Australian researchers have found that the human skull has a far more efficient bite than those of the chimp, gorilla and orangutan.
The team, which included Dr Colin McHenry from the University of Newcastle and was led by Dr Stephen Wroe of the University of New South Wales, used 3D analysis to compare digital models of CAT-scanned skulls.
The analysis showed that humans are efficient and powerful biters, despite having relatively light skulls and small jaw muscles.
Dr McHenry said the study questioned previous suggestions that the evolution of the human skull was a trade-off for a weaker bite.
"It has been argued that a lightly built human skull was the result of humans eating softer foods or processing foods with tools and cooking. It has even been suggested that human jaw muscles were reduced to make way for an increase in brain size.
"This study suggests that ancestral humans were able to eat hard foods. We hope this outcome will lead to more research into the feeding mechanics of early humans."
The research is available in the early online section of the journal Proceedings of the Royal Society B.
Read the paper on the Australian Geographic website