Two-Million-Year-Old Tooth Widens the Ancient Human Family Tree.

Two-million-year-old teeth (four sets, in fact) tell new stories in a newly posted preprint paper that strips them of enamel and analyzes what the proteins have to say. This "proteomic" approach, which relied on the more rugged protein molecules instead of fragile DNA, revealed their relationship to the wider family tree of early humans.

Taken from a sediment-filled cave in South Africa, the fossilized teeth once formed the dentition of an ancient hominin, Paranthropus robustus.

This species was diminutive by modern standards, measuring about three and a half feet tall, but it was relatively sturdy in build and weighed about 100 pounds. While P. robustus doesn’t appear to have used stone tools, the species did use bones to dig into termite mounds and its large teeth to chew on nuts and other tough foods.

Scientists aiming to organize a family tree for early humans have their work cut out for them. Ancient DNA (aDNA) is notoriously fragile and easily destroyed by groundwater and high temperatures. The oldest ever aDNA recovered from Africa was only about 18,000 years old. Which isn't that ancient considering more sophisticated technologies and cultures began to develop about 100,000 years ago.

In 2010, researchers announced that they had sequenced a 400,000-year-old Neanderthal genome from a specimen found in Spain, the oldest example of hominin aDNA to date. But this was a rare feat and only a small part of the tree. Bipedalism first arose some 4 million years ago, and the important human predecessor Homo erectus evolved about 2 million years ago.

Source: www.discovermagazine.com

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