Interesting theory. I’ll put this as my title on my new business cards: “Hot-day Meat Chaser”
Our “sustainable distance” is also hard to beat. African hunting dogs typically travel an average of 10 kilometers a day. Wolves and hyenas tend to go about 14 and 19 kilometers, respectively. In repeated distance runs, horses can cover about 20 kilometers a day. Vast throngs of human runners, by comparison, routinely run 42.2-kilometer marathons in just a few hours, and each year tens of thousands of people complete ultra-marathons of 100 kilometers and longer. (A few animals can match that under special circumstances. Huskies can trot up to 100 kilometers in Arctic conditions when forced to by people. But in warmer climes—no way.)
But how did we get this way? After all, our brainy, tool-using ancestors could have just sneaked up on prey animals and brought them down with a spear or arrow. Why did evolution shape us as great distance runners?
The answer, argue Lieberman and Bramble, is that snares, nets, and really effective projectile weapons, such as the bow and arrow, were probably invented by Homo sapiens—modern humans. There’s no evidence that early Stone Age hunters had weapons much better than sharp sticks. Such armaments would have required them to kill prey animals at close quarters, where they would have been at high risk of getting fatally gored, bitten, or kicked. Thus, they probably obtained meat mainly via “persistence hunting”—chasing an antelope, for instance, until it was nearly keeling over with heat exhaustion—and scavenging. The latter was very much a running game: When distant, circling vultures tipped them off about a lion kill, they had to get there before hyenas, which strip everything edible from carcasses. And they typically could only outrace hyenas in the hot sun. As a result, they carved out a new carnivore niche: the hot-day meat chaser.