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The Gay Gene

ib4walrus's picture

 The Gay Gene

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“… When male unites with female for procreation the pleasure experienced is held to be due to nature, but contrary to nature when male mates with male or female with female, and that those first guilty of such enormities were impelled by their slavery to pleasure.”

                                                              —Plato, Laws VIII 841d6


      From Plato’s years (and surely much longer before his time) to our present day, any activity, behavior, etc. relating to homosexuality carries a certain taboo because it is “contrary to nature”.  Yet despite it being “unnatural”, homosexuality has persisted.  Present-day research has provided strong evidence that homosexuality might actually be genetically linked.  If this is the case, exactly how and why does this trait still exist?  According to Darwin’s theory of evolution in On the Origin of Species, because homosexuals are not able to reproduce, they cannot pass on their genes to the next generation and so, over time, the trait should be eradicated.  Sitting in my Stories of Evolution and the Evolution of Stories English course, I mused over exactly how this paradox can exist under the theory of evolution. 


      Before further discussion of the topic, I feel that a brief background of Darwin’s theory is necessary.  The theory of evolution is based around genetic variability, adaptability to undirected changes and passing on genes to viable offspring.  When uttered, the phrase “survival of the fittest” will spark in many people the idea only the superior, physically or mentally, will be able to survival in this brutal world of nature.  However, this is not the case.  Rather the most fit are individuals who are able to pass on their genes onto the next generation, to ensure that their genetic information is retained in the gene pool.  It is this specific definition of “fitness” in Darwin’s theory which makes the trait of homosexuality a paradox.  The most fit individuals claim that title because they have the genes which prove useful in their environment and allow for them to survive long enough in order to reproduce, this process being natural selection.  Taking homosexuality by its definition, “involving, related to, or characterized by a sexual propensity for one's own sex” 3, this indicates that homosexual behavior will never result in the reproduction process, thus making homosexual individuals “unfit”.  If this is the case, why then does the homosexual trait still exist?


      Research has led to possible theories of the social benefits that homosexuality brings for either their heterosexual counterparts or themselves.  One theory, the kin selection, claims that “the homosexual-to-be has either superior opportunities or superior abilities to gather resources and that this capacity is enhanced if they withdraw from the reproductive stakes” 4.  A connection (albeit slight) can be made with Darwin’s observation of sterile female ants in their respective colonies.  In Darwin’s example, the sterile female ants’ only purpose is to care for the fertile queen as she lays eggs (kin of the sterile female worker ants).  However, as they are unable to reproduce, how and why does their innate sterility get passed on?  Darwin uses natural selection in order to reason their existence, as “the sterile condition of certain members of the community, has been advantageous to the community” 1.  Since this sterile trait allows for the population to “flourish”, the viable offspring from that specific population would continue to “transmit to their fertile offspring a tendency to produce sterile members having the same modification” 1.  Relating this to homosexuality in the human context, the kin selection theory suggests that homosexual family members take care of their siblings in order to ensure that genes (very similar to their own) are passed on. 


      This explanation however, does not make the most sense to me.  If the homosexual (sterile) members of society have the same capacities as their heterosexual (fertile) complements, and they are supposedly equal to or superior in their capabilities to acquire resources, why should they not be able to pass on their genes?  Being genetically designed without the capabilities to pass on their own genes directly conflicts with the “ultimate, if unconscious, reason for existence” 4 of living beings.


      Another theory focuses not on the reproducibility of homosexual individuals but rather on the social benefits that homosexual alliances carries.  Kirkpatrick suggests that “same-sex alliances influence reproductive success” as it helps maintain households and “help offspring reach reproductive age” 5.  For instance, in Ancient Greek societies, prominent older men would teach the younger boys societal etiquette and train them in the art of military techniques and a sexual relationship usually forms between the two2. This same-sex alliance serves as an integral component in the Greek society by educating the younger generations.  However, Kirkpatrick’s theory suggests that homosexual behavior works in conjunction with heterosexual reproduction in one specific individual.  Reverting back to the Ancient Greek example, although the older men do engage in homosexual behavior, they still lead heterosexual lives with a stable family.  In this theory, the act of homosexuality does not hold much significance, while the social benefits that comes along with it does.  This indicates that homosexuality is actually a trait for survival rather than a trait for reproduction.  In this perspective, natural selection would support the survival of this homosexual gene as the trait is ultimately contributes to act of reproduction.


      How would Darwin respond to homosexuality though?  The first appearance of the potential homosexuality gene could have first appeared by some form of random genetic mutation.  However, in order for the gene to persist through generations it must bring with it some type of advantageous quality for the carrier.  Because the concept of homosexuality can never result in reproduction, the gene must relate to some type of phenotype which allows for the species to be better adapted to survive in the environment.  As most claim that it has existed with human behavior (whether recorded or not) this must also mean that its benefits are broad enough that it can be applicable to a wide variety of changes (which humans have existed through).  As for the homosexual behavior being linked to a specific gene, it does not require a very discerning eye in comparison to the slight variances in say, pigeon species, in order for one to see if one is a homosexual.  Due to the ability for empirical observations to be carried out, many cases can be taken into account in order to come to a conclusion (if that is possible), as Darwin stresses necessity of extended the range of observations.


      This paper deals with two specific explanations for homosexuality and its connection with a specific gene.  However, this is not the only story about homosexuality.  As science progresses, more and more studies are attempting to prove that it indeed is related to a gene, though others will disagree.  There are those who believe that the behavior is brought on by environmental influences such as parental control, social factors and by personal preferences.  Homosexuality has remained a controversial topic from the earliest written records to modern day society.  The complexities of its origin and its application make it difficult to come up with a story for homosexuality.  To believe that one can reach a single right answer which can fully explain homosexuality would simply “serve to acknowledge plainly our ignorance” about the possibilities of other stories of its existence.






         1Darwin, Charles, and Joseph Carroll. On the Origin of Species by Means of Natural Selections. Orchard Park, NY: Broadview Texts, 2003. Print.

         2Dynes, Wayne R., and Stephen Donalson, eds. Homosexuality in the Ancient

World. Vol. 1. New York & London: Garland, 1992. Print.

         3Homosexual, adj. and n. Second edition, 1989; online version November 2010. <>; accessed 11 February 2011. First published in A Supplement to the OED II, 1976. 

         4McKnight, Jim. Straight Science?: Homosexuality, Evolution and Adaptation. London: Routledge, 1997. 1-9. Print.

         5Muscarella F (2000) The evolution of homoerotic behavior in humans. J Homosex 40: 51–77. 

         6Plato. Plato in Twelve Volumes, Vols. 10 & 11 translated by R.G. Bury. Cambridge, MA, Harvard University Press; London, William Heinemann Ltd. 1967 & 1968.




Anne Dalke's picture

"Not the only story"

Nope, ib4walrus, as you say: not the only story, and you're not the only member of our class to raise these fascinating questions. I think you'll be very interested @ the different story written by cr88 in Reconciling Evolution with the Existence of Homosexuality. While you puzzle over the evolutionary "paradox" of homosexuality, asking why the trait of homosexuality "has not been eradicated, "since homosexuals are "unfit" for reproduction, cr88 leads with the claim that "the surprising evolutionary benefits homosexuality may confer upon a species serve as a testament to the diversity and subtlety of means through which a species can remain evolutionarily competitive," and ends with the observation that "indirect evolutionary pathways,  while apparently requiring some individuals not to reproduce, contribute to the perpetuation of a familial gene pool."

Much of your paper here is grounded on the (somewhat shaky) "foundation" of a "gay gene." Since genes code for proteins, not for behavior (and there are many levels of complexity between the former and the latter), I'm confused (for instance) by your observation that "as for the homosexual behavior being linked to a specific gene, it does not require a very discerning eye in comparison to the slight variances in say, pigeon species, in order for one to see if one is a homosexual." Can you parse that for me? 

For more work exploring this world of gayness beyond the human species, see both the NYTimes article cr88 draws from, Can Animals Be Gay? and the renovation of Darwinian competition by ecologist and transgender activist Joan Roughgarden in Evolution's Rainbow: Diversity, Gender, and Sexuality in Nature and People, which we've referenced several times in class.