Did Cannibalism and Spongiform Encephalopathy Contribute to the Demise of the Neanderthals?

Abstract

There is palaeological evidence that Neanderthals ate the brain tissue of their own deceased as well as that of deer and goats. This would expose each participating individual to the risks of contracting an animal spongiform encephalopathy. Those who consumed the remains of infected individual's would then contract a form of the disease and eventually infect others. If that occured, then the Neanderthal diet could have contributed to their eventual demise. Key Words: Neanderthals, spongiform encephalopathy, kuru, human evolution, Scrapie, cannibalism, chimpanzees As Azar Gat has observed in this journal, the reason for the demise of the Neanderthals is still a mystery. In a subsequent issue, Goodhart has postulated that the Neanderthals, and other populations of Homo erectus, retained the 24 pairs of chromosomes characteristic of chimpanzees and gorillas. In this case, mating with Homo sapiens would probably not have produced fertile offspring. Goodhart then ascribed their disappearance to an inability to compete with the socially more advanced Homo sapiens. Gat also adduces a social distinction, by postulating significantly smaller tribal groupings among the Neanderthals, with consequent inability to wage warfare cooperatively on a large scale. Other theories, reviewed by Gat, include less efficient Mousterian tools, looser family structure, inferior planning ability, and weaker linguistic capability. I now present another more damaging Neanderthal social trait, which could well have curtailed their continued existence. Although the Neanderthals have been assumed to have been hunter-gatherers, there is evidence that they subsisted almost entirely by hunting. Richards et al. report an isotope analysis of Neanderthal bone collagen, indicating that they were top-level carnivores who obtained almost all of their dietary protein from animal sources. The first evidence that they were also cannibals appears to have been found in a rock shelter near the Krapinica River in Croatia. Here, skeletal fossils of at least 13 adults and children revealed skulls, teeth and post-cranial bones that had Neanderthal features. The remains were estimated to belong to the last glacial period, about 40,000 to 75,000 years ago. The fragmented state of the skulls, together with evidence of charring, suggested that the extracranial tissues and the brain had been cooked and eaten. These findings were reported by D. Gorjanovic-Kramberger in 1906, but a more recent report came from DeFleur et al. in 1999, and concerned excavation of a cave site near the River Rhone in south-eastern France. Here both human and animal (mainly deer) skeletal remains were uncovered and the human remains appeared to be Neanderthal. Both the human and animal skulls were in fragments and the exterior of both bore the same pattern of incised grooves indicative of defleshing. The report concludes from the fractured state of both skulls and other bones that the brains and marrow had been extracted for consumption. The authors note that cannibalism has been attributed to the Neanderthals for about a century, and give six other references of findings similar to their own. A present-day people who until recently ate human brain are the Fore people of Papua New Guinea. They performed this cannibalistic act as part of a mourning ritual, in which the brain of the deceased relative was handled and then eaten. The Fore suffered an endemic disease known as Kuru, because of its symptom of trembling, which is kuru in the Fore language. It is a rapidly progressive brain disease that is usually fatal within two years of onset. Kuru is one of the spongiform encephalopathies, in which the brain develops a spongy appearance due to the development in it of multiple small cavities. The pattern of incidence suggested a transmissible rather than hereditary disease. An American physician proved this by injecting samples of brain tissue from a sufferer into chimpanzees, who developed the same disease. …