Mastodon Genome Sheds Light on Human Evolution

 From NewScientist.com
24 July 2007

An analysis of genetic material painstakingly retrieved from an ancient mastodon tooth has pushed back the date that mammoths diverged from elephants by about 2 million years.

The finding pegs the mammoth and elephant split to sometime around 6 million to 7 million years ago, when humans and our primate relatives may have last shared a common ancestor. Researchers say this makes it more likely that
environmental changes at the time caused a massive period of speciation in Africa.

Until recently, scientists believed that humans and chimps last shared a common ancestor about 5 million years ago, says Paul Matheus at the University of Alaska in Fairbanks, US. But he adds that fossil studies and genetic discoveries in recent years have pushed this date back by at least 1 million years.

Now, with the help of a mastodon tooth recovered in Alaska, Matheus and his colleagues say the same sort of revision might take place for the evolutionary history of mammoths and elephants, which were previously thought to have diverged from one another about 5 million years ago.

Journal reference: PLoS Biology (DOI: 10.1371/journal.pbio.0050207)

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