Although many of us believe that sexuality is culturally and biologically important, few of us know about the origins of sexuality or understand sex from an evolutionary perspective. For example, not many people can explain the evolutionary factors for human reproduction requiring two partners instead of one and why partners that can reproduce are more valued than partners who cannot. Also, few can state the biological causes of humans engaging in non-reproductive and recreational sex unlike many other living organisms.
Major Theories
In order to begin to answer these questions it is important to examine the two leading hypotheses about sexual evolution. According to Matt Ridley in “The Advantage of Sex”, the deleterious mutation hypothesis, also known as the Kondrashov hypothesis, suggests that “sex exists to purge a species of damaging genetic mutations” by recombining mutation genotypes and creating individuals with fewer deleterious mutations. Those with fewer mutations have an advantage in mate selection and eventually those with more mutations die out (1-2) In contrast, the Red Queen suggests that sex is needed to fight diseases because it “enables host species to evolve new genetic defenses against parasites that attempt to live off of them” (3). While these theories may not provide insight into romance and sexual desire, they do help to illuminate why sexual reproduction is important to us as a species.Watch this video (the first part of a PBS series on the evolution of sex) to gain a better understanding of these theories:
Human Nature and Human Sexuality
In order to get a better grasp on the definition of sexuality, it is important to understand the evolution of human nature as, with the emergence of evolutionary science, many scientists have theorized on the subject. Darwin’s theory of natural selection argued that living organisms evolved from one or a few simple forms of life through the processes of natural selection, which related directly to their reproductive success. If an organism was deemed to be more fit (meaning it had an advantage that others in the population did not) there was a high probability that the organism would survive and reproduce more frequently than those with the disadvantage. This advantage would then be passed on to the organism’s offspring. As Donald Symons states in his book The Evolution of Human Sexuality, “Natural selection is not necessarily for complexity or simplicity, altruism or selfishness, pugnacity or timidity, cooperation or conflict…it is simply for reproductive success (page 3).” While evolutionists have attempted to apply this to the idea of reproduction among humans, the advancement of modern technology (birth control) and sex services (prostitution & recreational sex) have changed and complicated the situation. Though evolutionary approaches to reproduction may be accurate in some situations, it is not necessarily the case when looking at the evolution of human sexuality and the differences between men and women in relation to sexual behaviors, as factors such as “culture” and “society” are thrown into the discussion. Also, with the movement away from sex as a means of reproduction towards sex as a recreational activity, the subject is further distorted.
Many anthropologists have attempted to further the research on this subject in depth, though they have been met with numerous difficulties. Some of the struggles associated with data on sexuality research include: 1) Human beings almost always seek whatever privacy is available when engaging in sexual behavior. Because of this human need to perform such acts only in private, it has made observation and study difficult to carry out. 2) Sexual data most likely is distorted due to fear of disclosure and desire to present the subjected group favorably. Sex is a private matter in most western societies and as such follow very particular standards and rules when being considered in conventional terms. This, therefore, provides a barrier in research as in most cases, subjects are unwilling to provide information that might paint themselves in a bad light or might deviate from said traditional norms. This causes the data to be falsified by the very subjects who are being studied. 3) Cultural relativism.
Mate Selection
One of the topics that we would like to focus on is the evolution of mate selection. The article, “Interaction Between Natural and Sexual Selection During the Evolution of Mate Recognition” by Mark W. Blows, discusses how natural selection combined with sexual selection affect mate selection. In particular, this article focuses on how the environment—natural selection—causes certain individuals to have more opportunities to reproduce. In this way then, the environment plays a large role in how mates are chosen—in other words an individual can only choose another individual to mate with if they survive long enough to mate and reproduce. According to the article, “The Evolution of Female Mate Choice by Sexual Conflict,” by Sergey Gavilets, Goran Arnqvist and Urban Friberg, sexual selection also plays a large role in mate selection. This article argues that sexual selection can be said to derive from females desire to reduce the direct costs of mating. It also says that it has been argued that female mate choice is due to genetic benefits—or that females have evolved to choose males whose genes allow them to benefit the most from their surrounding resources. In our upcoming blogs we hope to do further research on these ideas and expound upon how mate selection has evolved over the years and why.
Modern Implications
The reasoning behind mate selection in contemporary society however, is not only the genetic benefits it brings to human kind. The evolution of ‘recreational sex’ or non-reproductive sex is yet another aspect of human sexuality which may be studied at great depth.
Sex that does not produce offspring may be seen as an inefficient expenditure of one’s energy according to scientists and yet it is very much a part of human sexuality as we see it today. While humans tend to think of recreational sex or sex removed from the purpose of reproduction as a luxury, as behaviour borne out of choice and not biological prompting, Jared Diamond argues that “Behaviour evolves through natural selection, just as anatomy does. Hence if sex is enjoyable, natural selection must have been responsible for that outcome” (Diamond, 66). One reason proposed is the need to have two parents to raise a human child as unlike other mammals, human offspring take longer to develop to the stage where they can fend for themselves. Therefore, to keep the couple together (more importantly, to keep the man from impregnating another women), our biology enables us to practice recreational sex so the man will not stray looking for sexual satisfaction now that he has ensured his genes will survive. This theory however is much disputed. Other more dominant theories include the ‘Daddy-At-Home” Theory which explains that concealed evolution promotes monogamy by ensuring the man must stay at home and ensure that his wife is fertilized, whenever her period of ovulation may be, by him and him only. This also reduces the chances of a man philandering as he is unlikely to know when other women are ovulating and therefore he may be wasting his genes.
Recreational sex therefore has implications on marriage, monogamy, current societal perceptions on human sexuality and the role it plays in shaping gender roles and other related phenomenon in today’s society.
Conclusion:
Human sexuality is a topic that has been commonly expressed in more public venues, but few people take a step back to ask: Why have things become the way they are? Evolution is one way to explain reasons for sexual behaviors. It can be used to explain 'recreational sex,' asexual reproduction, and mate selection. However, when gathering information on the evolution of sexuality, researchers encounter problems because people are not usually open to giving out details of their sexual life and because society and culture greatly impact the general understanding. Human sexuality is a fascinating topic and with such a vast variety of sources (everyone is a subject because everyone has to reproduce) the discussions are endless.
Human sexuality is a topic that has been commonly expressed in more public venues, but few people take a step back to ask: Why have things become the way they are? Evolution is one way to explain reasons for sexual behaviors. It can be used to explain 'recreational sex,' asexual reproduction, and mate selection. However, when gathering information on the evolution of sexuality, researchers encounter problems because people are not usually open to giving out details of their sexual life and because society and culture greatly impact the general understanding. Human sexuality is a fascinating topic and with such a vast variety of sources (everyone is a subject because everyone has to reproduce) the discussions are endless.
-Watch this video to see how recreational sex has impacted today's view's of modern day sexuality due to the invention of birth control.
Sources:
Diamond, Jared. Why Is Sex Fun: The Evolution of Human Sexuality. NY: Basic Books, 1997.
Symons, Donald. The Evolution of Human Sexuality. New York: Oxford UP, 1979. Print.
