The debate as to whether homosexuality is a consequence of genetics or a lifestyle choice might not go away anytime soon. But a new study might have lent credence to the belief that the so-called “gay gene” exists, as researchers believe they have found certain genetic features that could determine whether a man is gay or not.
Studies that have sought to identify genetic variations that influence homosexuality are nothing new. As explained by New Scientist, two studies in the 1990s identified regions on certain chromosomes that were linked to whether men and boys were heterosexual or homosexual, and while the findings were confirmed almost two decades later in a separate analysis of gay and straight brothers, neither paper identified a specific gene responsible for male homosexuality.
The new study published this week in the journal Scientific Reports claims to be the first of its kind to identify specific genes that could influence a boy or a man’s sexual orientation. A team of researchers led by NorthShore University psychiatrist Alan Sanders analyzed DNA from more than 2,000 men, including 1,077 who identified as gay and 1,231 who identified as straight. Sanders and his colleagues looked for single-letter differences in the men’s DNA sequences, allowing them to pinpoint two genes that have variants possibly associated with sexuality.
Based on the findings, the first gene is found on chromosome 13, and this is notable as the gene is active in the diencephalon, the region of the brain where the hypothalamus is found. According to New Scientist, the hypothalamus was previously found to be a possible determining factor for a man’s sexual orientation, as it differed in size between both straight and gay males. The second gene, on the other hand, is located on chromosome 14, and since it is active in the thyroid, it backs up previous research linking thyroid function to sexual orientation.
But that still doesn't mean there's a 'gay gene'.https://t.co/M0P8H0oJiL
— ScienceAlert (@ScienceAlert) December 7, 2017
Speaking to Newsweek, Sanders explained that his team’s study does not necessarily state that the “gay gene” definitely exists, as genetics might only contribute up to 30 percent of the factors related to homosexuality.
“We know that sexual orientation has some hereditary or genetic contributions. A common scenario in this kind of research is that you’ll hear people use a sort of shorthand like ‘the gay gene,’ which is not really accurate at all.”
Even with Sanders’ admission that “gay gene” might not be the right term to use when discussing his team’s research, Newsweek noted that there was a “raft of caveats” accompanying the study’s results. All of the men who had their genomes analyzed, whether gay or straight, were white, and no bisexual men were included in the study. The sample size was also relatively small, particularly since the 1,000-plus homosexual men were reportedly recruited at gay pride parades and other similar events.
All of the above concerns were brought up by scientists who commented on the paper via the London-based Science Media Center, Newsweek added. University of Oxford statistical geneticist Gil McVean also stressed that the results have yet to be replicated in independent research and that the evidence is “preliminary” at best. Likewise, Francis Crick Institute developmental biologist Robin Lovell-Badge said that he doubts that there is causality in the results, adding that it’s too much to say that certain genes influence a man’s sexual orientation in any way.
A disease with a potential cure. Do ‘gays’ rejoice or finally -choose- to remain gay? Either way, no more parades.https://t.co/HIBfudvZlL
— Von Sheep (@vonsheep) December 8, 2017
Critical comments on the study weren’t limited to those that came from genetics experts. In an op-ed for Uproxx, Dan Seitz wrote that there were many nuances that the researchers may have missed out on in their search for a gay gene. He pointed out that there were variables that were not taken into account in the study, such as the possibility that some of the men who took part in the research may actually be closer to bisexual and the fact that women were not tested for “lesbian genes.”
In conclusion, Seitz opined that there is no one specific gay gene and that a person’s sexuality may be influenced by more than just genetics, with social pressures and environment also playing a part in determining someone’s sexual orientation.