William Saletan in Slate:
Last week in Nature, scientists reported major progress in sequencing the genome of woolly mammoths. They reconstructed it from two fossilized hair samples. One was 20,000 years old; the other was 65,000 years old. Now, according to Nicholas Wade of the New York Times, biologists are discussing “how to modify the DNA in an elephant's egg so that after each round of changes it would progressively resemble the DNA in a mammoth egg. The final-stage egg could then be brought to term in an elephant mother.”
Cool, huh? But that's not the half of it. Wade notes:
The full genome of the Neanderthal, an ancient human species probably driven to extinction by the first modern humans that entered Europe some 45,000 years ago, is expected to be recovered shortly. If the mammoth can be resurrected, the same would be technically possible for Neanderthals.
In fact, Wade points out, there are good reasons to re-create a Neanderthal: “No one knows if Neanderthals could speak. A living one would answer that question and many others.”