Widespread prehistoric human cannibalism: easier to swallow?

There is increasing evidence that cannibalism, formerly thought to be a rare and/or ‘abnormal’ human behaviour, was practiced widely by our ancestors. Support for this contention comes from a new paper by Mead et al. that finds evidence for balancing selection at the prion protein gene in human populations, which might have been driven by past epidemics of prion diseases (such as kuru) that were transmitted via cannibalism.