The patas monkey is an Old World Monkey,
as is the colorful mandrill (right) and the
red-faced Japanese macaque  (grooming pair, right).

The default expression of each of these three monkey species is "expressive" in the manner of a painting, but it is not versatile in the manner of the great apes.

Even in the lesser apes, one seldom sees the postures and facial expressions, so reminiscent  of humans, that are frequent in the great apes (gorillas, orangutans, chimpanzees, and bonobos).

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There used to be many species of apes, but most are now extinct. The remaining apes live quite close to the equator, in either Africa or southeast Asia and its offshore islands.  All are rapidly disappearing in the wild, endangered by timber cutting and hunting.  Viral disease has been quickly reducing ape populations in Central Africa.

Our closest relatives are the chimps and bonobos, with whom we shared a common ancestor about 6 million years ago.  (Gorilla 8, orangutan 12, lesser apes 18.)

Recent books by the photographer:

A Brief History of the Mind 2004

A Brain for All Seasons 2002

Lingua ex Machina 2000

William H. Calvin is a neurobiologist at the University of Washington in Seattle who wanders regularly into anthropology, evolution, and climate change.  He won the Phi Beta Kappa 2002 Book Award for contributions to literature by a scientist.