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http://www.ozy.com/acumen/our-skulls-might-have-evolved-to-withstand-blows-to-the-face/34215?utm_source=CM1&utm_medium=pp&utm_campaign=pp

Prehistoric life really might have been nasty, brutish and short.

Although many scientists believe that a diet of nuts, seeds and other tough, brittle foods shaped our faces, a June study in Biological Reviews suggests that violence had a heavier hand in our evolution. “We suggest that many of the facial features that characterize early hominins” — such as a protruding jaw and thick brow ridge — “evolved to protect the face from injury during fighting with fists,” wrote the study authors, biologist David Carrier and physician Michael Morgan, both from the University of Utah.

The researchers spotted the largest increases in sturdiness in parts of the skull that fracture most often in fights among modern humans.

Carrier and Morgan compared earlier studies’ measurements of the skulls of apes to those of our australopith ancestors — who roamed Africa 2 million to 4 million years ago — and those of modern humans, representing different stages in human evolution. The duo spotted the largest increases in sturdiness in parts of the skull that fracture most often in fights among modern humans, according to studies of assault and domestic violence injuries — namely the nose, brow bone, jaws and cheekbone.

Turns out that these regions also show the starkest size differences between males and females in both australopiths and humans — which makes sense. Males need more protective features, since they’re more likely to fight and suffer slugs to the face. The hypothesis that these regions grew denser in response to diet doesn’t explain the sexual differences; modern-day male and female apes eat pretty much the same food.

The new findings build on Carrier and Morgan’s 2013 study, which suggested that early human hands evolved square proportions and flexible thumbs not only to provide more dexterity for climbing down from the treetops, but also to pummel rivals in fights over territory, mates and other resources. “If the human fist is a dangerous weapon, it is reasonable to predict that the primary target, specifically the head, would have undergone evolution resulting in increased robusticity and protective buttressing,” they wrote.