Homosexuality’s deep biological roots

In the court battles over Proposition 8, the underlying question was whether homosexuality was a choice or biological. Critics often say “you can’t find a single gay gene”, but humans are squishy — they are resultant of about thirty thousand genes which build and detract and modify one another like ripples in a pond. Saying there’s no single gay gene is as accurate as that there is no single hair color gene, but both have every appearance of being genetic, and geneticists are quite convinced this is the case. And honestly, so am I. Nobody would intentionally choose to grossly limit the number of people they can choose partners from, while simultaneously opening themselves to hate crimes from complete assholes.

Most geneticists consider sexual orientation a phenotype — namely, an observable set of properties that varies among individuals. Although physical phenotypes like height and weight are easier to quantify, behavioral phenotypes are intensely studied in animals and humans. Research from many directions leads to a strong conclusion: Human sexual orientation has deep biological roots.
Gay genes appear paradoxical at first blush. From the perspective of natural selection, how could they persist in the population if they lead to fewer offspring? Recent research has uncovered several plausible explanations. For example, one set of studies found that the same inherited factors that favor male homosexuality actually increase the fecundity of female maternal relatives. By balancing the number of offspring, they would contribute to maintaining these genes over the course of evolution. This explanation may not be exclusive but serves to illustrate that the Darwinian problem is not necessarily overwhelming.

The article also talks about epigenetics, which I really don’t understand outside of the dictionary definition. I should probably go toddle off to Scicurious’ place and see if she’s talked about it in her archives.

Update 29 Aug 2011: So this is one of those blog posts I keep going and linking back to, but the article I originally linked has disappeared. Sigh. Here’s an alternate report discussing a study of gay brothers’ genetics. While genes might not be the only factor, while epigenetics might still play a role, it’s fairly obvious at this point that just like there’s no single gene that controls how tall you’ll be, sexuality might be an emergent property of a number of unrelated (and advantageous for other reasons) genes coupled with some epigenetic factors.

Homosexuality’s deep biological roots

19 thoughts on “Homosexuality’s deep biological roots

  1. 1

    even if it was conclusively determined that homosexuality has biological roots, which I highly doubt, it still wouldn’t discredit the fact that it is morally wrong.

  2. 2

    Whether you doubt it or not doesn’t change its reality, Daniel. No more than how you doubt evolution or heliocentrism or rainbows being diffraction of light rather than arranged by your deity. You are welcome to your opinion, but you do NOT get your own reality.

    And how was this “fact” arrived at, that it’s morally wrong? Who is being hurt by two same-gender humans loving one another, that makes it a moral question at all? You don’t get to assert that it’s morally wrong baldly like that, without also presupposing your deity and that what’s recorded in your really-old fairy tale books is actually this deity’s will. And those are some pretty huge assumptions.

  3. 3

    Daniel bloviated:

    even if it was conclusively determined that homosexuality has biological roots, which I highly doubt, it still wouldn’t discredit the fact that it is morally wrong.

    There you go with your absolute morality again. Using phrases like “the fact that it is morally wrong” when referring to homosexuality only give credence to my opinion that you are another homophobic bigot, just like zdenny.

  4. 4

    The self-contradictory concept of a “moral fact” is so laughable I’m almost tempted to call Poe.

    “Good” and “bad” are always matters of opinion at their core, even if those opinions are basic assumptions like “pain is bad” or “a prosperous society is good” which almost everyone can agree to.

    Putting that aside, ethical choices usually boil down to choosing the lesser of two evils. The evils of homosexuality basically just amount to the hurt feelings of those who choose to be offended by homosexuality. (taking offense is ALWAYS a choice) The evils of discriminating against and demonising homosexuals however are very real, including teenage suicides, hate-crimes, destroyed families and a loss of valuable talent and diversity.

    Clearly trampling on the feelings of the prejudiced is the lesser of the two evils. Homophobia is going the same way as racism, and good riddance.

  5. 5

    Rikaishi mentioned:

    The self-contradictory concept of a “moral fact” is so laughable I’m almost tempted to call Poe.

    Daniel’s not a Poe, as far as we’ve been able to determine. He seems to emphatically believe the bigotry and hatred that he spews.

  6. 7

    Yup… seconded. Mr. Maldonado is, after all, a Real Theist. Though, that could be a case of “the lady protests too much”, I honestly can’t imagine someone slipping into a Poe role for years on end. That’s a crazy long con.

  7. 8

    Daniel…you’re what is known as a bigot. I’m gay and I’m not immoral or wrong…ask my friends !

    As for the article and the “normal” freethinking people on here..I like my phenotype..it made me what I am, what I always have been (no matter how much I tried to like the ladies and their soft parts ) and what I always will be.. I’ve dealt with what I’ve been offered….

    Now Daniel…most intelligent people know that the most bigoted people are actually scared of themselves….so how long have you had this craving for cock ? (apologies to Dan & Jason) but zdenny’s little brother got my goat !

  8. 9

    Daniel, you wouldn’t know logic if it bit you on the ass. Hypocrisy seems to be your middle name, and you still don’t have a grasp of its true meaning. You’re pathetic. You’re a bigot because you define some of your fellow human beings who share this planet with you as not eligible for the basic rights that you and others enjoy. How is that not bigoted?

    You fucking Christian bigots are all alike in that you can’t see the shit that spews out of your mouth for what it is. You make me sick, and I hope that one day, one of your children comes up to you and says, “Dad, I’m gay.” I would feel sorry for your child, having a condescending prick like you for a father, but I would sure love to see the look on your face.

    Piss off, you homophobic troll.

  9. 10

    Well, at least one person here doesn’t deny that moral values “…are matters of opinion…”, I’m glad to know that our entire legal system is “bigoted” to impose their opinions or the opinions of any large group on other groups opinions. Who are you to say that I am a bigot? Are you imposing your “opinion” or “moral value” on mine? This is so typical. What Rikaishi means to say is that “Good and evil do not exist.” If that’s the case, why in the world do you care if my moral value bothers you? One word best describes each of you, hypocrites. Your own logic destroys your position.

    Petursey, I could care less whether you are gay or not. It makes no qualitative difference in my life. You say, “I’m a moral person”, but by what standard are you specifically referring too? That statement must be attributed to an objective moral value by which you adhere too. Remember, your friend Rikaishi said moral’s don’t exist (pretty much), so it doesn’t matter whether or not your gay or I’m Christian who believes a gay lifestyle is morally wrong, so why bother calling me a bigot, it’s just an opinion. You might say, “Well, it’s wrong because it hurts other people to believe that…”, by what standard? Why is it wrong, who told you that hurting someone emotionally is an immoral thing to do?

    I have friends who have chosen this lifestyle and although I don’t hang with them too often, I’ve never been bigoted towards them, so long as they know my position on it. Now, your vulgar language is highly disrespectful, but why should you care right? I’m just a Christian. Tell me, how normal does it seem for one man to place his genitals in where another man defecates? Seem normal? No reproductive reason, just purely sexual lust. After all, there are plenty of men I love. I love my brothers, my father, my cousins, and my friends. The determining factor is lust. I don’t lust for my guy friends sexually and you may lust for your special guy friend in this way (if you have one, most homosexuals dont like committed relationships, not a surprise). Lust in this way, in the Bible, regardless if it’s for a woman or the same-sex is morally wrong. These things are far from normal, but you have free will to do them.

    “So God abandoned them to do whatever shameful things their hearts desired.” Romans 1:24

    “That is why God abandoned them to their shameful desires. Even the women turned against the natural way to have sex and instead indulged in sex with each other. 27 And the men, instead of having normal sexual relations with women, burned with lust for each other. Men did shameful things with other men, and as a result of this sin, they suffered within themselves the penalty they deserved.” Romans 1:26-27

    Paul teaches forgiveness after this, that although one has committed sin, he can be forgiven. Jesus came to save sinners. Bigoted message? By what standard?

    “The fool hath said in his heart, ‘there is no God'”

  10. 11


    I couldn’t have put it better myself !!!

    I’m not going to even dignify the bigot with a response as Dan has said everything that needs to be said.

  11. 13

    Til’ next time friends.

    I resent that remark.

    I must also point out that the apostrophe should come before the ‘t’ as it’s a contraction for the word ‘until’.

  12. 14

    “What Rikaishi means to say is that “Good and evil do not exist.”” Rikaishi disagrees.

    Please don’t make assumptions about what people “mean to say”, especially when you disagree with them because of a difference of perspective which naturally makes it difficult to follow their reasoning.

    “who told you that hurting someone emotionally is an immoral thing to do?” My parents originally. I figured out why it is immoral by myself, and I didn’t always apply the rule very well until I figured out why. Reasoning is important.

    Also, you failed to read my post properly, I was talking about real, physical harm that occurs to gays and lesbians.

    For this and other reasons I call ye troll and refuse to waste more time on this argument.

  13. 15

    Two profound statements from the world’s most prominent atheist’s. Your emotional outbursts do nothing to strengthen your case. I’m over this topic. Til’ next time friends.

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