Slap Happy!

Hmm, they really seem to get into it. Which reminds me of this study which I saw on Instapundit a few days ago:

Utah research: Human face evolved to take a punch

The human face evolved to withstand being hit by a fist, two University of Utah researchers contend, expanding on their controversial theory that human hands evolved to punch.

A protruding jaw, a thick brow ridge above the eyes, robust bones around the nose and upper jaw and large molars and premolars are defining characteristics of early human ancestors examined by David Carrier and Michael Morgan for a study published Monday in the journal Biological Reviews.

Carrier, a biologist, and Morgan, a physician, link the sturdy bone structures of these hominins to a violent human history, challenging the prevailing theory that the bone structure evolved to help crush a diet of nuts and seeds. "Turns out when humans fight, the primary target is the face," Carrier said. "It’s what people strike at. The vast majority of the injuries that occur in fractures [from interpersonal violence] are localized in the face."

The coauthors chiefly focused on the anatomy of skulls from a type of hominin that dates back 2 million to 4 million years ago in eastern Africa. "The teeth were very big," Carrier said. "The mandible and the bones of the upper jaw become more stout, more robust. They’re thicker; they’re bigger."

The jaw muscles would have absorbed some of the energy of a punch and reduced the risk of fracturing or dislocating the upper and lower jaws, their study said. "The activation of the jaw and neck muscles stiffens the connection between the head and body, decreases acceleration of the brain upon impact and therefore reduces the risk of concussion," their study said.

Morgan said it makes sense to develop structural traits to protect the most valuable human asset — the brain. And the skeletal structure of the face was too large to develop for diet alone, they contend.

Wombat-socho has the great "Rule 5 Tuesday – Belated Independence Day Weekend Edition" up at The Other McCain.