Yes, chimpanzees – our genetic near-relatives – have an alpha caste who enforce sexual restrictions through violence…but we’re a social hierarchy – are matriarchal, with relative status determined by age rather than muscle and violence.
Sex amongst bonobos is a free-for-all; males and females have equal access to one another and participate in sex regularly with both troop members and apes from other social groups.
The alpha alone gets to pass along his genes; many apes – chimps and gorillas especially – will outright mating patterns (humans, after all, are just hairless apes), the idea is that women are naturally attracted to alpha males – dominant, powerful, high-status men – while disdaining the weaker, less dominant betas.
It’s an appealing idea in many ways; it provides the gloss of an appeal to nature- it nicely coincides with the macro perception of human sexual interaction and provides justification for promiscuous male behavior and an explanation for hypergamous females. The narrative that men are naturally promiscuous (the better to ensure the survival of their genetic line) while women are naturally monogamous is the result of a cultural fallacy dating back as far as Charles Darwin; scientists and anthropologists of the time tended to use Western cultural morality as the prism through which they viewed natural discoveries – a problem that occasionally crops up today, as a matter of fact.
In fact, the idea of sexual exclusivity – of humans being concerned with genetic lineage and trying to avoid raising another man’s child – is a relatively recent development, evolutionarily speaking.
Amongst primates that live in social groups (baboons, chimpanzees, gorillas), the largest, strongest of the male apes is the alpha male; the others are betas.
The alpha rules the pack by dint of his strength and furious violence; he gets the greatest amount of food and unlimited sexual access to the females.