A new, much larger variety of chimpanzee was recently discovered in northern Congo in the Bili region. These chimps walk with their back straight and nest on the ground, unlike other chimpanzees. It's claimed they attack and kill large carnivores for food.

This has renewed the debate among scientists about genetic variation among the great apes. It began in the 1860s when explorer Paul Du Chaillu described a hybrid species he called the koola-kamba -- a cross between chimpanzee and gorilla.

It would seem the great apes exhibit greater variety than was originally believed. Since they inhabit remote, dense jungles, much remains to be learned. They may hold clues about how humans came to emerge. (By Paris A. Walker)