I have a little article in Slate today: “How Strong is a Chimpanzee?”
Last Friday, I noticed a lot of talking-head-type animal trainers claiming that chimpanzees were more than 5 times stronger than people. That just didn’t seem right to me. Chimps are strong, and they have a number of anatomical features that give their muscles more mechanical advantage than ours for certain actions. But 5 times is an awful lot. It would imply some pretty massive changes in muscle histology or metabolism in the human lineage.
Well, it turned out that the story was a lot more interesting than a simple blog post. It goes back to one man’s attempts in the 1920’s to get chimpanzees to pull on a scale. John Bauman isn’t widely remembered today, but he wrote a book of evolution and philosophy called, “Out of the Valley of the Forgotten, or From Trinil to New York.” Bauman got two chimps to pull more weight than his students on the football team. Kroeber, Hooton, and other classic textbook writers picked up the story, but not always pick the subsequent work that showed chimpanzees’ strength to be much less extreme.
The study of muscle tissue in chimpanzees and other hominoids continues, and today there are some interesting genetic results that point to fairly rapid evolution of muscle metabolism in the human lineage. More than any time since the 1960’s, anthropologists are developing more knowledge about why human muscles differ from our closest relatives.