Eve: How the Female Body Drove 200 Million Years of Human Evolution

by Cat Bohannon

The field of research is fairly new, but primatologists have been able to find tantalizing evidence of self-medication. In one case, the medicine in question was the bitter pith and juice from shoots of the Vernonia amygdalina plant. Mahale chimps, sick with parasitic intestinal worms, spend up to eight minutes carefully peeling away the bark and outer layers of the shoots in order to get at the extra-bitter innards. They chew on the pith and suck out its juice. This isn’t tasty. Nearby adult chimps who are not sick avoid the stuff. Primatologists sampled the poo from before and after this pith-eating behavior and found fewer parasite eggs in the post-medication poo. And it just so happens that local humans also had the habit of using this bitter pith in traditional medicine for treating intestinal parasites. As with humans, the chimps presumably learn to treat themselves this way from other chimps.