Sexual Conflict in Humans its Effect on Reproductive Success

The study of sexual conflict arising from the differing reproductive interests of males and females in the sexually-reproducing species (Chapman, et. al. 2003: 41) such as human beings have, for a long time, been a very interesting undertaking for many scholars. This is due to the enigma surrounding the co-evolution of the male and female—wherein the former is likely to develop an entirely different reproductive physiological characteristic from the latter—which has left many scholars and scientists bewildered as to the benefits that sexual conflict has for the female human species.(Bestor, 2003; Chapman et. al. 2003; Stoddart, 1986 ) Thus, the exact reasons for the occurrence of sexual conflict among humans has yet to be proven but it is widely believed to be a part of the evolutionary mechanisms of the homo sapiens to adjust to environmental, biological, and cultural factors.

Environmental, Cultural, and Biological Factors of Sexual Conflict

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!

order now

As a sexual species, humans arguably suffer from the disadvantages of sexual reproduction. Bestor (2003) points out that “the short-term disadvantages of sex are severe,” including the presence of threat of impotence, the time and resource consumed in getting and maintaining a partner, the risks of sexually-transmitted diseases, and the fact that “obligate meiosis prevents the transmission of genotypes of exceptional fitness to offspring, and as a result exceptionally fit females tend to bear offspring of lesser fitness.” (Bestor, 2003: 185) These factors undoubtedly make women more discerning in their mating choices, which contribute to the development of reproductive strategies that allows them to choose their partners for fitness and genetic viability and also cultural considerations that involve expectations on the quality of paternal care, access to resources, and absence of diseases. (Chapman, et. al., 2003: 41)

However, the primacy of the female preference produced competition among the males in the conquest of female partners  and would also lead to the development of characteristics that would make the male more attractive to the females. To counter these, the females evolved their own set of defenses and resistance, and as the male and female species co-evolved, it would result in the “an array of behavioural, morphological and physiological sex-limited adaptations that confer benefits on each sex against antagonistic adaptations in the other,” (Parker & Partridge, 1998: 262) or the development of sexual conflict, defined as the “differences in the evolutionary interests between males and females’ that can occur between the same or different genes, that is when there are different optima for a trait expressed in both sexes intralocus conflict) or when there is conflict over the outcome of a male–female interaction.” (Chapman, et. al. 2003:185)

For instance, Chapman, et. al (2003) reports that human beings, through natural selection, have actually developed sexually antagonistic genes in their sex chromosomes that are responsible for the differences in the physiological and morphological traits of men and women (e.g. wider hips of the female for child-bearing) to adapt to their reproductive roles. In the same manner, among the most studied characteristic in the human reproductive behavior is the absence of ovulation signals or oestrus among the females which is in stark contrast with those of other animals. The repression of ovulation signs, normally exhibited by other females in the animal species, is shared by other primates and is considered a strategy by which females are able to escape from the sexual aggression of other males when their partner is not around, a necessary strategy to ensure the offspring’s paternity (and to prevent genocide by the male), male provision of food and other resources, and “avoidance of direct mating costs.” (Pawlowski, 1999:258; Chapman et. al., 2003:42; Stoddart, 1986)

Sexual Conflict and Reproductive Success

Sexual conflict therefore ensures the continued evolution of the human species to increase its fitness in reproduction and to screen for genetic quality and fit. For the males, sexual conflict forces them to develop behaviors and genes that favor male parental care and characteristics that would make them more desirable to the opposite sex. For women, it allows them to avoid the manipulative behaviors of the male and also enables them to screen for partner fitness. Sexual conflict also plays a role in speciation, as demonstrated by Parker & Partridge (1998) through its influence in genetic mutation.

Unfortunately, sexual conflict may also have disadvantageous effects for the reproductive success of humans. Parker & Partridge (1998) note that the long-term consequences of sexual conflict may cause the rapid, independent evolution of the male and female reproductive traits into divergent paths that favor limited sexual activity. (Parker & Partridge, 1998: 262) Male sexual aggression, for instance, may develop in women an avoidance behavior to preserve herself, and scholars have pointed out that the possibility of an “arms race” between the males and females which could result in unhampered evolution of differing sexual strategies. Likewise, it seems that the burden of reproductive costs, as a result of sexual differentiation arising from sexual conflict have been carried more by the female than their male counterparts, especially in the care and provisioning of the offspring and in the physiological damage that sex brings to mature females. The tendency for the females is therefore to avoid “male-imposed costs rather than the acquisition of benefits from preferred males.” (Chapman et. al. 2003: 42)

Thus, while sexual conflict in itself is a result of the adaptive behaviors of the male and female, it may be one that has both advantages and serious side effects for human reproductive success.