HONG KONG/LEIPZIG, Germany: Modern humans are able to achieve higher bite forces than previously thought, a study from Australia has revealed. In the first comparison of its kind, researchers from the University of New South Wales’ School of Biological, Earth and Environmental Sciences in Sydney found that the slenderly built human skull has a far more efficient bite than that of the chimp, gorilla or orangutan, or that of two prehistoric members of the hominid family, Australopithecus africanus and Paranthropus boisei.

The result calls into question previous suggestions that the evolution of a less robust skull in modern humans involved a trade-off for a weaker bite or was necessarily a response to behavioural changes, such as switching to softer foods or increased processing of foods through tools and cooking. It has also been suggested that human jaw muscles were reduced to make way for a larger brain.

According to the researchers, who used sophisticated 3D finite element analysis to compare digital models of actual skulls, the results might also explain the apparent inconsistency of very thick tooth enamel in modern humans, a feature typically associated with high bite forces in other species.

Thick enamel and large human tooth roots are well adapted to take high loads when biting.