Your brain is hungry. That big gray calculating machine in your head is an energy hog that needs lots of calories—more than the diet of fruits and plants that our distant hominin ancestors probably ate could provide. It’s a mystery, then, just how human ancestors like Homo erectus—who were around when our craniums started to expand in a hurry—ate enough to start growing big brains. But buried in Kenya, a two-million-year-old hint has emerged: Those hominins started eating seafood way back then, archaeologists say.

Near a place called Lake Turkana, archaeologists David Braun found two intriguing groups of items: The bones of fish, turtles, and even crocodiles with the scars of stone tools still showing, and stone fragments that Braun says come from the simple tools these hominins used to carve up the marine animals. He and his colleagues report the find of our ancestors’ ancient feast in the Proceedings of the National Academy of Sciences.

Today, their leftovers—in the form of hundreds of bones and several thousand stone tools—are the earliest “definitive evidence” of hominins butchering and eating aquatic animals, which are rich in fatty acids essential for growing bigger brains [ScienceNOW].

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Nearly 150 years after scientists discovered the first specimen of the dino-bird archaeopteryx, we get to see what it was made of. Researchers who scanned one of the fossils with x-rays say the specimen contains not just impressions of fossils, but actually the remains of soft tissue with some of the chemical components intact. They published their findings (in press) today in the Proceedings of the National Academy of Sciences.

The team led by Roy Wogelius scanned a 150-million-year-old Archaeopteryx fossil using a synchrotron-type particle accelerator located at the Stanford Synchrotron Radiation Lightsource in California.

The synchrotron excites atoms in target materials to emit X rays at characteristic wavelengths. The scan reveals the distribution of elements throughout the fossil. The green glow of the bones in this false-colour image shows that Archaeopteryx, like modern birds, concentrated zinc in its bones. The red of the rocks comes from calcium in the limestone that had encased the fossil since the animal died [New Scientist].

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Ever since anthropologists figured out that early humans and Neanderthals coexisted for a span of prehistory, they’ve wondered–did the two species, you know, make friends? Now a fascinating new genetics study reveals that Homo sapiens and Neanderthals did indeed interbreed, and the evidence is still to be found in the human genome.

Researchers from Germany’s Max Planck Institute for Evolutionary Anthropology first sequenced the entire Neanderthal genome from powdered bone fragments found in Europe and dating from 40,000 years ago–a marvelous accomplishment in itself. Then, they compared the Neanderthal genome to that of five modern humans, including Africans, Europeans, and Asians. The researchers found that between 1 percent and 4 percent of the DNA in modern Europeans and Asians was inherited from Neanderthals, which suggests that the interbreeding took place after the first groups of humans left Africa.

Anthropologists have long speculated that early humans may have mated with Neanderthals, but the latest study provides the strongest evidence so far, suggesting that such encounters took place around 60,000 years ago in the Fertile Crescent region of the Middle East [The Guardian].

The study, published in Science and made available to the public for free, opens up new areas for research. Geneticists will now probe the function of the Neanderthal genes that humans have hung on to, and can also look for human genes that may have given us a competitive edge over Neanderthals.

Erik Trinkaus, an anthropologist at Washington University in St. Louis, who has long argued that Neanderthals contributed to the human genome, welcomed the study, commenting that now researchers “can get on to other things than who was having sex with who in the Pleistocene” [AP].

For a much deeper dive into these issues, head to Carl Zimmer’s post at The Loom and Razib Khan’s post at Gene Expression.

Related Content:
The Loom: Skull Caps and Genomes
Gene Expression: Breaking: There’s a Little Bit of Neandertal in All of Us
80beats: We May Soon Be Able to Clone Neanderthals. But Should We?
80beats: Crafty & Clever Neanderthals Made Jewelry 50,000 Years Ago
80beats: Did Spear-Throwing Humans Kill Neanderthals?
80beats: Rough Draft of the Neanderthal Genome is Complete!
DISCOVER: Works in Progress asks whether we rubbed out Neanderthals, or rubbed off on them

Image: Max Planck Institute EVA. The researchers hang out with their Neanderthal relation.

Is the Roundup Ready revolution coming to a close? In the early 1990s, agribusiness giant Monsanto introduced its line of genetically modified crops that could tolerate the pesticide Roundup, allowing farmers to spray it far and wide without worrying about damaging their product.

Now, reports are bubbling up about the increased resistance some weeds are showing to Roundup, which could be the source of great worry, as 90 percent of the soybeans and 70 percent of corn currently grown in the United States are the Roundup Ready varieties.

[F]armers sprayed so much Roundup that weeds quickly evolved to survive it. “What we’re talking about here is Darwinian evolution in fast-forward,” Mike Owen, a weed scientist at Iowa State University, said [The New York Times].

And for the environmentally-minded, here’s something else to consider:

That threatens to reverse one of the agricultural advances bolstered by the Roundup revolution: minimum-till farming. By combining Roundup and Roundup Ready crops, farmers did not have to plow under the weeds to control them. That reduced erosion, the runoff of chemicals into waterways and the use of fuel for tractors [The New York Times].

For an in-depth take, and a historical reminder of how weeds have always evolved to thwart our means of killing them, check out DISCOVER blogger Carl Zimmer’s post.

Related Content:
The Loom: How To Make a Superweed
80beats: Biotech Potato Wins European Approval; May Signal a Larger Shift on GM Crops
80beats: India Says No to Genetically Modified Eggplants
80beats: GM Corn and Organ Failure: Lots of Sensationalism, Few Facts
80beats: Bee Killer Still at Large; New Evidence Makes Pesticides a Prime Suspect
DISCOVER: “Frankenfoods” That Could Feed the World

Image: flickr / Peter Blanchard

Charles Darwin may have been right in worrying that the ill health that plagued his family were a result of inbreeding. Darwin didn’t only marry his first cousin, Emma Wedgwood–in fact, the Darwins and the Wedgwoods made a habit of intermarrying (Darwin’s maternal grandparents were also third cousins). Now a new study, which crunched the numbers on first-cousin marriages over four generations of the two dynasties, suggests that his children had an elevated risk of health problems.

The degree of inbreeding among Darwin’s children, while not excessive, was enough to increase the risk of recessive diseases — ones that occur if a harmful version of a gene is inherited from both parents. Three of his 10 children died before age 10 — 2 of bacterial diseases. Childhood mortality from bacterial infections is associated with inbreeding. So, too, is infertility, and three of Darwin’s children who had long marriages left no children [The New York Times].

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Former Roman Catholic priest and respected evolutionary biologist Francisco Ayala has won this year’s Templeton Prize. The $1.53 million award honors a living person “who has made an exceptional contribution to affirming life’s spiritual dimension, whether through insight, discovery, or practical works.” The John Templeton Foundation cited Ayala’s dogged work through the years advocating the peaceful co-existence of science and religion in its decision. The somewhat controversial prize is often given to scientists who find common ground between religion and science, but previous winners have also included more traditional spiritual leaders like Mother Teresa and televangelist Billy Graham.

Ayala is the former president of the American Association for the Advancement of Science and is respected for his research into the evolutionary history of the parasite scientists have associated with malaria, with an eye toward developing a cure for the disease. He also pioneered the use of an organism’s genetic material as molecular clocks that help track and time its origins [The Christian Science Monitor]. But he is known best, perhaps, for being an expert witness in the 1981 federal court trial that led to the overturning of an Arkansas law mandating the teaching creationism with evolution in science class. In 2001, he was awarded the National Medal of Science.

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Life: Ain’t it grand?

That seems to have been the starting point for the new nature documentary series LIFE, which spotlights some of the planet’s most gloriously unusual critters. The series, which airs on Sunday evenings on the Discovery Channel, presents animals that belong in the evolution hall of fame. Many have developed remarkable tricks to survive in inhospitable environments, while others have developed fascinating mating rituals that ensure that the fittest individuals pass on their genes, generation after generation.

Click through the gallery for some of our favorite hall-of-famers from the show.

A Restless Trail-Runner

Size does matter, especially for the tiny rufous sengi, an “elephant shrew” whose small size and constant movement makes it hungry—all the time! But movement in a forest full of predators is dangerous, so the sengi devised a clever method to forage for food.

The tiny mammal constructs a series of neatly cleared trails between its regular feeding spots and memorizes their details. Then it launches itself on a trail patrol at breakneck speed, stopping only to check for tasty insects and to clear the trail of any debris. A single twig can be fatal, so the sengi spends up to 40 percent of its time running the trails and clearing away obstacles.

In 2008, archeologists working at the Denisova Cave in Siberia’s Altai Mountains discovered a tiny piece of a finger bone, believed to be a pinky, buried with ornaments in the cave. Scientists extracted the mitochondrial DNA (genetic material from the mother’s side) from the ancient bone and checked to see if its genetic code matched with the other two known forms of early hominids–Neanderthals and the ancestors of modern humans. What they found was a real surprise. The team, led by geneticist Svaante Paabo of the Max Planck Institute, discovered that the mtDNA from the finger bone matched neither–suggesting there might have been an entirely different hominid species that roamed the planet about 50,000 years ago.

Looking back at the region and the cave, where scientists earlier discovered artifacts from humans and Neanderthals, Paabo thinks that it is possible that all the three species (modern humans, Neanderthals and the mystery hominids) could have possibly met and interacted with each other. The findings, which were published in journal Nature, present an unexpected twist in the story of human evolution and migration.

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As if living in Hawaii weren’t a great enough life, scientists have found a kind of caterpillar there that lives the best of both worlds—in water and on land. In the Proceedings of the National Academy of Sciences, Daniel Rubinoff’s team found that 12 species in the Hawaiian moth genus Hyposmocoma are amphibious in their caterpillar stage, the first amphibious insects ever found.

While most caterpillars are terrestrial (living on land), there are a few—0.5 percent—that are aquatic. However, all of the caterpillars seen before preferred either one or the other. Even classical amphibians, like the toad, often live mainly in one environment and seldom return to the other, perhaps just to lay eggs. But the Hyposmocoma caterpillars seem to have adopted a chilled-out Hawaiian way of life, comfortable with whatever environment they might be in. “They can stay underwater for an indeterminate period of time, or out of the water,” said Rubinoff, an entomologist. “There’s no other animal that I’m aware of that can do that” [Honolulu Advertiser].

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At some point in evolutionary history dogs diverged from wolves thanks to domestication by humans. But just where did dogs first become man’s best friend? Robert Wayne and his team have many years invested in answering the question, and their newest findings, published this week in Nature, suggest that the answer is the Middle East.

Researchers looked at gene segments from 912 dogs, from 85 breeds, and samples of 225 grey wolves, dog’s close cousins who they evolved from in prehistory, from 11 regions [USA Today]. Dogs and wolves that come from the Middle East, Wayne says, show the most genetic similarity. The researchers propose that dogs were first domesticated there, and then spread outward.

Dogs and wolves are closely related enough that they have interbred at various times, complicating the problem of unraveling dogs’ origin. Wayne’s team suggests that after the domestication of dogs in the Middle East, they interbred with wolves when they reached East Asia, which is how dogs and wolves there came to share some of their genetics.

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An international team of researchers has discovered how to extract DNA from fossilized bird eggs–including the eggshell of the enormous elephant bird that went extinct four centuries ago.

In a research breakthrough, scientists were able to isolate DNA from the eggshells of not just the extinct giant moa bird from New Zealand, but also a 19,000-year-old emu from Australia and the extinct elephant bird of Madagascar. The elephant bird’s egg is the largest known bird egg, with 160 times the volume of a chicken’s egg [New Scientist].

The discovery of these birds’ DNA could help scientists understand how they lived, and why they became extinct. The DNA was extracted from desiccated inner membranes in fossil eggshells, found in 13 locations in Australia, Madagascar and New Zealand [PhysOrg], and the work was published in the Proceedings of the Royal Society B.

For years scientists have been trying to extract DNA from old eggshells without success, because their approach, scientists admit, was faulty. Charlotte Oskam and Michael Bunce of Murdoch University in Perth, Western Australia, who isolated the DNA, say researchers (including themselves) were using techniques designed to extract DNA from bone, not eggshells. They even threw out the most DNA-hardy bits of eggshell [New Scientist]. Bunce explains that extracting DNA from bone involves sucking out the bone’s calcium and discarding it.

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Hot, cold, in between, it doesn’t really matter to chameleons: They’re going to snare their prey anyway, according to findings in this week’s Proceedings of the National Academy of Sciences. That’s because their elastic tongues are designed like ballistic weapons.

Chameleons fire their tongues at breakneck speed, says study leader Christopher Anderson. “A chameleon’s tongue travels at accelerations exceeding 400 meters (1,312 feet) per second squared, or about 41 Gs of force,” he added. To put that into perspective, a space shuttle only develops about three Gs of force when it takes off [Discovery News]. Given that muscle performance diminishes when it gets colder, and that these lizards are ectothermic (cold-blooded), one might think their tongue prowess would trial off sharply as temperatures drop.

Not so, Anderson says. He and his team filmed veiled chameleons (Chamaeleo calyptratus) eating crickets, and controlled the temperature as they watched. For other cold-blooded creatures, the researchers say, an 18-degree Fahrenheit drop in the temperature causes a 33 percent decrease in muscle speed, and an even more dramatic drop-off in the speed of tongue movements. But the chameleons had tongue snaps that only slowed by about 10 to 19 percent … with the same temperature decrease [Scientific American]. The chameleons’ tongues also extended to their full glory despite the temperature change.

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Will we ever get a solid answer on what killed the dinosaurs? According to a new “K-T Boundary Dream Team” comprising of 41 international experts, including geophysicists and paleontologists, yes, the question has been settled: An asteroid is indeed to blame.

For years, scientists have argued over different theories of what killed the dinos–including one hypothesis that has gained ground recently, which suggests that massive volcanic activity in India’s Deccan Traps wiped them out 65 million years ago. However, the latest expert panel stuck to the asteroid theory, saying a massive impact wiped out the dinos and more than half of the Earth’s other species. The panel’s review was published in the journal Science.

After studying all the available data on the Cretaceous-Tertiary (K-T) mass extinction, the panel concluded that the catastrophic event was caused by a 6-mile-wide asteroid that struck Earth at an angle of 90 degrees and a speed of about 12.4 miles per second – about 20 times faster than a speeding bullet [Guardian]. The asteroid hit Chicxulub, Mexico, with a force one billion times more powerful than the atomic bomb at Hiroshima [Science Daily News].

The impact of the crash would have triggered large scale fires, landslides, earthquakes that measured 10 on the Richter scale, and subsequent tsunamis, scientists said. Debris loosened by the impact would have shrouded the planet, clouding the skies, causing a global darkness, and “killing off many species that couldn’t adapt to this hellish environment” [Science Daily News], according to study coauthor Joanna Morgan.

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In this week’s Nature, researchers say they’ve analyzed a near-complete skeleton of one of the closest relatives to early dinosaurs, a silesaur called Asilisaurus. The fossil is more than 240 million years old, which is ten million years older than the earliest known fossils of true dinosaurs. The finding of this dino relative therefore suggests that dinosaurs emerged earlier than we previously believed, and it throws another surprise into the debate over their origins.

From the remains of 14 different individuals, the scientists managed to piece together what a whole skeleton looked like. However, the finished product didn’t look quite like they expected. After studying the bones for 3 years, the team concludes that Asilisaurus was about the size of a Labrador retriever. The animal walked on four legs, and the shape of its teeth suggests that it ate plants and maybe a little meat.[ScienceNOW]. That conflicted with the expectation of study coauthor Randy Irmis, who said the team would’ve thought small carnivores, and not mostly plant eaters walking on four legs, were the closest relatives to the dinosaurs.

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Male animals often use their horns to fight over females, but at least one species’ females use their horns to fight over excrement.

The species, no surprise, is the dung beetle. Unlike many of the animals we usually associate with elaborate horns, antlers, or other head weaponry—in which the male has the most impressive set—dung beetle females have horns that put the male version to shame. The reason, says a new study in the Proceedings of the Royal Society B, is that females must battle one another for that precious manure. Nicola Watson and Leigh Simmons of the University of Western Australia, Perth, pitted female dung beetles (Onthophagus sagittarius) against each other in a race for dung – a valuable resource that provides nutrients for their eggs. Matched for body size, females with bigger horns managed to collect more dung and so provide better for their offspring [New Scientist].

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