Maybe I was unclear because I was trying not to cause offense.
My question is, How would anyone know that there was a time in human history or prehistory when cats were the #1 predator of human ancestors? (I assume he means the #1 killer of our ancestors that eats us for food.)
maybe I don't get your point (in which case, ignore me), but couldn't you just count the number of deaths by each predator? i.e. count the number of human skeletons with cat teeth stuck in their bones?
