A Neanderthal-eat-Neanderthal world may have spread a mad cow-like disease that weakened and reduced populations of the large Eurasian human, thereby contributing to its extinction, according to a new theory based on cannibalism that took place in more recent history.

Aside from illustrating that consumption of one's own species isn't exactly a healthy way to eat, the new theoretical model could resolve the longstanding mystery as to what caused Neanderthals, which emerged around 250,000 years ago, to disappear off the face of the Earth about 30,000 years ago.

"The story of Neanderthal extinction is one of the most intriguing in all of human evolution," author Simon Underdown told Discovery News. "Why did a large-brained, intelligent hominid that shared so many traits with us disappear?"

To resolve that question, Underdown, a lecturer in the Department of Anthropology at Oxford Brookes University, studied a well-documented tribal group, the Fore of Papua New Guinea, who practiced ritualistic cannibalism.