|03-25-2010, 12:50 AM||#1 (permalink)|
Join Date: Apr 2007
40,000 Year Old Human Bone Discovered
40,000-Year-Old Bone Could Be New Species of Human - AOL News
Ancient Bone Could Be New Species of Human
(March 24) -- Ancient humans, Neanderthals and the now-famous hobbits may have had another human-like neighbor about 40,000 years ago. Thanks to a bone fragment discovered in Siberia's Altai Mountains, scientists may be on the cusp of adding a new species to our hominin family.
The researchers, led by Johannes Krause and Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology, are hesitant to make that claim just yet, but their follow-up work could remove the uncertainty. Krause tells AOL News that the real importance of the finding, and the research to come, is what it says about what makes modern humans unique. "This new form of hominin can help us to identify what has changed in our genome in the last few hundred thousand years -- what defines us as a species," he says. "That is the big question."
Krause and his group, who describe their findings in the current issue of Nature, used new sequencing technology and methodologies to analyze the DNA in the bone fragment -- believed to be a chip off the pinky of a 5- to 7-year-old child -- which was uncovered in material dated to 30,000 to 48,000 years ago. Once they had sequenced the DNA, they compared it to that of modern humans and Neanderthals, both of which were living in the Altai Mountains in that time period, and found a surprising number of differences. "It really looked like something that I'd never seen before," Krause says. "It was a sequence which was similar in some way to humans but is still quite distinctive."
Based on these comparisons, the researchers estimate that modern humans, Neanderthals and this unknown hominin shared an ancestor about 1 million years ago. Furthermore, the predecessors of this mysterious Siberian probably migrated out of Africa not long thereafter -- an exodus that scientists hadn't suspected prior to this finding.
As for the big question of whether this child represents a new species, the scientists say they will need to study a different sort of DNA to address that for certain. In their current paper, they describe the DNA found in a part of the cell known as the mitochondria, but nuclear DNA, which they are analyzing now, will unveil the real secrets. They may even be able to determine whether this hominin line interbred with humans or Neanderthals during some of those long, cold Siberian nights.
Krause says that the next results could also paint a more complete picture of the child's physical characteristics. Much like the recent work with the 4,000-year-old Inuk, the scientists can study the DNA to estimate potential traits such as hair color or skin color.
But Krause sees such superficial characteristics as secondary to the far more important questions that lay ahead. "One million years ago, we shared an ancestor with this new form of hominin. After that we went two different ways," he explains. "We collected new mutations. Genes changed. Proteins changed. And that is what differentiates us now."
Clearly we've fared quite a bit better over time than this hominin's descendants -- as well as those of the Neanderthals -- and Krause believes his ongoing work could pinpoint the reason. "Somehow in the span of just 40,000 years we managed to colonize the whole world, so something about us is special, genetically. We are hunting after what makes humans human."
"Get baked and watch a space documentary. It'll change your life."
|10-21-2010, 05:31 PM||#2 (permalink)|
Join Date: May 2008
Location: Phoenix, AZ
I think our species history is a lot more interesting than we know. Fossils are a very rare thing, and without time travel I don't think we'll ever know the full story.
Lyle the Gamer, Fan of all things video game related.
Freethinkers are those who are willing to use their minds without prejudice and without fearing to understand things that clash with their own customs, privileges, or beliefs. This state of mind is not common, but it is essential for right thinking; where it is absent, discussion is apt to become worse than useless.
-- Leo Tolstoy