"Our teeth are made for tearing flesh" - not very efficient with raw flash actually. Raw fish maybe. I've always like the idea we're descended from sea-apes, living in and out of the sea on the beach, sort of cross between mermaids and beachbums.

Animal protein such as worms and insects would be fine too - but raw meat from big animals isn't too easy at all. Chimps have much better sets of teeth than we have, and they can only manage little monkeys.

I always assumed we are designed to eat anything we can get hold of, and most of the things we could get hold of would have been vegetation of one sort or another, because they can't run away.

And anytime there's a forest fire, there'd be cooked meat for a treat, because you could get your teeth round it. So they learned about how to start forest fires. And then some bright spark thought, "Why not do it the other way round - kill the food first and then make make a small fire to make it edible..." And we never looked back.