A new study from researchers at the University of Utah suggests Homo sapiens’ ancestors evolved to take a punch to the face.
The research suggests that violence stemming from male competition for access to mates millions of years ago has influenced the shape of the hominin skull, making it robust in areas it wouldn’t need to be if it had evolved only for eating.
“The face and the head are the most commonly struck targets and those areas of the face that are hit the most are the areas that show the most increase in robustness throughout our evolution,” said author Michael Morgan, an emergency medicine resident at the University of Utah.
Morgan and his co-author David Carrier suggest that earlier theories attributing the thick skulls of our ancestors to hard foods like nuts and seeds don’t explain the extreme robustness seen in many hominin skulls. In fact, the researchers suggest wear patterns on the teeth of our ancestors show that they didn’t have that hard of a diet to begin with.
“The forces that are generated by the jaw and can be imparted to the teeth are much, much higher than we would need to eat,” said Morgan. “We have this structure that if it evolved for eating and eating rough foods that it’s massively overbuilt for that purpose.”
The study points to sexual dimorphism in the skulls of our ancestors, showing the skulls of males and females differ most greatly in the areas that frequently fracture during a fight.
Morgan said he recognizes that his research is controversial, but he hopes it generates discussion.
“We hope that through understanding where we’ve come from and what maybe played a role for us in the past can help us create a more peaceful future,” said Morgan.
The article was published in the journal Biological Reviews.