eli5: How did humans learn that some foods are poisonous when raw but not poisonous after being cooked?

Question

eli5: How did humans learn that some foods are poisonous when raw but not poisonous after being cooked?

In: Biology

Answer 1

First there was Bill, Bob, Amy and Anne. Bill ate a mushroom and died, the other 3 watched him die and then did not eat the mushroom.