Just as humans and gorillas share a common evolutionary ancestry, the pubic lice that infuriate some members of the two species are also related. Pubic lice–known to scientists as Pthirus pubis and to most other people as “crabs”–are thought to have evolved from Pthirus gorillae, the structurally similar species that infests gorillas. Genetic analysis by David Reed at the University of Florida indicates that the lice lineages split about 3.3 million years ago, whereas it is believed that humans diverged from gorillas at least 7 million years ago. This suggests that “early humans somehow caught pubic lice from their gorilla cousins.”
But apparently the lousy parasite didn’t make the jump because humans and gorillas tried to reunite their bloodlines; no, University College London biologist Robin Weiss suspects that humans picked up crabs by hunting gorillas. Because a predator can easily pick up parasites from its prey, the lice could have jumped to early humans while they butchered gorillas for bushmeat. Some researchers say that HIV made its more recent jump from chimpanzees to humans the same way.
Image: Flickr / mrflip
Unlike a lot of humans, robots had a great week. They’ve begun to evolve, they’re helping babies with mobility disorders, and one even brought Einstein back to life… sort of.
In the past, for robots to adapt to any physical changes, they needed their control software to be redesigned. Now, engineers in the U.K. have developed a robot that has a “brain” that can develop, in both size and complexity, along with its physical body. Their hope is that the brain will advance the robot to a more humanlike being that can grow over time, like humans and other biological creatures. “After all,” said Sethuraman Muthuraman, one of the scientists, “if you want to develop a complex robot why not take the same route as biology did?”
Meanwhile, at the University of Delaware, scientists have developed a “tiny power chair” that can help babies with mobility problems explore the world at an earlier age. Children with conditions like cerebral palsy and spina bifida are not usually mobile until three years old, when they can use a traditional motor wheelchair. But with a joystick, babies as young as six months can operate the new robot-enhanced chair, which the university is currently working to bring to the market.
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Though some believe humans have reached the dead-end of our evolutionary journey, small skink lizards (Lerista) seem to still be in the thick of it. Skink lizards already have elongated, snake-like bodies with relatively small, shrunken legs. Now, new research [pdf] finds that the lizards are giving up walking for good, and have been rapidly evolving away their limbs.
Adam Skinner of the University of Adelaide performed a genetic analysis on several species of skink lizards with different sized limbs. He found that there have been at least ten independent reductions in limbs throughout the lizards’ evolution, without any signs of reversal. Some species now have fewer digits (lizard fingers) while others have lost whole limbs. Complete loss of limbs could have occurred in as little as 3.6 millions years—a blink of an eye in evolutionary terms.
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Religion has a funny way of dividing people. But religious fervor and intolerance may also keep you from getting sick, according to evolutionary biologists Corey Fincher and Randy Thornhill of the University of New Mexico. They propose a theory that says religious diversity was an evolutionary adaptation to keep groups of people separate and prevent them from infecting each other with diseases.
The researchers noted that religious diversity varies significantly across the globe. Why does Brazil have 159 religions while Canada only has 15? Fincher and Thornhill believe there is a relationship between geography, climate, and religious diversity. Since warmer locales harbor more infectious diseases, it was a good survival strategy to keep to yourself and religion enforced isolation.
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Break a mirror and you’re stuck with bad luck. Walk under a ladder and you’re tempting fate. Sound ridiculous? Scientists believe such beliefs may be genetic, part of adaptive behaviors passed on to create an evolutionary advantage to surviving impeding danger.
Boiled down, a superstition is the belief that one event caused another event, without any evidence of the link. “All animals will display behaviors that imply a causal relationship that isn’t there,” says Kevin Foster, evolutionary biologist at Harvard University. Foster uses a pigeon as an example: The pigeon will take flight if it hears a hand clap, the same way it would react if it heard a gun shot.
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· James Watson and E.O. Wilson talk Darwin with Charlie Rose.
· The perfect way to scare off would-be sandwich thieves: fake mold.
· Times are changing on the Internet: Nobody has time to look for porn anymore.
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The Charles Darwin news keeps on coming this week.
Yesterday we reported on the fracas at Britain’s Royal Society, where Nobel laureates threw a fit after the society’s education director, Michael Reiss, appeared to endorse science teachers discussing creationism. Reiss tried to say that he was misquoted, but it was too little, too late: Today he formally resigned.
If Reiss is honest that he was misrepresented, and he really meant that science teachers should be able to discuss (but not endorse) creationism with students who bring it up, then his departure is unfortunate. First, it’s more fodder for those peddling the nonsense that science is just like a religion because it persecutes dissenters. And second, Reiss is right: Teachers need to be able to talk to creationist students. Dismissing them as dumb or informed is no way to get students interested in science.
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Ostriches, kiwis, emus—these birds always look out of place, bound to the land while their feathered cousins take to the sky. It’s easy to imagine that flightlessness evolved only once, and that bird species then split into several species; indeed, most scientists figured that was what happened. But according to a study led by John Harshman of the Field Museum of Natural History in Chicago, that’s not so: Birds lost the ability to fly at least three times.
Harshman’s team began to poke holes in the common ancestor hypothesis by examining DNA from the different birds to see how they were related. The researchers found that emus and kiwis were actually more closely related to a ground-dwelling but flight-capable bird called the tinamous, which lives in the Americas, than they were to ostriches.
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Many ants are known to be slave masters—their raiding parties steal the young from colonies of rival ants and raise the foreigners as workers in their own nest. However, Susanne Foitzik of Ludwig-Maximilians University in Munich may be the first researcher to study an ant slave rebellion.
The rebels are Temnothorax, tiny ants only about the size of the comma in this sentence. Their captors are called Protomognathus americanus, and despite being only a little larger, these bullies enslave the smaller insects. Inside the larger ants’ nest, which is built inside an acorn, the smaller ants are put to work caring for their masters’ young. But sometimes, Temnothorax slaves revolt against their servile existence and slaughter the Protomognathus larvae they’re supposed to be babysitting, as well as some of the enemy workers.
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Bdelloid rotifers have maintained a celibate aquatic existence for 80 million years. They are an all-female type of small invertebrates that occasionally produce a child via asexual reproduction—a clone breaks off directly from the mother. But bdelloids have not only survived through the ages, they’ve managed to evolve and diversify without the genetic intermingling that comes along with sex. Now Harvard University biologists think they have figured out the bdelloid’s trick.
In a study published today in Science, the research team, led by Eugene Gladyshev, wrote that bdelloids can take DNA not only from other members of their own species, but also from bacteria, fungi, and even plants. When its freshwater habitat temporarily dries up, a bdelloid’s cellular membranes break and its genome tears apart. But disintegrating DNA isn’t enough to kill this hardy creature—when water returns, a bdelloid can pick up its own pieces and put itself back together.
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