Answers needed

[Iroscato]

Interesting. Though, using kuru (the disease) as evidence of the evolution of morality sounds dubious.

Think of it as an incidental evolutionary pressure, and when applied and its effects become apparent, there is a natural trend away from indulging in it. Much as killing someone's child will result in you having the shit murdered out of you by the parent, thereby removing you from the gene pool. Natural mechanisms that, when played out, result in a pattern forming.
I'm not a biologist so I can't really explain it better than that, but I think the gist of the point is solid enough.