US: Our ancient ancestors may have tucked into something akin to the Atkins high protein diet. The result was not weight loss but a competitive advantage over other animals chasing scarce meat supplies.
An intriguing version of what our ancestors fancied for dinner was presented yesterday at the AAAS meeting in Washington. It suggests that early humans living alongside great apes millions of years ago could have gained an evolutionary advantage by skipping carbohydrates and adding fatty meat to their menu.
Part of the theory comes from a nine-year field study of gorillas living with chimps in Uganda. It showed that our great ape relatives, far from being docile leaf eaters, would compete actively with the chimps for limited meat supplies.
If our ancient ancestors did in fact begin lashing into antelope steak or wildebeest stew, then their increased meat consumption could have triggered genetic changes.
Evolutionary selection would have allowing them to eat more fatty foods without developing heart disease, according to Prof Caleb Finch of the University of Southern California.
Increased protein consumption would have made them stronger, fitter and faster, giving them an edge over their vegetarian neighbours. Analysis of fossil molars provides some evidence of how this assumption could be true.
Tool use and cooking made it much easier to eat our food, but also reduced the evolutionary requirement for large, powerful teeth and jaws, according to Prof Peter Lucas of George Washington University.
This in turn led to facial dwarfing with smaller jaws, but unfortunately with a similar number of teeth.
This produced the dental crowding and crooked teeth we see today, with jaws unable to accommodate the wisdom teeth we no longer require to survive.