Less energy needed to eat sliced raw meat led to smaller teeth, jaw
Chip Clark, Smithsonian Human Origins Program
Early members of the human genus had a flair for preparing sliced wild game tartare, a new study suggests. That meaty diet may have literally changed the face of Homo evolution, and enabled advances in talking and walking.
By 1.8 million years ago, Homo erectus sliced up raw meat with stone tools before eating it, say Harvard University paleoanthropologists Katherine Zink and Daniel Lieberman. It was a momentous move, making it possible to consume more calories while reducing chewing effort, the researchers report online March 9 in Nature. Faces and jaws got smaller while an energy-rich diet allowed brains and bodies to enlarge.
Evolutionary shrinkage of bones and muscles involved in chewing affected other parts of the body, the scientists say. An expanded vocal tract boosted the ability to make speech sounds. And a repositioned spinal cord, resulting from realignment of the base