The introduction of anisogamy has caused males and females to tend to have different optimal mating strategies. This is because males may increase their fitness by mating with many females, whereas females are limited by their own fecundity. Females are therefore typically more likely to be selective in choosing mates.Avise, J. C., Liu, J.-X., & Avise1, J. C. (2010). Multiple mating and its relationship to alternative modes of gestation in male-pregnant versus female-pregnant fish species. Source: Proceedings of the National Academy of Sciences of the United States of America, 107(44), 18915–18920. https://www.jstor.org/stable/25748596 Monogamy is suggested to limit fitness differences, as males and females will mate in pairs. This would seem to be non-beneficial to males, but may not be in all cases. Several behaviors and ecological concerns may have led to the evolution of monogamy as a relevant mating strategy. Partner and resource availability, enforcement, mate assistance, and territory defense may be some of the most prevalent factors affecting animal behavior.
