Why do we humans practice monogamy ?
To conserve energy and two make our rather helpless children have more than one parent
It didn’t come to be. “Monogamy” - ie people who marry as virgins and remain faithful til they die $nhas always been a small minority of human sexuality. In reality, the commonest pattern of human sexuality is a series of nearly-monogamous relationships with whatever else opportunity makes available. Fact.
The second prediction that follows from Trivers' theory is that the fact that women invest more heavily in offspring makes them a valuable resource for males as it ensures the survival of their offspring which is the driving force of natural selection. The risks for males are higher because although women invest more in their offspring, they have bigger maternity certainty because they themselves have carried out the child. However, males can never have 100% paternal certainty and therefore risk investing resources and time in offspring that is genetically unrelated. Evolutionary psychology views jealousy as an adaptive response to this problem.
It’s just to control the population