Martes, Mayo 29, 2012

Dinosaur with tiny arms unearthed in Argentina

Argentine experts have discovered the near-complete remains of a new species of Jurassic-era dinosaur that stood on its rear legs and had tiny arms, according to a leading paleontologist.
The find belongs to the Abelisaurus family, "the most common carnivorous species in the southern hemisphere during the Cretaceous Period," some 70 to 100 million years ago, paleontologist Diego Pol told AFP on Thursday.
"However the fossils that we found are some 170 million years old," from the earlier Jurassic Period, Pol said.
The creature looks a bit like a scaled-down Tyrannosaurus rex, but with even smaller arms.
The new species, baptized Eoabelisaurus mefi, predates the oldest known member of the Abelisauri lineage by more than 40 million years.
Unlike its descendants, this six-meter (20-foot) long creature creature "has completely reduced arms and tiny claws, which implies that it used only its very sharp teeth to feed itself," Pol said.
Abelisauri remains have been found only in the southern hemisphere.
Experts believe a great desert in the Earth's single land mass at the time, Pangea, could have acted as a geographic barrier, preventing the species from spreading north.
The fossils were discovered on Condor Hill, in the southern Patagonian province of Chubut, some 1,800 kilometers (1,120 miles) southwest of Buenos Aires.
A 25-member team from the Edigio Feruglio Museum of Paleontology in Chubut discovered the creature's cranium and vertebrae during a dig in 2009.
The team was forced to abandon the expedition when winter approached, and returned the next year during the summer, when "we found the animal's whole articulated skeleton," Pol said.
Details of the find appear in an article Wednesday in the Proceedings of the Royal Society of London.
Argentina earned fame as a prime site for dinosaur fossil hunters with several discoveries in the 1980s, including the Argentinosaurus Huinculensis, a giant herbivore more than 40 meters (131 feet) long that lived 98 million years ago.
In 1993, scientists in Argentina found the remains of the Giganotosaurus Carolinii, a T-Rex type creature that is the largest carnivorous dinosaur ever found.

Scientist: Evolution debate will soon be history

NEW YORK (AP) — Richard Leakey predicts skepticism over evolution will soon be history.
Not that the avowed atheist has any doubts himself.
Sometime in the next 15 to 30 years, the Kenyan-born paleoanthropologist expects scientific discoveries will have accelerated to the point that "even the skeptics can accept it."
"If you get to the stage where you can persuade people on the evidence, that it's solid, that we are all African, that color is superficial, that stages of development of culture are all interactive," Leakey says, "then I think we have a chance of a world that will respond better to global challenges."
Leakey, a professor at Stony Brook University on Long Island, recently spent several weeks in New York promoting the Turkana Basin Institute in Kenya. The institute, where Leakey spends most of his time, welcomes researchers and scientists from around the world dedicated to unearthing the origins of mankind in an area rich with fossils.
His friend, Paul Simon, performed at a May 2 fundraiser for the institute in Manhattan that collected more than $2 million. A National Geographic documentary on his work at Turkana aired this month on public television.
Now 67, Leakey is the son of the late Louis and Mary Leakey and conducts research with his wife, Meave, and daughter, Louise. The family claims to have unearthed "much of the existing fossil evidence for human evolution."
On the eve of his return to Africa earlier this week, Leakey spoke to The Associated Press in New York City about the past and the future.
"If you look back, the thing that strikes you, if you've got any sensitivity, is that extinction is the most common phenomena," Leakey says. "Extinction is always driven by environmental change. Environmental change is always driven by climate change. Man accelerated, if not created, planet change phenomena; I think we have to recognize that the future is by no means a very rosy one."
Any hope for mankind's future, he insists, rests on accepting existing scientific evidence of its past.
"If we're spreading out across the world from centers like Europe and America that evolution is nonsense and science is nonsense, how do you combat new pathogens, how do you combat new strains of disease that are evolving in the environment?" he asked.
"If you don't like the word evolution, I don't care what you call it, but life has changed. You can lay out all the fossils that have been collected and establish lineages that even a fool could work up. So the question is why, how does this happen? It's not covered by Genesis. There's no explanation for this change going back 500 million years in any book I've read from the lips of any God."
Leakey insists he has no animosity toward religion.
"If you tell me, well, people really need a faith ... I understand that," he said.
"I see no reason why you shouldn't go through your life thinking if you're a good citizen, you'll get a better future in the afterlife ...."
Leakey began his work searching for fossils in the mid-1960s. His team unearthed a nearly complete 1.6-million-year-old skeleton in 1984 that became known as "Turkana Boy," the first known early human with long legs, short arms and a tall stature.
In the late 1980s, Leakey began a career in government service in Kenya, heading the Kenya Wildlife Service. He led the quest to protect elephants from poachers who were killing the animals at an alarming rate in order to harvest their valuable ivory tusks. He gathered 12 tons of confiscated ivory in Nairobi National Park and set it afire in a 1989 demonstration that attracted worldwide headlines.
In 1993, Leakey crashed a small propeller-driven plane; his lower legs were later amputated and he now gets around on artificial limbs. There were suspicions the plane had been sabotaged by his political enemies, but it was never proven.
About a decade ago, he visited Stony Brook University on eastern Long Island, a part of the State University of New York, as a guest lecturer. Then-President Shirley Strum Kenny began lobbying Leakey to join the faculty. It was a process that took about two years; he relented after returning to the campus to accept an honorary degree.
Kenny convinced him that he could remain in Kenya most of the time, where Stony Brook anthropology students could visit and learn about his work. And the college founded in 1957 would benefit from the gravitas of such a noted professor on its faculty.
"It was much easier to work with a new university that didn't have a 200-year-old image where it was so set in its ways like some of the Ivy League schools that you couldn't really change what they did and what they thought," he said.
Earlier this month, Paul Simon performed at a benefit dinner for the Turkana Basin Institute. IMAX CEO Rich Gelfond and his wife, Peggy Bonapace Gelfond, and billionaire hedge fund investor Jim Simons and his wife, Marilyn, were among those attending the exclusive show in Manhattan's Chelsea neighborhood.
Simon agreed to allow his music to be performed on the National Geographic documentary airing on PBS and donated an autographed guitar at the fundraiser that sold for nearly $20,000.
Leakey, who clearly cherishes investigating the past, is less optimistic about the future.
"We may be on the cusp of some very real disasters that have nothing to do with whether the elephant survives, or a cheetah survives, but if we survive."

Ancient 'Sexual Revolution' Laid Foundation for Modern Family

When women started to choose good providers over manly alpha males, they created the idea of the "couple," new research indicates.
The "modern family" is characterized by monogamy and long-term partnership, a phenomenon that replaced relative promiscuity with plenty of competition between males over mates.
When this change happened is up for debate, but ancient human Ardipithecus, at 4.4 million years old, already shows that competition between males had already declined. The development of the family seems to have happened soon after the hominins and chimpanzees split from each other evolutionarily.
Over time, the study suggests, female mate choices changed; couples replaced promiscuity, while low-ranking men, who maybe weren't as strong or manly as alpha males, found a way around the male-on-male competition, by offering their services as long-term companions, rather than just sperm donors. This "sexual revolution," as the researchers called it, laid the foundation for the modern family.
Model families
In the new study, Sergey Gavrilets, a researcher at the University of Tennessee, analyzed mathematically how various theories about the development of the modern family would have played out. They show, with that analysis, that none of the previously proposed theories hold up biologically.
Using their modeling data, the researchers suggested that the only biologically feasible way for today's family to evolve would be if females started picking low-ranked males for their ability to take care of the female in a longer-term couplelike relationship (a capability called provisioning).

These males spent their time and energy providing for their mates, instead of wasting this energy competing with other males. This gave these low-ranking males a way around traditional alpha-male competition, and if it helped the females raise more, or healthier, children, the trait would be selected for, and females would start to show a preference for these provider-males.
"Once females begin to show preference for being provisioned, the low-ranked males' investment in female provisioning over male-to-male competition pays off," Gavrilets said in a statement. "Once the process was underway, it led to a kind of self-domestication, resulting in a group-living species of provisioning males and faithful females."
Effect of family
When the modern family evolved, Gavrilets says, it gave rise to parenting partnerships and the division of labor, which is important because human children take so long to grow up. While these hominin males may be working their butts off for their ladies, the ladies may still stray, Gavrilets wrote in research detailed Monday, May 28, in the journal Proceedings of the National Academy of Sciences.
"Females are not predicted to become completely faithful, but rather, the level of their faithfulness is expected to be controlled by a balance between selection for better genes (potentially supplied by top-ranked males) and better access for food and care (provided largely by low-ranked males)."