Question

What evidence is there that chimpanzees in the wild use Vernonia amygdalina to treat parasitic infestations? Do you agree with the hypothesis that wild chimps self-medicate? Why or why not?

Answer 1

(1) the animal should show signs of illness;
(2) it should seek a substance that is not part of its normal diet and has no nutritional value;
(3) the animal’s health should improve;
(4) laboratory analysis of the substance should establish that enough active ingredients have been ingested to bring about the changes observed.

All the conditions listed above have been demonstrated for wild chimpanzees infected with internal parasites. Chimpanzees suffering from parasite-related diseases eat the bitter pith of the plant Vernonia amygdalina, which contain anti-parasitic compounds and is eaten by chimps at doses high enough to combat parasites.