SSS 2010-08-11（在线收听）

There’s nothing like a good steak. And our Australopithecus afarensis ancestors apparently felt the same way. Because new discoveries from Ethiopia show that what was likely the species of the famous fossil Lucy used stone tools to butcher meat from big mammals—about 3.4 million years ago. That’s a million years earlier than our best previous evidence for human ancestor stone tool use and meat eating. The finding appears on the cover of the journal Nature.

The research team found two fossil bones with cut and scrape marks, signs of meat carving. One bone was a piece of rib from a cow-sized mammal; the other, a leg bone fragment from a mammal the size of a goat. The bones also had percussion marks, sustained while Lucy’s friends smashed the bones to get at the marrow.

It looks like the ancient tool users collected stones that happened to have shapes conducive to butchering, the way kids select particular stones with good potential to skip on water. But future expeditions will look for evidence for any attempts at shaping stones into kitchen utensils. Because after 3.4 million years, Lucy and her fellow afarensis keep surprising us.

Thanks for the minute. For Scientific American's 60-Second Science, I'm Steve Mirsky.