This struck me while eating my beef this afternoon. How long have we been eathing meat? Raw meat isn't really easy to chew and it doesn't really taste that good, plus it has a lot higher chance to spread different types of diseases., so did we eat it even though it was raw before we found out that you can actually cook it?
You will definitely want to ask anthropologists about this. As I understand it there is currently a big debate as to how long ago hominids began to use fire to cook and if, indeed, homo sapiens (modern humans) actually evolved because some earlier hominid began to use fire to cook their food. That is to say, we might be humans precisely because our forefathers began cooking with fire.
It's a fascinating topic and only a real anthropologist debate will get you the latest info on it.
You might also wish to submit this to /r/AskAnthropology.