Apes are mostly polygamous though. And even if polygamy wasn't the norm culturally, the results of procreation have been polygamous. For example this study anal

Apes are mostly polygamous though. And even if polygamy wasn't the norm culturally, the results of procreation have been polygamous. For example this study analyzed dna and shows how 8,000 Years Ago, 17 Women Reproduced for Every One Man. https://psmag.com/environment/17-to-1-reproductive-success https://psmag.com/environment/17-to-1-reproductive-success