Evolution and Human Behavior: Darwinian Perspectives on Human Nature - Essay Example

Sexual selection is an important natural phenomenon of reproduction. Reproductive success in both males and females is vital in maintaining the existence of lineages within populations and avoiding the extinction of species (Cartwright 17). Understanding the identification of traits that affect the reproductive system is necessary in order to understand the evolutionary process. However, it is worth noting that mating success does not necessarily mean reproductive success (Cartwright 17).

Factors that contribute to longevity influence reproductive success in males in comparison to trait factors. The reproductive value of males is not determined by physical appearance but reproductive investment (Ellison 14). Genetics and behavior reveal that males are aggressive and competitive though certain traits strengthen the capacity of other individuals. Behavioral traits such as boldness, assertiveness, and activeness make the dominant male more attractive to the females. A high-status male is quite preferable as a mating partner. The male guarding trait is significant in reproductive success because a male who protects his offspring has the potential of achieving reproductive success.  The age and maturity of a dominant male affect reproduction. Younger males are viewed as fit for copulation and breeding in comparison to older males.

Fertility in males is also important in reproductive success because sperm competition is linked with length. The longer the sperm tail, the faster it can swim, and the higher the chances of fertilization. Human males with longer sperms are more viable and vice versa. Human male height is quite preferable because it is associated with strength and protection by female counterparts. The male body size is significant in selecting a mate. It is a fact that women prefer men with broad chests and muscles as compared to thin short men (Cartwright 87).

Females choose their breeding mates after considering certain factors. An example is good genes because they look for males with certain phenotypes with the hope that these characteristics will pass on to their offspring. Hormone regulation and age is a major determinant of reproductive success in females. Estrogen is an important hormone in human females during breeding and pre-breeding. Its concentration is associated with reproduction success. Older women who have attained menopause are incapable of conceiving while younger women are highly prolific (Ellison 124).