but a lot closer to home. This story's a couple of weeks old, but one of the nice things about science is that discoveries don't lose their interest or value after fifteen minutes. ("Benghazi!!1!") And whatever your personal reaction, you have to admit it's fascinating:
I admit I don't know much about the Denisovans -- here's the Wikipedia entry, which seems to be solid, except of course, that, in light of this new discovery, anything it says about the geographic distribution is open to question.
Remember when the evolutionary tree read a lot more like Genesis? "And Homo erectus begat Homo neanderthalensis, and neanderthalensis begat. . . ." Well, as is usually the case with something that simplistic, it wasn't quite that clear-cut. (Which is probably why fundamentalists of any religion have so much trouble dealing with the real world.) Twenty years ago, the idea of interbreeding between subspecies wasn't usually on anyone's radar (at least, not paleoanthropologists), even though we know it happens -- one of my favorite orchids, Cattleya guatamalensis, is a natural hybrid between C. aurantiaca and C. skinneri. There's no reason people couldn't have done the same thing -- and probably would still be doing it, except we don't seem to have any subspecies left.
In a paper in the journal Nature, scientists reported that they had retrieved ancient human DNA from a fossil dating back about 400,000 years, shattering the previous record of 100,000 years.
The fossil, a thigh bone found in Spain, had previously seemed to many experts to belong to a forerunner of Neanderthals. But its DNA tells a very different story.
It most closely resembles DNA from an enigmatic lineage of humans known as Denisovans. Until now, Denisovans were known only from DNA retrieved from 80,000-year-old remains in Siberia, 4,000 miles east of where the new DNA was found.
The mismatch between the anatomical and genetic evidence surprised the scientists, who are now rethinking human evolution over the past few hundred thousand years.
I admit I don't know much about the Denisovans -- here's the Wikipedia entry, which seems to be solid, except of course, that, in light of this new discovery, anything it says about the geographic distribution is open to question.
Remember when the evolutionary tree read a lot more like Genesis? "And Homo erectus begat Homo neanderthalensis, and neanderthalensis begat. . . ." Well, as is usually the case with something that simplistic, it wasn't quite that clear-cut. (Which is probably why fundamentalists of any religion have so much trouble dealing with the real world.) Twenty years ago, the idea of interbreeding between subspecies wasn't usually on anyone's radar (at least, not paleoanthropologists), even though we know it happens -- one of my favorite orchids, Cattleya guatamalensis, is a natural hybrid between C. aurantiaca and C. skinneri. There's no reason people couldn't have done the same thing -- and probably would still be doing it, except we don't seem to have any subspecies left.
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