http://www.digitaljournal.com/article/289536

Siberian cave produces finger bone of 'X-woman'

Posted Mar 25, 2010 by Lynn Herrmann
Russian archaeologists have uncovered a small bone fragment from the finger of what may be a previously unknown human species, found in a cave of Siberia’s Altai Mountains.
Part of a DNA strand
DNA strand.
File
The extinct hominin, a human-like creature, is believed to have lived in Central Asia between 48,000 and 30,000 years ago. Details of the discovery, called ‘X-woman’, have been published online in the journal Nature.
BBC reports the find was discovered in 2008 from the Denisova cave in southern Siberia. Researchers have extracted mitochondrial DNA from the bone and reported today that the genetic code is distinctly different from both modern humans and Neanderthals.
The bone fragment is from the fifth finger of a child, most likely between 5 to 7 years of age. It is not known whether the child was a boy or girl. Ornaments and a bracelet were also found in the same layer as the bone fragment.
Labeling the discovery “a very exciting development,” human origins researcher Professor Chris Stringer of London’s Natural History Museum added “This new DNA work provides an entirely new way of looking at the still poorly-understood evolution of humans in central and eastern Asia.”
Analysis of the DNA was led by researchers Johannes Krause and Svante Paabo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Preliminary evidence suggests the Denisova child may be a new human species, last sharing common ancestors with Neanderthals and modern humans around one million years ago, according to The New York Times.
"Whoever carried this mitochondrial genome out of Africa about a million years ago is some new creature that has not been on our radar screens so far," said co-author Professor Svante Paabo.
This new human lineage migrated out of Africa at a different time than Homo erectus or the Neanderthals, the two known archaic human species. Homo erectus emigrated two million years ago while Neanderthal ancestors left Africa approximately 500,000 years ago.
“Back at the time this lineage came out of Africa, it had to have been a distinct group, perhaps a distinct species,” Paabo said. “But whether or not this individual was a distinct species, we have to wait for the nuclear DNA.”
Both Neanderthals and modern humans inhabited the region 30,000 years ago. Pollen analysis indicates the valley area below the cave would have been a grassy steppe, roamed by ice-age species such as the wooly rhino and wooly mammoth.
Counting the new discovery, three distinct human species may have lived within close proximity. “So the picture of humans around in the late Pleistocene gets a lot more complex and a lot more interesting,” Dr. Paabo said.