Unlocking ancient DNA secrets
Scientists who hope to learn more about mankind's closest prehistoric relative--the Neanderthal--have sequenced the DNA of a cave bear that lived about the same time as the doomed hominids.
The idea is that if the DNA of a 40,000-year-old cave bear could be sequenced, so too could the genetic material of Neanderthals. The research, conducted by scientists with the U.S. Department of Energy Joint Genome Institute, is the subject of an article in Friday's issue of the journal Science.
"Our real interest is in hominids, which include humans and the extinct Neandertal, the only other hominid species that we have to compare with humans," Eddy Rubin, JGI director, said in a statement. "Our nearest living relative is the chimp and that's 5 million years of divergence."
Deriving DNA data from such old remains is problematic because as time passes, remains become increasingly fraught with microbial contaminants. Still, researchers were able to piece together the cave bear's sequence in part using dog DNA. On a genetic level, dogs and bears are 92 percent the same; they diverged about 50 million years ago.
Now, researchers want to use similar techniques to sequence the DNA of the Neanderthal or of the Indonesian Flores Man, aka "the hobbit."
Don't expect any dinosaur reconstructions, though. Researchers note that there's a big difference between working with samples that are tens of thousands of years old and those from the Jurassic period--150 to 200 million years ago.
But apparently 68-million-year-old fossils are pretty useful. At least, they can tell you whether a dino was a boy or a girl. New research being described as groundbreaking has shown that the thighbone of a Tyrannosaurus rex unearthed in Montana earlier this year belonged to a female. The research, too, is featured in Friday's Science. Click here to read National Geographic's take on the news.