Human hand may have evolved to throw a punch

The whole notion started as an argument. Controversial researcher David Carrier had suggested that sperm whales — specifically, their foreheads — evolved to serve as battering rams. One of Carrier's friends very much disagreed with that notion, and the two got into an argument. At one point, Carrier's friend put up a fist and announced, "I can hit you in the face with this, but that's not why it evolved!" Such a idea, though, didn't seem so far-fetched to Carrier.

That altercation took place a decade ago. Now, the University of Utah biologist is behind a newly published study that suggests the human hand evolved in order to throw a punch — or, more actually put, for form the fist, which then delivers the punch. He tested the idea using cadaver arms, among other things.

This isn't Carrier's first study on whether the human hand evolved because of — and to be better at — throwing punches. He remains controversial, as do his studies, but that hasn't slowed him down. Taking it a step further, Carrier also suggests that the human face's shape could have itself evolved to better handle being pummeled with a fist.

The going belief is that human hands evolved their distinct shapes in order to better hold tools. That makes sense, and is widely accepted, whereas the notion that humans fighting had a contributing factor is not. Still, Carrier says "we're suggesting ... that maybe there's another component."

In this latest study, Carrier and his team glued transducers onto the bones of cadaver hands. Fishing line was then tied to the tendons in the limbs, and the limbs themselves were hoisted onto a platform. Oddly enough, the fishing line was attached to guitar tuners. The researchers would "tune" the tendons to a specific tightness (making a fist), then swing the platform so that the fist collided with something (e.g., throw a "punch").

As it turns out, the human fist can punch with 55% more force than one could deliver with an open handed slap. Whether that ability evolved because of humans' habit of fighting is another matter.

SOURCE: Washington Post