Fight Club: Research Says Violence Shaped Human Face

Fist fights might have shaped human faces, a new study suggests.

According to University of Utah scientists and colleagues, human faces - especially those of australopith ancestors - evolved to minimize damage during fist fights.

Face is attacked the most during a fist fight. Today, doctors can treat a jaw injury. "But four million years ago, if you broke your jaw, it was probably a fatal injury. You wouldn't be able to chew food... You'd just starve to death," said David Carrie, University of Utah physician, to BBC.

The research challenges the idea that human face evolved to help us eat hard-to-crush foods such as nuts.

Researchers said that human ancestors evolved the facial features at almost the same time as their hands allowed them to make a fist. Also, the team found that parts of face that suffered the greatest damage during a fight are also the ones that have shown the greatest rigidity. The study explains why male faces are so different from female faces.

For the research, scientists looked at the evolution of genus Australopithecus, which are the immediate predecessors of genus Homo. Understanding anatomical features in Australopithecus helped scientists find why we look the way we do.

"The australopiths were characterized by a suite of traits that may have improved fighting ability, including hand proportions that allow formation of a fist; effectively turning the delicate musculoskeletal system of the hand into a club effective for striking," said Carrier, lead author of the study.

"If indeed the evolution of our hand proportions were associated with selection for fighting behavior you might expect the primary target, the face, to have undergone evolution to better protect it from injury when punched," Carrier said in a news release.

The new study builds on earlier research by Carrier and colleagues that tried to find how violence shaped human evolution. According to researchers, hand and leg proportion and even bipedalism is associated with humans' fighting abilities. Their previous research on hand proportion has received a lot of criticism.

Human faces aren't as rugged as they were during Australopithecus' time because human arms gradually weakened. "Our arms and upper body are not nearly as strong as they were in the australopiths," Carrier explained, according to BBC. "There's a temporal correlation."

The study is published in the journal Biological Reviews.