Male Male Competition and Female Mate Choice

In most animal species, males will compete for females and any resources that females need and want. Males getting those things, but doing it through violence or the threat of violence against other males has been an issue in human evolution too. So male who can handle himself either get a reputation as the guy you don't fuck with or get a group of guys around you who are intimidating enough that nobody fucks with you. Or you simply raid the other clans and eliminate your rivals.