What tree-climbing pygmies tell us about foot evolution


At some point in human history, our ancestors descended from the trees and started walking permanently on two legs. In the process, our feet evolved from the grasping appendages of other apes into sturdy levers. We lost an opposable big toe, our ankles became stiffer, and our bones formed an arch that runs from our ankle to our toes. We sacrificed the ability to grip in return for a springy, shock-absorbent step.

These changes were already in place 3.5 million years ago. One of our ancient relatives, Australopithecus afarensis, had a remarkably human foot and was clearly already walking around on two legs. Some scientists have taken this to mean that hominins such as Lucy (the most famousA.afarensis specimen) necessarily walked on the ground. After all, human feet are supposedly ill-suited for life in the trees.

But try telling that to the gentleman in the video below. He’s one of theTwa pygmies—a group of Ugandan hunter-gatherers who often climb trees in search of food, such as honey and fruit. Like other Twa men, he started from an early age. And he’s clear proof that a human foot is no impediment to walking straight up a trunk.

The footage was shot by Vivek VenkataramanThomas Kraft andNathaniel Dominy from Dartmouth College. The trio originally started studying the Twa to understand the evolution of their short five-foot stature but were awestruck at how adeptly they could climb. “We tried to climb the same trees, but we found it extremely difficult,” says Venkataraman. “The Twa were quicker, more agile, and highly coordinated.”

Written By: Ed Yong
continue to source article at phenomena.nationalgeographic.com


  1. ” long arms, curved fingers, and ape-like shoulder blades “

    Compare the pictures of the man and chimp going up the tree and you can almost see it happening so long ago.

  2. The ability to tolerate bee stings without flinching is another impressive capability. Especially at that height where a fall could be fatal.

    Bee hives would presumably be well-dispersed. So bipedal adapted feet might be a good compromise to get around the hives as well climb up to steal the honey.

    There’s some residual human instincts for trees. If you take young kids to a park with some trees, some wide open space, and a pond. Then the kids will almost certainly climb the trees. But they’re less likely to run to the far end of the wide open space, or swim in the pond. (Unless there are footballs involved or it’s very hot.)

  3. There is a size an weight issue here, which could explain the pygmy stature.
    It is noteworthy that large dominant male apes, cannot climb as well as smaller youngsters. – Which reminds me that I was quite adept at climbing trees as a child. Now I need a ladder!

  4. Obviously the pigmies have a big advantage over the researchers in terms of experience and practice.

    It would be very interesting to see how well a top class rock climber would compare to the pygmies.

  5. I’m underwhelmed, would hardly call that scampering. Wonder if the researchers tried taking their shoes off.

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