Could there be Evolutionary Advantages of Homosexuality?

For Photo Credit see Sources Section

Psychology Today (2009) published and interesting article about the potential evolutionary adaptations of Homosexuality that I found very interesting. The article discuses a proposal of a continuum of masculinity and femininity. This "Tipping Point" hypothesis suggests that there are essentially 5 feminine alleles. If a man inherited all 5 alleles he would be completely feminized - meaning he would be homosexual. If, however, he inherited less than the full 5 he would have feminine traits (the more alleles, the more feminine) and consequently would be more attractive to women. These traits could include empathy, understanding, physical attractiveness, etc.
While tests on this model have not yet found any conclusive evidence the hypothesis is unique and intriguing.

In another article by Kenrick (2010) an additional observation is explained. It has been observed that homosexual individuals are notoriously more promiscuous than their heterosexual counterparts (please pardon my stereotyping, but this is looking at averages). Because homosexuality is highly heritable it could be beneficial to the relatives of an homosexual individual. In other words, the relatives of a homosexual individual likely have more sexual desires than people without homosexual relatives. This sex drive often relates to more children and the genes are then passed on (which indirectly passes down the homosexual individual's genes as well). (para 10).

This concept is not the same as the hypothesis that homosexual people invest resources in their relatives' offspring, also known as alloparenting (which was explained in both articles). This idea suggested that people of the homosexual orientation invest resources in the children of their relatives, which would help perpetuate their own genes indirectly. This hypothesis has lost credibility over time for several reasons. When it was tested, homosexual individuals were not shown to have better parenting skills than heterosexuals, which one would expect if the hypothesis were true. Additionally, common sense dictates that since the desire to mate is a mechanism of reproduction, people who would be focused on rearing others' children would not be interested in mating at all and thus would be asexual, not homosexual.

My Thoughts
Thinking about the current world population (307.007 million people live in the US alone-see sources), homosexuality seems that it could help reduce the current world population, which could be natural selection doing its own work to prevent us from making ourselves go extinct. On the other hand, the increased promiscuity that was explained above could be increasing the world's population just the same. It's hard to say if homosexual individuals really affect the population number or not. Would be an interesting area of further research I think.

Sources:

Causey, K.; & Goetz, A.. (2009, June 10). The 'Johnny Depp Effect'-An evolutionary explanation for homosexuality. Psychology Today, A Natural History of the Modern Mind. Retrieved from: http://www.psychologytoday.com/blog/natural-history-the-modern-mind/200906/the-johnny-depp-effect-evolutionary-explanation-homosexu

Kenrick, Douglas T.. (2010, June 9). Homosexuality: A queer problem. Psychology Today; Sex, Murder, and the Meaning of Life. Retrieved from: http://www.psychologytoday.com/blog/sex-murder-and-the-meaning-life/201006/homosexuality-queer-problem

Public Data for US Population. Retrieved from: http://www.google.com/publicdata/explore?ds=kf7tgg1uo9ude_&met_y=population&tdim=true&dl=en&hl=en&q=over+population

Photo Credits:

Photo Rereived from: http://mundicogito.files.wordpress.com/2011/03/gender-symbol.jpg