have we descended from cannibals? A bioarchaeologist and a paleoanthropologist through independent research studies have both established that cannibalism was practised intensively from the early days of human evolution ( Science , Vol 227, No 5326).

In 1967, when bioarchaeologist Christy G Turner II of the Arizona State University found a heap of bones belonging to 30 humans in Arizona, he was taken aback by what he saw. He discovered that the bones of these ancient American Indians had cut marks and burns quite like animal bones that are stripped of flesh that is roasted and consumed. In 1970, Turner wrote in his paper American Antiquity that these people from Polacca Wash, Arizona were victims of cannibalism.

His paper shocked many. "The paradigm about Indians in the '60s was that they were all peaceful and happy. So, to find something like this was the antithesis of the new way we were supposed to be thinking about Indians,' says Turner. The finding was even more startling because the Anasazi were thought to be the ancestors of the Pueblo Indian community. Turner's theory not only debunked the Anasazi cultural tradition but shattered the myth that claims of cannibalism rested on shaky evidence. Archaeologists had earlier seen only the remains of cannibalistic feasts, but researchers today have evidence of bones scarred by ancient burial practices, war, weathering or scavenging animals.

Turner then went about looking for more fossils to see if the Polacca Wash bones were just an isolated incident. Thirty years and 15,000 skeletons later, Turner is putting the final touches on a 1,500-page-book where he says, "Cannibalism was practised intensively for almost four centuries'.

For over a decade, Turner and other bioarchaeologists have been striving to reach a common definition to distinguish between the marks of cannibalism and other kinds of scars. Paleoanthropologist Tim D White of the University of California, Berkley says, "The analytical rigour has increased across the board.'

Archaeologists are now finding what they say are strong signs of cannibalism throughout the fossil record. They are now excavating several sites in Europe where the practice may have occurred among our ancestors, perhaps as early as 800,000 years ago. More recently, the Neanderthals, may have eaten each other. But this behaviour was not limited to the distant past for new evidence suggests that in addition to the Anasazi, the Aztecs of Mexico and the people of Fiji also ate their own kind as recently as 2,500 years ago.

White feels not much research has been done on cannibalism. In 1981, he came across a massive skull of an early human ancestor in Bodo, Ethiopia. When White took a close look at this 600,000-year-old skull, he noticed a series of fine, deep-cut marks on its cheekbone and inside its eye socket, as it had been defleshed. White also discovered that the marks of cannibalism were different from damage by animal gnawing, trampling or excavation.

Turner and his wife, Jacqueline Turner, who had been studying prehistoric bones in museums and private collections in the us and Mexico discovered a pattern of bone processing in several hundred specimens that showed little respect for the dead. "There is no known mortuary practice where the body is dismembered, the head is roasted and dumped into a pit unceremoniously, and other pieces get left all over the floor,' says Turner.

David DeGusta, a student of White says that he has compared human bones at burial sites in Fiji and at a nearby trash midden from the last 2,000 years. The intentionally buried bones were less fragmentary and had no bite marks, burns, percussion pits, or other signs of food processing. The human bones in the trash midden, however, were processed like those of pigs. "This site really challenges the claim that these assemblages of bones are the result of mortuary ritual,' says DeGusta.

Turner says it is a modern bias to insist that cannibalism is not part of human nature. Many other species eat their own, and our ancestors may have had their own reasons