A study called ‘Homosexuality as a Consequence of Epigenetically Canalized Sexual Development‘ was recently published in the Quarterly Review of Biology that proposed a model for the development of homosexuality within the womb. Here’s also a layman introduction to epigenetics.
Citing a pop-media review of the study:
First, evidence shows that homosexuality can run in families. Still, only 20 percent of identical twins are both gay, said Rice. Furthermore, linkage studies looking for a genetic underpinning to sexual orientation have not turned up any “major” homosexual genes, Rice noted. “This made us suspicious that something besides genes produces heritability that isn’t genetic.” Epigenetics fits the bill.
Most epigenetic modifications are erased during development of germ cells and soon after fertilization so that cell lineages can be programmed with new epigenetic modifications. But if epi-marks that direct sexual development are not erased correctly, a mother could pass down epi-marks that direct female development to her son, resulting in an attraction to men, and vice versa for a father and his daughters, the researchers theorize.
Rice proposes that because homosexuality can run in families, surveying the epigenomes of sperm from men with or without lesbian daughters could reveal key differences.
Fascinating as it may be to understand the biological basis of sexual orientation, however, not everyone is convinced it’s a necessary line of investigation. “Should we test this? Is it important for us to know?” asked McCarthy. “Homosexuality is not a disease, it’s part of natural human variation. I’m not sure there’s a good reason to delve this deeply into it. I think we’ve reached the point that we have enough evidence that there’s a biological basis for sexual orientation.” It would be more helpful to people to get a better handle on the epigenetics of cancer or mental illness, she added.
– http://www.the-scientist.com/?articles.view/articleNo/33773/title/Can-Epigenetics-Explain-Homosexuality-/
I often hear anti-gay people refusing to accept homosexuality as natural/born-this-way because they’ve seen people convert to celibacy or even heterosexuality. But they have no qualms with accepting heterosexuality as natural even though many heterosexuals have also converted to celibacy or homosexuality or bisexuality.
This double standard is a kind of inability to empathize – heterosexuality is natural cause I was born this way, but homosexuality is probably a result of childhood abuse or mental illness because I cannot imagine myself being homosexual from birth.
It’s also very common to hear people ask for hard proof that homosexuality is genetic. But they don’t understand that scientists are more interested in investigating other important things that need a cure – cancer, HIV, influenza, TB to name a few. Research isn’t like religion or magic – it doesn’t just appear out of thin air overnight. Researchers need money and years to perform a solid study, get reviewed by other scientists, before they publish their results in a peer-reviewed journal. And even then, knowledge is constantly improved over time by new evidence – that’s the beauty of science. Something that was “confirmed” or “proven” years ago may no longer stand up to scientific scrutiny – this is how we learnt that evolution happens, the Earth is round and orbits the Sun, and the Earth is definitely not just 6000-10000 years old.
Petitions to the government to divert research money into studies on homosexuality fall on deaf ears because, like Margaret McCarthy, a neuroscientist at the University of Maryland says, that money is better invested in finding a cure for real diseases and afflictions. If one would like to take the stand of asking the government to take cancer money and invest it in homosexual studies, I would like to invite that one to the nearest hospital to see how many cancer patients are waiting for a cure and tell those patients that we should take their medicine money and spend it on LGBT investigations.
Actually, most religious organizations collect weekly monetary contributions. If the church decides to donate that money to the government for scientific research to check for epigenetic determination of homosexuality, that would help us resolve this issue. (As opposed to spending that money on their pastor wives’ musical careers and their finance managers’ online fashion businesses…) But even the church realizes that that money is better spent on charitable organizations and education.
If you really want to know whether homosexuality is born-this-way, I think the simplest way to find out is to talk to more homosexual people and hear what they have to say. Why would anyone choose to be gay instead of straight, and to be discriminated against? It’s like choosing to be a woman in Taliban town or a Jew in Nazi Germany. I think most people would prioritize their basic human rights and freedoms above their ‘choice’ of sexual orientation. Converted homosexuals choose to walk away from their sexual orientation, but they did not choose to be born homosexual.