Rereading last week’s post on the role of biology in one’s LGBT status, I found myself still a bit confused.(1) I wanted to understand more about the role of genetics, or as some people refer to it, the “gay gene.”
It did not go well. Reading Wikipedia’s entry on Biology and Sexual Orientation, I felt like my brain was simultaneously shutting down and bursting into tiny flames. A feeling I had through pretty much every minute of high school Algebra 2, it made me angry. As a smart person, I should be able to understand this stuff -- so I tried again.
“In 1993 Dean Hamer and colleagues published findings from a linkage analysis…”(2)
Zzzztttt...
“Gay brothers who showed this maternal pedigree were then tested for X chromosome linkage, using twenty-two markers…”(2)
ZZZZTTTT!
“In another finding, thirty-three of the forty sibling pairs tested were found to have similar alleles in the distal region of Xq28…”(2)
POOF!
“This was popularly dubbed the ‘gay gene’ in the media…”(2)
Aaahhh…Finally something that makes sense. And then my brain really shut down. Because anytime I read something has been “dubbed by the media” I immediately worry that there’s no such thing. Any entity that can invent such things as the “War on Christmas” and “Brangelina” is not to be entirely trusted.
First one thing, as I mentioned last time, whatever role genetics play in one’s LGBT status it is not simple or complete. “A (Northwestern University) study found that, while gay men shared similar genetic make-up, it only accounted for 40 per cent of the chance of a man being homosexual.”(3)
Forty percent: That’s not much. Certainly not enough to label something an entirely “gay gene.”
Having said this, America is also a country where cars can contain only 40 percent American parts and still be made in the USA.(4) Where baseball players can hit the ball only 40 percent of the time and be considered the best ever. And where an Adam Sandler movie like “Big Daddy” can be liked by only 40 percent of reviewers and still make nearly a quarter-of-a-billion dollars.(5)
Clearly, 40 percent is good enough for a lot of people.
I am not a lot of people, however, and I’m normally loathe to just go with the crowd. (Not enough ostrich feathers in their wardrobes for my taste.) The fact is, though, this “gay gene” is what many people are talking about. So it makes sense to understand it, thus my repeated attempts to dive into Wikipedia.
One thing I did understand from Wikipedia was the name of the gene in question: Xq28. (No, the “q” does not mean queer; that’s not how genes are named.(6) Though that would be pretty cool.) And in one of those delightful moments that justifies my faith in research, less than three weeks ago -- February 2014 -- new evidence of Xq28’s importance was released. The highlights are as follows:(7)
* The X chromosome known as Xq28 has some impact on sexual orientation
* Another stretch of DNA on chromosome 8 also affects male sexual behavior
* The findings confirm the results of a 1993 study that found that more than 10 percent of brothers of gay men were gay themselves. (This is a vast difference from just 3 percent for the general population.) This is possible only as a result of genetics.
The reason this last part is so exciting is because two studies, more than 20 years apart, run by two different institutions, appear to show the same thing.
(Again, though, the Xq28 gene is only responsible for about 30 to 40 percent of male homosexuality, “while environmental factors, including the hormones a fetus is exposed to in the womb, may also influence a man’s sexuality.”(7))
I also found it interesting that the gene in question is one passed along by the mother. Why, from a biological standpoint, would a female pass along a gene that makes it LESS likely that someone will biologically reproduce?
If your goal is continuation of the species, you have to admit it’s a terrible idea. It would be like Adam Sandler telling people they shouldn’t go see his movies. (Which, in the case of “The Waterboy,” is still the only right thing to do.)
Scientists aren’t sure why this is, though they have theories. “Researchers have speculated in the past that genes linked to homosexuality in men may have survived evolution because they happened to make women who carried them more fertile. This may be the case for genes in the Xq28 region.”(8)
Another thing they’re not sure of: Why do females become gay? The studies cited above were on men. “Interestingly no similar genes have been discovered which influence female homosexuality.”(3)
This doesn’t mean there’s not a genetic aspect to being a gay woman. According to a 2011 study in The United Kingdom on identical twin sisters, “Lesbianism is indeed at least 25 percent genetic.”(9)
Still, according to the same study, “no one has yet produced a viable explanation for how the genes that promote lesbianism might” move from one generation to the next.(9)
One thing they do know, however: like men, a female's sexual orientation also appears to be partly influenced what she’s exposed to in the womb. In a woman’s case, the male sex hormone androgen.(9)
“Greater hormone exposure correlates with more gender nonconformity early in her life (as a child, she may be called a "tomboy"), as well as a same-sex orientation later on.”(9)
Certainty, uncertainty: There seems to be a lot of both in terms of scientists’ understanding of what makes people LGBT. Indeed, some people use this to discredit all research, choosing to cherry pick from those things scientists don’t know to discard all those we do.
That’s politics, however, not science. Indeed, just this year scientists were revising their theory of how gravity works.(10) Does that mean gravity doesn’t work? Are things going to suddenly start not falling from the sky because there’s an aspect of the science we don’t understand? Certainly not, with all due respect to Wile E. Coyote.
It just means that our understanding is incomplete, not invalid. A mystery that needs to be solved. Kind of like Adam Sandler movies.
References:
1) RainaBowe.Weebly.com: Nature, nurture: Let’s call the whole thing fairly
www.rainabowe.weebly XXXXXXXX
2) Wikipedia: Biology and Sexual Orientation
https://en.wikipedia.org/wiki/Biology_and_sexual_orientation
3) The Telegraph: Being homosexual is only partly due to gay gene, research finds
http://www.telegraph.co.uk/science/science-news/10637532/Being-homosexual-is-only-partly-due-to-gay-gene-research-finds.html
4) Green Car Reports: U.S.-Made 2013 Nissan Leaf Has Only 15 Percent Local Content; Here's Why
http://www.greencarreports.com/news/1087122_u-s--made-2013-nissan-leaf-has-only-15-percent-local-content-heres-why
5) Rotten Tomatoes: Big Daddy
http://www.rottentomatoes.com/m/big_daddy/
5a) I’m more of a “Wedding SInger” girl, myself.
6) If you’re curious where genes do get their name, read this:
Wikipedia: Gene nomenclature
http://en.wikipedia.org/wiki/Gene_nomenclature
I must warn you, however, there is a high level of “ZZZZTTTT!” and “POOF” producing content.
7) International Business Times: Does A ‘Gay Gene’ Exist? New Study Says ‘Xq28’ May Influence Male Sexual Orientation
http://www.ibtimes.com/does-gay-gene-exist-new-study-says-xq28-may-influence-male-sexual-orientation-1555564
8) The Edge: New Study Finds That Your Mother Made You Gay
http://www.edgeonthenet.com/?155435
9) Huffington Post: Lesbianism & Genetics: Female Sexual Orientation Partly Hereditary, But Erotic 'Plasticity' Still Unexplained
http://www.huffingtonpost.com/2012/06/14/lesbianism-genetics-gay-women-sexuality_n_1597148.html
10) The Daily Galaxy: Hyper-dense Pulsar May Nix Einstein's Theory of Gravity --New NRAO Discovery
http://www.dailygalaxy.com/my_weblog/2014/01/-hyper-dense-pulsar-may-nix-einsteins-theory-of-gravity.html
“By doing very high-precision timing of the pulses coming from the pulsar, we can test, (and) finding a deviation… would indicate a breakdown of General Relativity and would point us toward a new, revised theory of gravity.”
Or, to put it another way: “ZZZZTTTT! POOF!”