Sexual bimaturism

Sexual Bimaturism is an evolutionary idea that affects both sexes and how they develop. In humans, Sexual Bimaturism is evident in how males hit puberty about two years later than girls. This is because in nature polygyny, a marriage system that humans probably practiced in which many females were under one alpha male, has selected for late maturing males. If a young male were to hit puberty early and compete for females he most likely would have been killed by the bigger, stronger male who hit puberty later and "waited" before entering the sexual game.

Types of marriages and how they were to develop

Polygyny - Many females under one male - The typical Bimaturism that tends to develop from this is a slow development on the male part and fast, or normal, development for the female. Example, Humans Polyandry- Many males under one females - The typical result is usually a slow maturing female while a fast or normally maturing male. Example, Hyenas

This is not to be confused with Sexual Dimorphism in which Sexual Selection directly effects natural selection and selects for males with "desirable" traits for females, who almost always selects the mate.

References

Pratt, Nancy C., and John A. Phillips. "Functional versus physiological puberty: An analysis of sexual bimaturism in the green iguana.." Animal Behaviour 47.5 (1994): 1101. Academic Search Premier. EBSCO. Web. 15 Sept. 2011.