And really, what kind of evolutionary strategy would it be if they did? I mean c’mon…… All of this “survival of the fittest” crap is really nineteenth-century political theory that got absorbed by Darwin. Manifest destiny sounds good to greedy colonizers but in actuality, organisms that cooperate have the greatest reproductive fitness, meaning that their offspring live long enough to also reproduce.
The currently more widely accepted theory is that early humans were cooperative breeders, meaning that women mated with several men and the group all took care of each other, including all children, regardless of parentage (which would have been unable to be verified at that time anyhow). It’s only when patriarchy comes along several hundred thousand years later and women’s sexuality is able to be policed and controlled, that paternity is able to be somewhat known.