The 30-ish Oliver, 1.2 meters high and 50 kilograms, arrived from Western Africa about 25 years ago. Impressed into the animal show circuit, he caused viewers to marvel at his upright posture, his small head-which, shaved, had an eerie humanoid quality-and his unusually rank odor. It was said that he could cry, and could not only mix drinks but spot when people needed refills. Other chimps didn't seem to care for him, which added to his mystique.

Oliver sank out of sight in the '80s, spending some unemployed years at a Pennsylvania research animal supply company. Last spring, he was retired to Primarily Primates, a reservation near San Antonio, run by "primate rehabilitator" Wally Swett.

Now Oliver is garnering a few more headlines thanks to Gordon Gallup, a professor of evolutionary psychology at the State University of New York, Albany, who says he's been fascinated by the creature ever since he first read about him in 1976. Gallup has arranged for medical geneticist David Ledbetter of the University of Chicago to have a good look at Oliver's chromosomes and find out if he's "nothing more than a mutant chimpanzee" or something more interesting-a hitherto unknown combination of chimp and bonobo (pygmy chimp), a brand-new subspecies-or, yes, even a "humanzee."

There have been vague reports that Oliver's chromosomes were once counted in Japan and came to 47-exactly between the 46 for humans and 48 for chimps-but Ledbetter says he has no doubt that it will be 48: "Then the question will be is there any other explanation for why he's unusual."

Primatologist Steven Suomi of the National Institute for Child Health and Human Development says Oliver doesn't sound like anything special; rather, the reports of his small head and high-pitched vocalizations are consistent with his being a bonobo. But at least one expert-primatologist George Schaller, who examined Oliver in 1976-has adjudged his unusual posture, which includes standing with shoulders back and knees locked, to be "well worthy of study."