“In the ancient Olympics, nobody competed with shoes, you would run barefoot.”
— Daniel Lieberman, evolutionary biologist
Forget the invention of sex, fire, toolmaking, language, agriculture. The real turning point in the four-billion-year saga from the origin of life on Earth to bacon-flavored dental floss occurred 7 million years ago, a blink of a geological eye. That’s when we split off from the chimpanzee lineage and became fully bipedal. Walking on two legs, the most natural of human activities (other than checking our Facebook likes) was born when the African rainforests started to disappear in response to massive climate change. Instead of the rich dining opportunities presented by a fertile and fecund forest, our ancestors were born into a woodland in which food was more limited and more scattered; to survive, you had to roam farther afield.
In this environment, the ability to walk upright, rather than knuckle-walk (like chimps) was an adaptive advantage just waiting to happen. Not only is knuckle-walking slower than upright walking, but it’s an expensive way to get around: Pound for pound, it’s about twice as energy-draining as walking upright. Chimps, of course, are much better at climbing trees, thanks to their long arms, but much worse at getting from point A to point B on the ground. So natural selection promoted this new upright species, given the cumbersome name Sahelanthropus tchadensis by anthropologists.
That’s walking. How about running? That had to wait another 5 million years, when another climate shift morphed our ancestors’ African home from woodland to savannah grasslands, bringing with it a change of diet. Formerly, they were mostly vegetarians — fruit, nuts and tubers — with the occasional scavenged animal carcass to add to the mix. But now our forebears had to find another food source: animals. The picture painted by anthropologists is confused and controversial, but most believe that, with the disappearance of woodland, early hominids adapted to running. Here’s what they do agree upon: Our ancestors ran slower than most of the prey they hunted but, critically, they could outlast them. Chasing animals to exhaustion, they were able to finish them off them with rocks or clubs and nourish themselves on nutrient-rich protein.
One key finding from 2 million-year-old fossil evidence is the discovery of skeletons wonderfully adapted to running, including arched (“springy”) feet, short toes (unlike 3 million-year-old “Lucy”), and a big butt. The latter — formally our gluteus maximus (which leaves a scar on a fossilized pelvis) is the muscle that stabilizes our upper body, especially when we run. We went from walkers to runners.
Shoes, of course, came later. Evolutionist Daniel Lieberman, quoted above, has made a study of what the invention of shoes, perhaps 40,000 years ago, has cost us. “When you wear shoes, you lose a lot of [sensory] information,” he said in an interview for Discover magazine. “People who are barefoot tend to have really healthy feet in terms of strength. … In the barefoot populations we study, almost nobody has flat feet.” Unlike about one-third of Americans.
Lieberman, “the barefoot professor,” walks his talk — actually, runs his talk, having competed in the Boston Marathon 11 times either barefoot or in minimal footwear. He was featured in Chris McDougall’s bestseller Born to Run, the book that brought the long-distance running abilities of Mexico’s Copper Canyon Tarahumara tribe to the attention of the world. These Indigenous people, wearing no or minimal shoes, land on their forefoot, a technique that maximizes running efficiency.
For the first time in our evolutionary history, we humans aren’t routinely walking and running. Between automobiles, desk-bound jobs and social media, we’ve gone from active to sedentary in the space of a generation or two. Makes you wonder what kids’ feet will be like 100 years from now.
Barry Evans (he/him, barryevans9@yahoo.com) plans to keep up his 10K steps per day as long as he can. Wearing runners.
This article appears in Forgotten In Rio Dell.