How a 4 million-year-old fistfight
may have formed your face
by Rich Trenholm
CNET.com
Some say the face of human history is shaped by violence, but now scientists say that could be literally true. A new study contends that male faces may look different than female faces because they evolved as protection against a shot to the kisser.
The striking new research suggests that millions of years ago, predecessors to modern humanity evolved bony buttressing for their faces as they fought over females. Females did not evolve such protection.
In the new research, packing a punch in Biological Reviews, University of Utah biology Professor David Carrier and his study co-author, physician Dr. Michael Morgan, enter the ring with data from hospital accident and emergency wards. The data reveals which parts of the face are most frequently damaged in violent confrontations, including the jaw, cheek, eye and nose areas.
Carrier and Morgan argue that australopiths that developed protection for those areas flourished, while those that did not faced serious injury.
"Jaws are one of the most frequent bones to break -- and it's not the end of the world now, because we have surgeons, we have modern medicine," Carrier told the BBC. "But four million years ago, if you broke your jaw, it was probably a fatal injury... You'd just starve to death."
Those with protective buttressing were better equipped when coming face-to-face with another new evolutionary trait: fists. The same team of scientists argues that the hand developed both the capability for sophisticated dexterity and protective buttressing of its own, to transfer more force into a blow struck with a fist than with the open hand. Close relatives of humans such as chimpanzees cannot form a fist.
If true, the theory of facial buttressing would explain why male and female necks and jaws are so markedly different despite the fact we don't fight by biting. Previously, it was believed that changes in jaws and teeth that occurred over time were due to diet. Now it seems that it may not have been nuts and seeds that caused the changes, but a steady diet of knuckle sandwich.
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