A previously unknown kind of human group vanished so completely that it has left behind the merest wisp of evidence that it ever existed — a single bone from the little finger of a child, buried in a cave in the Altai mountains of southern Siberia.
Researchers extracted DNA from the bone and reported Wednesday that it differed conspicuously from that of modern humans and of Neanderthals, the archaic human species that inhabited Europe until the arrival of modern humans on the continent about 44,000 years ago.
The child was probably 5 to 7 years old, but it is not yet known if it was a boy or a girl. The finger bone was excavated by Russian archaeologists in 2008 from a place known as the Denisova cave.
The researchers were led by Johannes Krause and Svante Paabo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. They are careful not to call the Denisova child a new human species, though it may prove to be so, because the evidence is preliminary.
But they say the genetic material, an element called mitochondrial DNA, extracted from the bone belonged to a distinct human lineage that migrated out of Africa at a different time from the two known archaic human species. Homo erectus, found in East Asia, left Africa 2 million years ago, and the ancestor of Neanderthals emigrated about 500,000 years ago. The number of differences found in the child's DNA indicate that its ancestors left Africa about 1 million years ago, the researchers say. Their report is published online in the journal Nature.
Now, science learned some time ago that Neanderthals were not a precursor to modern humans, but a separate species that lived concurrent with homo sapiens, even competing in Europe. This isn't any definite proof that another hominid species tried to claw it's way up the evolutionary ladder yet, but if it is, then the past gets more interesting, and would mean that early hominids began to leave Africa long before we previously thought. This implies a lot about our ancestors and could give indications for behavior we've not credited to our ancestors. Early man becomes an explorer much sooner, and becomes much more interesting.
Keep in mind, this is data discovered just two years ago and to extrapolate knowledge without data is just foolish, so don't think I'm assuming blindly that this is a definite new species and despite many headlines around this story, the scientists that are studying this specimen are even more cautious in calling it a new species until they have more proof. The lessons of Piltdown Man still hang in the air.