Only about 5 million years ago human beings and chimps shared a common ancestor, and we still have much behavior in common: namely, a long period of infant dependency, a reliance on learning what to eat and how to obtain food, social bonds that persist over generations, and the need to deal as a group with many everyday conflicts.
The assumption has been that chimp behavior today may be similar to the behavior of human ancestors.
Primatologists are beginning to study the bonobos' unrestrained sexual behavior for tantalizing clues to the origins of our own sexuality.
In reconstructing how early man and woman behaved, researchers have generally looked not to bonobos but to common chimpanzees.
The two females rub their genitals together, grinning and screaming in pleasure. It doesn't even involve people—or rather, it involves them only as observers.
Lana, Maiko, and Lina are bonobos, a rare species of chimplike ape in which frequent couplings and casual sex play characterize every social relationship—between males and females, members of the same sex, closely related animals, and total strangers.
In another, a teacher walks into a classroom and shortly after she leaves, the camera focuses on a boy's crotch. Chris J Botha principal Hagan Godfrey said he was "disgusted" and disciplinary measures were being taken against the 18 pupils related to the video.
15 at Theatre Vertigo, makes Meg Ryan's expertly faked ecstasy look like child's play.
Bonobo behavior, however, offers another window on the past because they, too, shared our 5-million-year-old ancestor, diverging from chimps just 2 million years ago.
The British hunk indicated that he and several other key cast members have parted ways with the US series after it was announced that the fourth and final movie will be a TV movie rather than a cinematic release.
The video clip also shows a wild party in the boys' bathroom and a teacher who appears to be sleeping on a desk.
In one scene, a pupil is seen standing on a teacher's desk with the words "Grandma is not here" appearing above his head.