The last of the woolly mammoths in Siberia died out about 10,000 years ago, but a smaller number living on Wrangel Island, off the coast of what is now Russia, managed to stick around for another 6,000 years. Researchers set out to investigate the two groups and the species' ultimate demise, and in the process sequenced the animal's entire genome "in what may be a first for a long-extinct non-human animal," the Los Angeles Times reports. While the BBC reports the genome could help those attempting to bring the beast back to life, study researchers were more interested in what it revealed about the animal's decline—specifically, that the mammoths suffered two major population declines around 280,000 years ago and 12,000 years ago; the last one left fewer than 1,000 remaining, Reuters reports. The genome also revealed evidence of inbreeding, beginning 5,000 years before the mammoth went extinct.
Researchers analyzed DNA from the soft tissue of a young male mammoth that lived 44,800 years ago in Siberia, plus that from a 4,300-year-old molar from a male mammoth on Wrangel Island. Though the two DNA copies from the Siberian mammoth—one from the mother's side, one from the father's side—showed strong genetic variation, the Wrangel Island mammoth's genetic diversity was much lower. In fact, its parents were probably related and the mammoth population quite small. The research doesn't prove low genetic diversity will push an animal to extinction or that it did in the case of the woolly mammoth, but an evolutionary biologist compares a genome to a "tool kit for getting out of trouble." Greater genetic variation means a species has more tools to fight off disease or environmental changes. "If you don't have the diversity, it's a challenge." (Oil workers recently pulled up a mammoth tusk.)