A Bit About Genetics and Homosexuality

Disclaimer: I am LGBTQ and an atheist.

Welp, I’m gonna do my best not to make this a rant. And to be ENTIRELY OBJECTIVE.

First of all, some background. Homosexuality, as you probably know, is when a person is sexually attracted to people who are the same gender as them. Most people (like me) feel that this isn’t a problem, and it’s OK for others to love whomever they want.

However, some religious texts such as the Bible say that being gay is a sin—”man shall not sleep with man” and all that. And some conservative Christians (well, not only Christians, but you get my drift) choose to treat the Bible’s word as law when it comes to these matters.

Note: I’m not chastising anyone for their beliefs. It’s 100% okay to be a conservative Christian. Just don’t be mean to gay people or take away their rights, OK? 🙂

Anyways, back to my point.

According to many of the Christians I’ve met online, being gay is a choice.

Their argument: Being gay is a sin. God wouldn’t create a sin. Therefore God must have created everyone straight, and gay people must choose to be gay.

My argument: Sexuality is genetic, for the following reasons.

Studies show links between sexuality and a gene on the X chromosome, Xq28, which I wrote a short story about. And here’s another link, if you want.

So maybe you’re thinking, “OK, maybe studies do show it, but it still isn’t logical. What about the people who seem to switch sexualities all the time?”

Well, there is actually a sexuality called pansexual, which means that you can be attracted to someone of any gender. And there’s one called abrosexual, which means you fluctuate between different sexualities!

A lot of the time, gay people assume they’re straight when they’re younger, just because everyone else is. They could identify as heterosexual at first, then discover more about themselves and decide they’re bisexual, then finally come to the conclusion that they’re actually gay. It happens! Figuring out your sexual orientation is a long and difficult process. It can take years!

An argument I’ve seen a lot against homosexuality being genetic is this: “But gay people can’t have kids, so how would the gene be passed on?”

Ah, well, it looks like you’re forgetting what middle school science taught you about genetics! Time for a recap.

(Don’t worry; everyone does it. 😉 Sorry if I sound patronizing.)

First of all, homosexuality is very likely a mutation (as all traits are, ultimately). This means that it was originally a DNA copying “mistake”—not necessarily an asset or a defect, just a random change in the code.

Let’s take hemophilia for example. It’s a genetic disorder that makes it very hard for a person’s blood to clot. Even the slightest injury can make them bleed heavily—not a very beneficial gene, eh?

You actually have two of every gene in your body—one coming from your mother, one from your father. These genes are called alleles. Your parents also had two alleles, and it’s random to which of theirs you get. But the two alleles are not always the same. One allele is (usually) dominant, and one is recessive.

We show dominant alleles with capital letters, and recessive alleles with lowercase letters (taking hemophilia as an example):

HH – normal
Hh – normal, but carrying faulty “h” gene
hh – hemophiliac

(Important to note that the genetics of hemophilia is a little simplified here, but it gets my point across fine.)

Recessive alleles will only be present in an organism’s phenotype (observable characteristics) if there are two of them. In other words, the dominant allele “masks” the recessive one.

It’s also important to note that recessive alleles are not necessarily less common than dominant ones—it just has to do with how many copies of the gene are in the population.

As for how the gene could be passed on—through carriers! Carriers are people who have a copy of the faulty gene, but it doesn’t present itself in their phenotype. So a person could be have the gene for hemophilia, but not have hemophilia themselves.

If two carriers (Hh and Hh) had a kid, there are many ways in which their genes could be “scrambled”. We figure out the probabilities of each combination by using something called a Punnett square:

Punnett square

See that hh? There’s a 25% chance that the two carriers’ kid could have hemophilia!

This is all very fine and dandy, but how does it relate to homosexuality?

Well, I think that homosexuality may be a recessive trait. People could be carriers of homosexuality and never know it! Maybe you’re a carrier, even! And if two (unknowing) carriers have a kid, then by this logic, there’s a 25% chance that they could be gay. It’s probably a lot more complicated than what I just explained, though! But I’m not really an expert in genetics… I just happen to know a fair amount about the basics. 🙂

Well then! I hope I made you think! Comment any questions, but please be respectful.

For more information about Mendelian genetics, here’s something.

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2 thoughts on “A Bit About Genetics and Homosexuality

  1. thedreamer01 says:

    This is a great, simple, explanation! This makes me wonder if homosexuality is more common in people who are physically male, since like for sex-linked disorders, there is no other X chromosome to mask the receive trait. It would probably be difficult to tell, since so many people are in the closet, but it would be an interesting study.

    Liked by 1 person

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