in a pouch in the male’s body, where they are fertilized and protected and receive nutrients as they develop.

Like females of many species, male pipefish are choosy about their mating partners, preferring bigger females. But in some species, females are also choosy after mating — females of some insect species will mate with several males but use only one male’s sperm for fertilization, for example. So, do male pipefish exhibit this kind of behavior — what scientists call postcopulatory sexual selection — as well?

Kimberly A. Paczolt, a doctoral student at Texas A&M University, and Adam G. Jones, her adviser, have answered this question. In a paper in Nature, they show that males will provide resources to or withhold them from developing embryos based on the female’s attractiveness.

The researchers studied Gulf pipefish, which have a brood pouch that is nearly transparent, enabling the embryos to be monitored as they develop. They bred males consecutively with two different partners, to see how one brood affected the next.

They found that if the male mated with a bigger female for the first brood, more embryos survived or were bigger. But in the second brood, fewer were successful. “If the male invests a lot in the first brood, it doesn’t have a lot of resources for the second,” Ms. Paczolt said.

Conversely, if the male mated with a smaller female first, and fewer embryos were successful, then more were in the second. In both cases, the male was making a postmating choice. “The more attractive the female, the more resources he’s willing to spend,” Ms. Paczolt said.

Henry Fountain, New York Times

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Full article and photo: http://www.nytimes.com/2010/03/23/science/23obmale.html

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More than 40 years ago, Bill Neaves, then a young Ph.D. student, discovered how an all-female, asexual species of the whiptail lizard came to be. He found that the lizard was a cross between the female species of one type of lizard and the male species of another.

But what has puzzled him for years is how this all-female species maintains its high level of genetic variation, a contribution to evolutionary fitness that typically comes from sexual reproduction.

Despite reproducing without a male partner, this lizard species has a strong presence in the wild. Now, Aracely Lutes, a graduate student at the Stowers Institute for Medical Research in Kansas City, Mo., where Dr. Neaves works, has figured out the missing piece of the puzzle. The findings were reported Sunday in the journal Nature.

In a sexually reproducing lizard species, each lizard has 23 chromosomes from its mother, and 23 from its father.

During reproduction in the all-female species, Ms. Lutes found, all 46 of the mother’s chromosomes are duplicated, resulting in 92 chromosomes in each egg cell.

Those chromosomes then pair with their identical duplicates, and after two cell divisions, a mature egg with 46 chromosomes is produced. Since crossing-over during the cell divisions occurs only between pairs of identical chromosomes, the lizard that develops from the unfertilized egg is identical to its mother.

Importantly, each new lizard is also a replication of the original. Since the original was genetically diverse, pulling its chromosomes from two different species, its carbon copy descendants are, too.

It is because of this that the species has thrived over the generations. But unlike sexually reproducing species, these lizards will probably never evolve into a stronger species, Dr. Neaves said.

They “may be really well suited for the desert Southwest,” he said, “but when the next ice age comes, it may be that all of them get wiped out.”

Syndia N. Bhanoo, New York Times

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Full article and photo: http://www.nytimes.com/2010/02/23/science/23oblizards.html

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If an expectant mother knew that dangerous creatures lurked around her, and knew also that she wouldn’t be around to take care of her young, she might be stressed.

And if she had a way to warn her young before they were born, surely she would.

Human mothers cannot do this, to the best of our knowledge. But pregnant crickets, it appears, do have the ability to forewarn. This is especially useful since crickets abandon their young after birth.

Researchers from the University of South Carolina Upstate and Indiana State University placed pregnant crickets in an enclosure where they were stalked, but not eaten, by a wolf spider, whose fangs had been coated with wax to protect the crickets.

The young of the spider-exposed mothers turned out to be more predator-savvy than those with mothers who were not exposed to the wolf spider; they stayed hidden longer, and were more likely to freeze when they encountered spider feces or spider silk.

In a second experiment, the researchers placed the juvenile crickets in an arena with a starving wolf spider with fully functioning fangs. Eventually, the spider got all the crickets, but the young born from spider-exposed mothers lasted longer in the arena of death.

The research was published last month in The American Naturalist.

What remains unclear is exactly how the crickets are warning their unborn. “We don’t know a specific mechanism,” said Jonathan Storm, a professor at the University of South Carolina Upstate in Spartanburg and one of the authors of the paper.

Although it is conjecture at this point, he said, “It’s possible that there could be some sort of hormone transmitted.”

Sindya N. Bhanoo, New York Times

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Full article and photo: http://www.nytimes.com/2010/02/23/science/23obcrick.html

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Mary Anning was one of the few women to make a success in paleontology and one of the fewer still whose success was not linked to that of a paleontologist spouse (or any spouse: she was single). She made five major fossil discoveries from 1811 to her death in 1847, and many lesser ones.

Why then is she best known as the inspiration for the tongue twister “She sells sea shells by the seashore”?

The answer lies in her gender, her poverty, her lack of formal education, her regional accent — as it might even today. But as Shelley Emling says in “The Fossil Hunter,” her readable biography of Anning, she had one major advantage in the place and time of her birth: Lyme Regis, 1799.

The beach at Lyme Regis, on the southern coast of England, was littered with fossils, and every storm tore away at the limestone cliffs to reveal new treasures. The area is now a Unesco World Heritage Site known as the Jurassic Coast. But when Anning was born it was an isolated village.

Anning’s finds, beginning with her first major discovery, when she was 12, coincided with the emerging debate over extinction. In 1811, she found a complete ichthyosaur, the first extinct animal known to science. The concept of extinction struck at the very heart of the prevailing belief that God’s creatures were immutable and eternal, fueling a debate that preoccupied early 19th-century Christians that continues over intelligent design.

Scientists like William Buckland, Henry de la Beche and William Conybeare walked the beach with Anning and wrote about her discoveries, which came in quick succession and soon included the first complete plesiosaur and the first British pterosaur. Too often she received no credit. (She also often received no money, though fossil hunting was the family’s primary source of income.)

Ms. Emling cites numerous instances throughout Anning’s life of a scientist’s or an institution’s failing to acknowledge her role. As a contemporary wrote, “Men of learning have sucked her brains and made a great deal by publishing works, of which she furnished the contents, while she derived none of the advantages.”

A rigorous autodidact, Anning taught herself comparative anatomy by dissecting marine animals. She read as much scientific literature she could find, at one point asking the British Museum for a complete list of its holdings. She cleaned and prepared her specimens so professionally that when a prominent scientist brought her ichthyosaur to public attention, he praised the preparation — but credited the collector, apparently unable or unwilling to grasp that a girl could have been responsible. She documented her finds with skillful scientific drawings.

Anning was plucky, determined, fearless and undaunted by the odds. Despite her not having formal education, she nevertheless made a lasting contribution to science. It is no wonder that she has been the subject of several children’s books. Now “The Fossil Hunter” and “Remarkable Creatures,” a novel by Tracy Chevalier, the author of “Girl with a Pearl Earring,” are appearing almost simultaneously.

Ms. Chevalier focuses on Anning’s early life and her relationship with another historic figure, Elizabeth Philpot, vividly imagining the former’s inner life. But the merging of fact and fiction can be frustrating because it is hard to know which is which.

Did the eminent French naturalist Georges Cuvier, for instance, send a condescending letter to Anning suggesting her plesiosaur was fraudulent? The historic record shows that he had doubts about its authenticity, but was such a letter written? In the novel, Philpot storms a Geological Society meeting in London in a satisfying rush to Anning’s defense. But did she?

Ms. Emling’s approach is journalistic, but she seems not to trust the inherent interest of her facts and too frequently semifictionalizes her narrative by suggesting what “might have” happened. Too many might haves, probablys and possiblys distract from a story than can stand on its own.

Her amply footnoted book skillfully puts Anning’s work into the scientific and sociological context. But some readers may wish she had also taken a more contemporary perspective. Amateur excavations are sometimes considered looting, and it would be interesting to know how Anning would have fared today. Nor does Ms. Emling tell readers whether the lack of scientific context recorded during Anning’s excavations limited the value of her finds.

Anning died of untreated breast cancer in 1847, a painful death not untypical of the times. Though she once described herself as “well known throughout the whole of Europe,” true scientific recognition was late in coming. Toward the end of Anning’s life, the naturalist Louis Agassiz named two different species of fossil fish after her.

Anning’s death was noted in the annual presidential address at the Geological Society, which did not accept women as fellows until 1919. As the 200th anniversary of her first discovery nears, these two books remind us that she was more than the girl who sold sea shells by the sea shore.

Katherine Bouton, New York Times

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Full article and photo: http://www.nytimes.com/2010/02/02/science/02scibooks.html

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BUZZING The path of a bee as it learned the configuration of a human face. Researchers found that bees could also distinguish one face from another.

A honeybee brain has a million neurons, compared with the 100 billion in a human brain. But, researchers report, bees can recognize faces, and they even do it the same way we do.

Bees and humans both use a technique called configural processing, piecing together the components of a face — eyes, ears, nose and mouth — to form a recognizable pattern, a team of researchers report in the Feb. 15 issue of The Journal of Experimental Biology.

“It’s a kind of gluing,” said Martin Giurfa, a professor of neural biology at the University de Toulouse, France, and one of the study’s authors.

It is the same ability, Dr. Giurfa said, that helps humans realize that a Chinese pagoda and a Swiss chalet are both abodes, based on their components.

“We know two vertical lines, with a hutlike top,” he said. “It’s a house.”

In their research, Dr. Giurfa and his colleagues created a display of hand-drawn images, some faces and some not.

The faces had bowls of sugar water in front of them, while the nonfaces were placed behind bowls containing plain water. After a few failed trips to the bowls without sugar water, the bees kept returning to the sugar-filled bowls in front of the faces, the scientists found.

The images and the bowls were cleaned after every visit, to ensure that the bees were using visual cues to find the sugar and not leaving scent marks.

The researchers found that bees could also distinguish a face that provided sugar water from one that did not.

After several hours’ training, the bees picked the right faces about 75 percent of the time, said Adrian Dyer, another author of the study and a vision scientist at Monash University in Australia.

The researchers said that while they were biologists and not computer scientists, they hoped their work could be more widely used, including by face recognition experts. “If somebody else finds it interesting and it improves airport security, that’s great,” Dr. Dyer said. “The potential mechanisms can be made available to the wider facial recognition community.”

Dr. Giurfa said that the benefit of studying a creature as simple as the bee was in knowing that it did not take a complex neural network to distinguish objects. This could offer hope to technologists, he said.

“We could imagine that through repeat exposure, we may be able to train machines to extract a configuration and know that ‘This a motorbike’ or no, ‘This is rather a dog,’ ” he said.

But while the research on bees is interesting, it does not help with the most difficult problem technologists are having, said David Forsyth, a computer science professor at the University of Illinois, whose research focuses on computer vision.

That challenging problem is to build systems that can recognize the same people over a period of time, Dr. Forsyth said, after their hair has grown, or when they have sunglasses on, or after they have aged. These are all tasks that humans can usually perform but that computers struggle to replicate.

“I highly doubt that bees can tell the difference,” Dr. Forsyth said, adding, “If bees did that, I’d fall off my chair.”

Nonetheless, he said, it is important to add to the body of research on face recognition by studying animals.

While computers have become very capable at detecting faces, dependable face recognition by machines continues to be elusive.

“We know almost nothing about recognition, but it is really useful and really hard, and it helps us make decisions about the world,” Dr. Forsyth said. “Research into anything about identifying and recognizing seems to be a good thing.”

Sindyan N. Bhanoo, New York Times

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Full article and photo: http://www.nytimes.com/2010/02/02/science/02bees.html

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Reconstruction of two Sinosauropteryx, sporting their orange and white striped tails.

What color were dinosaurs? Well, at least one of them had a feathered mohawk tail in a subdued palette of chestnut and white stripes.

That is what a team of Chinese and British scientists reported Wednesday in Nature, providing the first clear evidence of dinosaur colors from studies of 125-million-year-old fossils of a dinosaur called Sinosauropteryx.

“We might be able to start painting a picture in color of what these things looked like,” said Lawrence M. Witmer, a paleontologist at Ohio University, who was not involved in the study.

Pigment-bearing melanosomes, inset, hint at dinosaur colors.

Of course, such pictures have been painted many times, but the colors were products of a painter’s imagination, not a scientist’s laboratory.

Dinosaur fossils are mostly drab collections of mineralized bones. A few preserve traces of skin, and fewer still preserve structures that many scientists have argued are feathers.

In the new study, Michael Benton, a paleontologist at the University of Bristol, and colleagues have analyzed the structures of what appear to be feathers and say they match the feathers of living birds down to the microscopic level. They used microscopic features to determine the ancient feathers’ color. The study builds on earlier work on fossil bird feathers by Jakob Vinther, a graduate student at Yale, and his colleagues. In 2006, Mr. Vinther discovered what looked like an ink sac preserved in a squid fossil. Putting the fossil under a microscope, he discovered the sac was filled with tiny spheres. The spheres were identical to pigment-loaded structures in squid ink, known as melanosomes.

Mr. Vinther knew that melanosomes created colors in other animals, including bird’s feathers. He and his colleagues made a microscopic inspection of fossils of feathers from extinct birds. They discovered melanosomes with the same sausage-shaped structure as those found in living birds. By analyzing the shape and arrangement of the fossil melanosomes, they were able to get clues to their original color. They determined, for example, that a 47-million-year-old feather had the dark iridescent sheen found on starlings today.

Dr. Benton was intrigued when he read Mr. Vinther’s research and immediately wondered what it might mean for dinosaurs.

Starting in the 1970s, a growing number of paleontologists argued that birds had evolved from a two-legged group of dinosaurs called theropods. The paleontologists pointed to traits in their skeletons found elsewhere only in birds. In 1996, Chinese paleontologists discovered an exquisitely preserved fossil of a miniature theropod, called Sinosauropteryx, that had whiskerlike structures on its head and back.

Some paleontologists argued that these whiskers were simple feathers. Skeptics have claimed that the structures were just shredded collagen fibers and that Sinosauropteryx had a smooth reptilian skin.

Since then, however, scientists have found a number of well-preserved theropod fossils with many more featherlike structures, corresponding to downy feathers and feathers with vanes. Scientists have even found bumps on the arm bones of dinosaurs, where the quills had attached. If all of these structures really were feathers, Dr. Benton reasoned, then they might have melanosomes. He and colleagues from the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing set out to look for them in fossils of ancient birds and dinosaurs, including Sinosauropteryx.

The search was brief. “Essentially,” Dr. Benton said, “wherever you look, you find it.”

One of the dinosaurs Dr. Benton and his colleagues looked at, known as Sinornithosaurus, was a 125-million-year old squirrel-sized dinosaur covered in complex feathers. In a small sample of its fossil, the scientists found two types of melanosomes. One sort produces hues in birds ranging from gray to black; the other makes reddish tints.

The scientists also looked at a piece of the tail of Sinosauropteryx, the first feathered dinosaur ever found. They discovered melanosomes producing a reddish color that alternated with white regions. “I think the authors make quite a compelling case,” said Dr. Witmer, of Ohio University, adding that the study decisively closes the case on whether the whiskers are feathers or collagen.

One skeptic was not as impressed. Theagarten Lingham-Soliar of the University of KwaZulu-Natal in South Africa argued that the researchers should have investigated whether dinosaurs without so-called feathers also had melanosomes in their skin. “Regrettably, I have to say the study would not pass muster in college science,” Dr. Lingham-Soliar said in an e-mail message.

Dr. Benton rejects such criticisms. “These filaments are feathers,” he said. “They’re not shredded tissue: they’re stuffed with melanosomes.”

The discovery also offers clues to the early prehistory of birds. Richard O. Prum, an evolutionary biologist at Yale and a collaborator with Mr. Vinther, has argued that Sinosauropteryx’s whiskers represent an early stage in the evolution of feathers.

“It’s an important advance to show that this dino fuzz really is feathers,” Dr. Prum said.

Dr. Prum and Mr. Vinther are doing the same kind of research, examining dinosaur fossils for melanosomes.

Mr. Vinther said that the study published Wednesday did not have enough detail to provide a full-blown picture of a dinosaur’s color patterns. “One or two samples is not going to do it,” he said.

Carl Zimmer, New York Times

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Full article and photos: http://www.nytimes.com/2010/01/28/science/28dino.html

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BRRRR! Insects have evolved various cryoprotective substances. The Alaskan Upis beetle can survive exposure to temperatures to as low as minus 100.

In the bleak midwinter

Frosty wind made moan,

Earth stood hard as iron,

Water like a stone;

Snow had fallen, snow on snow,

Snow on snow,

In the bleak midwinter

Long ago.

— Christina Rossetti (1872)

As the mercury plunges to its annual lows, those of us at higher latitudes retreat to cozy shelters. We might sympathize with the birds and the squirrels that endure the subfreezing cold outside and fill some feeders, but we don’t give any thought to smaller, less appealing creatures — the insects and spiders, for instance, that inhabited the backyard or woods in the summer.

They will re-emerge in the spring, so somehow they must make it through the bitter cold. How do these animals survive the deep freeze without the benefit of fur or feathers?

The threat to life at low temperatures is not really cold, but ice. With cells and bodies composed mostly of water, ice is potentially lethal because its formation disrupts the balance between the fluids outside and inside of cells, which leads to their shrinkage and irreversible damage to tissues.

Insects have therefore evolved all sorts of ways to avoid freezing. One strategy is to escape winter altogether. Butterflies like the monarch migrate south. A great solution, but this is a relatively rare capability. Most insects remain in their local habitat and must find some other way to avoid freezing. They evade the ice by crawling into holes or burrows below the snow cover and frost line, or, as some insect larvae do, by overwintering on the bottoms of lakes and ponds that do not completely freeze.

But many insects, and other animals, defend themselves against direct exposure to subfreezing temperatures through biochemical ingenuity, by producing antifreeze. In a previous column, I explained how different animal species defend themselves against predators with the same molecule acquired from their environment. By contrast, the story of defense against the cold is one of widespread and diverse innovations.

The first animal antifreezes were identified several decades ago in the blood plasma of Antarctic fish by Arthur DeVries, now at the University of Illinois, and his colleagues. The ocean around Antarctica is very cold, about 29 degrees Fahrenheit. It is salty enough to stay liquid several degrees below the freezing temperature of fresh water. The abundant ice particles floating in these waters are a hazard to fish because, if ingested, they can initiate ice formation in the gut and then — bang, you have frozen fish sticks. Unless something prevents the ice crystals from growing.

That is what the fish antifreeze proteins do. The tissues and bloodstream of about 120 species of fish belonging to the Notothenioidei family are full of antifreeze. These proteins have an unusual repeating structure that allows them to bind to ice crystals and to lower the minimum temperature at which the crystals can grow to about 28 degrees. That is just a bit below the minimum temperature of the Southern Ocean and about two full degrees lower than the freezing point of fish plasma that does not have antifreeze. This small margin of protection has had profound consequences. Antifreeze-bearing fish now dominate Antarctic waters.

The ability to survive and thrive in frigid water is impressive, but insects must survive much colder temperatures on land.

Some, like the snow flea, are active even in winter and can be found hopping about on snow banks when the temperature is as low as 20 degrees. These bugs are not really fleas, but springtails, a primitive wingless insect that can leap long distances using its tail. Laurie Graham and Peter Davies at Queen’s University in Kingston, Ontario, isolated antifreeze proteins from snow fleas and discovered that they also had a simple repeating structure that bound to ice and prevented crystal growth.

The snow flea antifreeze proteins have an entirely different composition from those of antifreezes that have been isolated from other insects, like the fire colored beetle, which has antifreeze proteins that are in turn different from those of the spruce budworm caterpillar. And all of these insect antifreezes are distinct from the kind that keeps Antarctic fish alive. Each animal’s antifreeze is a separate evolutionary invention.

But insect innovation goes beyond antifreeze. Biologists have discovered another strategy for coping with extreme cold: some bugs just tolerate freezing.

In the most northern climates, like the interior of Alaska, midwinter temperatures fall as low as minus 60 degrees Fahrenheit, and snow cover and subzero temperatures can last until May. At these extreme temperatures, most insects are bugsicles. The Alaskan Upis beetle, for example, freezes at around minus 19 degrees. But, remarkably, it can survive exposure to temperatures as low as about minus 100 degrees.

To tolerate freezing, it is crucial that insects minimize the damage that freezing (and thawing) would normally cause.

Insects have evolved a variety of cryoprotective substances. As winter approaches, many freeze-tolerant insects produce high concentrations of glycerol and other kinds of alcohol molecules. These substances don’t prevent freezing, but they slow ice formation and allow the fluids surrounding cells to freeze in a more controlled manner while the contents of the cells remain unfrozen.

For maximum protection, some Arctic insects use a combination of such cryoprotectants and antifreezes to control ice formation, to protect cells and to prevent refreezing as they thaw. Indeed, a new kind of antifreeze was recently discovered in the Upis beetle by a team of researchers from the University of Notre Dame and the University of Alaska-Fairbanks. Unlike the protein antifreezes of other beetles, snow fleas and moths, the Upis antifreeze is a complex sugar called xylomannan that is as effective at suppressing ice growth as the most active insect protein antifreezes.

The necessity of avoiding freezing has truly been the mother of a great number of evolutionary inventions. This new finding raises the likelihood that there are more chemical tricks to discover about how insects cope with extreme cold.

This is not merely a matter of esoteric Arctic entomology.

A long-standing challenge in human organ preservation has been precisely the problem that these insects have solved — how tissues can be frozen for a long time and then thawed out successfully. Research teams are now exploring how to apply insights from the animal world to the operating room.

Sean B. Carroll, a molecular biologist and geneticist, is the author of “Remarkable Creatures: Epic Adventures in the Search for the Origin of Species.”

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Full article and photo: http://www.nytimes.com/2010/01/19/science/19creatures.html

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But did the early ancestor of Man learn how to control it?

Observations of chimpanzees could shed light on when our human ancestors first controlled fire

Wild chimpanzees have been observed carrying out a “fire dance” in front of grassland wildfires as part of a suite of unusual behaviours that could indicate an ability of man’s closet living relative to understand and even control fire.

 Instead of fleeing the wildfires in panic, the chimps were seen to monitor them carefully, showing no signs of the fear that other animals normally exhibit. Their leader – the alpha male – was even observed performing a ritualistic display while facing the flames.

The observations could shed light on when our human ancestors first controlled fire – a key stage in human evolution. Scientists said that if chimps are able to understand the nature of fire then the same could have been true for the small-brained, ape-like ancestors of humans that lived millions of years ago.

Jill Pruetz, an anthropologist at Iowa State University in Ames, said that she observed the fire-dancing behaviour a couple of times in a group of chimps living in a savannah region at Fongoli in Senegal where wildfires often occur towards the end of the dry season.

“I saw it a couple of times in 2006 and I was really surprised at how good the chimps were at predicting the behaviour of fire. These were basically fires that occur at the end of the dry season and they can burn very hot and can move very fast,” Dr Pruetz said.

“They were much better than I was in predicting how the fire would move. In one case the fire was around us on three sides yet they were very calm and they minimised the distance and the amount of time they had to move.”

The “fire dance” of the alpha male was similar to the rain-dancing behaviour observed by primatologist Jane Goodall, when the dominant chimp would begin to sway in slow motion at the signs of an approaching storm, Dr Pruetz said.

“Chimps everywhere have what is called a rain dance and it’s just a big male display to show dominance,” she said. “Males display all the time for a number of different reasons, but when there’s a big thunderstorm approaching they do this exaggerated display, it’s almost like slow motion.

“When I was with this one party of chimps at Fongoli, the dominant male did the same sort of thing, but it was towards the fire, so I called it the fire dance.

“It wasn’t directed at other members of the group but at the fire itself. As the fire approached them, and the sound of cracking and popping was really deafening, the male started this exaggerated display.”

At one point, the leader of the group appeared to emit a barking noise unlike any other warning sound that the chimps use to communicate danger to one another. “This happened before the fire dance. I could hear it for literally hundreds of metres,” Dr Pruetz said.

“The chimps became more timid as the fire came closer, and the alpha male went out of sight and I heard him give this variation of a warning bark. I had never heard this particular vocalisation before. It seemed to me to be specific to the fire, but I don’t know what he was communicating,” she said.

Equally surprising was the general calmness of the group to an approaching fire, even when the smoke and flames were clearly visible. Dr Pruetz said that she was astonished at how calm the chimps were and this could be a key stage in the control of fire: “It’s important to conceptualise fire in order to overcome the fear of it. Some people think that for humans there is an innate fear of fire and to overcome it is the first step in ultimately controlling it and being able to make fire.

“I think that chimps are perfectly capable of controlling fire. We watch their behaviour in the face of fire and we think they can conceptualise fire, and we see that captive apes can control fire. But they we have to ask why would they do it [in the wild], what is the impetus?”

The study, to be published in the American Journal of Physical Anthropology, lends support to the idea that the control of fire occurred relatively early in human evolution. Although there is archaeological evidence from burnt remnants that human ancestors controlled fire more than a million years ago, some scientists believe this is contentious. The earliest hearths, which are indisputable evidence for the control of fire, date to less than 1 million years old.

Dr Pruetz said: “Our data contributes to the argument in that, if we have this animal that is small-brained but cognitively sophisticated, then maybe we should rethink those data from Australopithecines [early human ancestors] in how they may have reacted to fire and reconsider the data at some sites that indicate there was some kind of control of fire.”

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Full article and photo: http://www.independent.co.uk/news/science/fire-holds-no-fears-for-chimps-says-scientist-1869307.html

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