The 111th Boston Marathon was run on Monday, in rather dismal conditions. A few days before, anthropologist Daniel Lieberman delivered an interesting talk on why it is that humans, alone among terrestrial animals, and certainly alone among mammals, can and do run so far. His talk is summarized at Physorg.com. A few snippets:
Lieberman said the appearance about 2 million years ago of physical adaptations that have no impact on walking but that make humans better endurance runners provide evidence that early scavengers became running hunters.And then, hey, no need to cook Mr. Antelope! He's half cooked already.
Specifically, we developed long, springy tendons in our legs and feet that function like large elastics, storing energy and releasing it with each running stride, reducing the amount of energy it takes to take another step. There are also several adaptations to help keep our bodies stable as we run, such as the way we counterbalance each step with an arm swing, our large butt muscles that hold our upper bodies upright, and an elastic ligament in our neck to help keep our head steady...
Humans, he said, have several adaptations that help us dump the enormous amounts of heat generated by running. These adaptations include our hairlessness, our ability to sweat, and the fact that we breathe through our mouths when we run, which not only allows us to take bigger breaths, but also helps dump heat. "We can run in conditions that no other animal can run in," Lieberman said.
All together, Lieberman said, these adaptations allowed us to relentlessly pursue game in the hottest part of the day when most animals rest. Lieberman said humans likely practiced persistence hunting, chasing a game animal during the heat of the day, making it run faster than it could maintain, tracking and flushing it if it tried to rest, and repeating the process until the animal literally overheated and collapsed.
The talk on the whole a fascinating look at how anthropology can help make sense not only of human origins and capacities, but some of the wacky shit we do - like run 26.2 miles in a rainstorm.
(The summary also quotes a silly thing Lieberman said: "Humans are terrible athletes in terms of power and speed, but we’re phenomenal at slow and steady. We’re the tortoises of the animal kingdom." I guess that's why he's an anthropologist and not a biologist.)