“such as eating a deceased relative’s body to prevent it from decomposing.”
I’ll pass. Cremation works just fine.
A story from Herodotus repeating on Free Republic:
"When Darius was king [of Persia], he summoned the Greeks who were at his court and asked them how much money it would take to get them to eat the bodies of their deceased fathers. They replied that nothing would make them do so."
"Darius then summoned some Indians, called Kallatiai, whose custom it is to eat their dead parents, and asked them—in the presence of the Greeks, who had an interpreter to explain the Kallatiai’s words—how much money it would take to convince them to cremate their deceased fathers [as was the Greek custom]."
"The Kallatiai exclaimed that he should not even mention such an abomination. Custom dictates such things, and it seems to me that [the poet] Pindar got it quite right when he said that custom is king.
– Herodotus, Histories 3.38