February 3, 2009

Survival shaped face of human ancestors

A U.S. researcher says the facial structure of our early human ancestors appear to have evolved to allow them to eat large, hard nuts to survive.

Dennis Slice of Florida State University said the findings, published in the journal Proceedings of the National Academy of Science, challenge the hypothesis that the facial skeleton of Australopithecus africanus was developed for feeding on small objects.

The face of the early human relative, who lived in Africa more than 2 million years ago, had columns of bone positioned along either side of the nasal cavity that acted as struts to reinforce the face, the university said Tuesday in a news release.

An international team of researchers found A. africanus might have used bicuspids and a structurally reinforced face to crack open and ingest large, hard nuts and seeds during periods when preferred, softer foods were in short supply.

It is possible that their facial architecture was driven not by their day-to-day activities but by their capacity to survive hard times by switching to what are called 'fallback foods,' Slice said.