....another discovery, this time in Siberia, of a previously unknown relative.
DNA samples suggest that a group of unknown hominids ventured out of Africa less than a million years ago.
“It was a shock to find DNA from a new type of ancestor that has not been on our radar screens,” says geneticist Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. These enigmatic hominids left Africa in a previously unsuspected migration around 1 million years ago, a team led by Pääbo and Max Planck graduate student Johannes Krause reports in a paper published online March 24 in Nature 2
An international team has sequenced genetic material from the fossil showing that it is distinct from that of Neanderthals and modern humans.
Details of the find, dubbed the find, "X-woman" 3
This curious sequence was extracted from a piece of finger bone unearthed in 2008 at Denisova Cave in southern Siberia’s Altai Mountains. Previous excavations of stone and bone artifacts in the cave indicated that modern humans and Neandertals lived there periodically beginning at least 125,000 years ago. Few fossils have turned up at the site.
While retrieving DNA from presumed Neandertal fossils in November 2009, Krause noticed an unusual mitochondrial sequence. Mitochondrial DNA is located outside the cell nucleus and inherited from the mother. 2
The proof of the pudding, as they say.......
The divergence date of one million years is too young for the Denisova hominin to have been a descendent of Homo erectus, which moved out of Africa into Asia some two million years ago.
And it is too old to be a descendent of Homo heidelbergensis, another ancient human thought to have originated around 650,000 years ago. However, for now, the researchers have steered away from describing the specimen as a new species.
Other experts agreed that while the Siberian specimen may be a new species, this has yet to be shown.
"We really don't know," Ian Tattersall of the American Museum of Natural History in New York, told the Associated Press news agency.
Dr Tattersall, who wasn't involved in the new research, added: "The human family tree has got a lot of branchings. It's entirely plausible there are a lot of branches out there we don't know about." 3
1. Patrick Lockerby, SciBlog article June 13th 2009