Lady XPosted: December 25, 2010
Well, actually it’s X-Woman but Lady X made a better title. The science of genetics is exciting and has turned up so much important information recently that it’s made the Theory of Evolution ironclad. This discovery of a new species of old humans is just about the most interesting read I’ve seen in a long time. I took a lot of anthropology courses at university and was terrifically fascinated by Neanderthals. This appears to be a species with some ties to them. Yes, I still read The National Geographic and have read it since my grandparents bought me a subscription in the early 60s. I was a ardent fan of Louis and Mary Leaky.
A previously unknown kind of human—the Denisovans—likely roamed Asia for thousands of years, probably interbreeding occasionally with humans like you and me, according to a new genetic study.
In fact, living Pacific islanders in Papua New Guinea may be distant descendants of these prehistoric pairings, according to new analysis of DNA from a girl’s 40,000-year-old pinkie bone, found in Siberian Russia‘s Denisova cave.
This “new twist” in human evolution adds substantial new evidence that different types of humans—so-called modern humans and Neanderthals, modern humans and Denisovans, and perhaps even Denisovans and Neanderthals—mated and bore offspring, experts say.
The article also links to an even more interesting topic area: “Interspecies Sex: Evolution’s Hidden Secret?”.
There appears to be some evidence that Denisovans, Neanderthals, and Homo Sapiens did some species mixing. This is also a new item because it was previously thought that Neanderthals and Homo Sapiens kept to themselves. Well, I guess that was true for awhile if you were a scientist and not a reader of The Clan of the Cavebear series.
The centerpiece of the DNA study is a Denisovan fossil finger bone discovered in 2008. The fossil is thought to be from a young girl—dubbed X-woman—who was between 5 and 7 years old when she died.
For a previous Nature study, released in March 2010, the team had collected and sequenced mitochondrial DNA, or mtDNA, from X-woman’s finger. But mtDNA—inherited only from mothers—contains far less information about a person’s genetic makeup than DNA found in the nucleus of a cell, or nuclear DNA (see a quick genetics overview).
In the new study the team reports successfully extracting and sequencing nuclear DNA from the bone.
Then, using DNA-comparison techniques, the scientists were able to determine that Denisovans were distinct from both modern humans and Neanderthals, yet closely related to the latter.
The team estimates Denisovans split from the parent group of Neanderthals about 350,000 years ago.
One of the interesting things will be seeing if scientists can piece together the Denisovan move from places around eastern Europe to New Guinea.
“We don’t think the Denisovans went to Papua New Guinea,” located at the northwestern edge of the Pacific region called Melanesia, explained study co-author Bence Viola, an anthropologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
“We think the Denisovan population inhabited most of eastern Eurasia in the same way that Neanderthals inhabited most of western Eurasia,” Viola said. “Our idea is that the ancestors of Melanesians met the Denisovans in Southeast Asia and interbred, and the ancestors of Melanesians then moved on to Papua New Guinea.”
The study of Melanesia is another thing that has expanded recently. The DNA findings of X-Woman was reported by WaPo in March of this year.
A team of European researchers has identified a new lineage of proto-human that left Africa about a million years ago, traveling as far as Siberia and then dying out — a discovery that raises new questions about early human history.
The existence of the new lineage was discovered by analyzing DNA extracted from a single bone fragment, according to a study published Wednesday in the journal Nature. What the beings looked like, how they lived and what happened to them are a mystery. All that’s known is that they existed as recently as 40,000 years ago, which is the approximate age of the bone.
“Whoever carried this DNA out of Africa is some new creature that hasn’t been on our radar screen so far,” said Johannes Krause, a researcher at the Max Planck Institute for Evolutionary Anthropology in Germany, who helped lead the research team.
It seems that are now closer to calling little Lady X a member of a new species. This means we seem to have a new set of cousins to add to our family tree! This is really exciting!!