Pas de Deux of Sexuality Is Written in the Genes – New York Times

Current Affairs / Science

News from ongoing research into human mating and orientation studies:

“When it comes to the matter of desire, evolution leaves little to chance. Human sexual behavior is not a free-form performance, biologists are finding, but is guided at every turn by genetic programs.

Desire between the sexes is not a matter of choice. Straight men, it seems, have neural circuits that prompt them to seek out women; gay men have those prompting them to seek other men. Women’s brains may be organized to select men who seem likely to provide for them and their children. The deal is sealed with other neural programs that induce a burst of romantic love, followed by long-term attachment.

So much fuss, so intricate a dance, all to achieve success on the simple scale that is all evolution cares about, that of raisingthe greatest number of children to adulthood. Desire may seem the core of human sexual behavior, but it is just the central act in a long drama whose script is written quite substantially in the genes.”

Some of these results are news to me, many of them I’ve read before. I’m particularly interested by the discussion about the possible evolutionary strategies which could explain why if same gender orientation is genetic it is being passed on by heterosexual parents.

Read the rest here: Pas de Deux of Sexuality Is Written in the Genes – New York Times

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9 Comments

  1. ruidh says

    There are a number of reproductive strategies which depend on near relatives assisting with the raising of offspring. If a near relative is not raising his own children, he could be helping raise a niece or nephew. That child could be carrying a recessive trait that could reexpress itself in a future generation.
    There are probably other things going on as well. There’s a lot we don’t know about how trace molecules in the environment can influence pre-natal development. It’s quite possible that a pathway leading to a homosexual orientation is turned off until some environmental cue indicating dense population switches it on. Thus the trait gets passed on until it is needed.

  2. I’d like to hear, though, how “to achieve success on the simple scale that is all evolution cares about, that of raising the greatest number of children to adulthood” applies on an individual level to, say, bees – or human beings.
    There is only one reproducer in a colony of bees; all the workers are females and are apparently not wired to reproduce their own individual genes. They exist for another reason: a social one.
    It’s not even very hard to come up with similar examples in human society; there was a book out not long ago called, I think, “How the Irish Saved Civilization.” And that happened, guess where? In the monasteries. I had this conversation not long ago on another blog; I think we’d all agree that the Catholic Church – and its monastics and celibate priests since the Middle Ages – was absolutely central to the formation of Western Civilization.
    So while it may be true that “raising the greatest number of children to adulthood” is the prime mover of evolution, it’s nevertheless true that human beings are, as everybody is implying here, extremely complicated and very, very social as creatures. IOW, we’re not talking about individuals here – and probably not even about “raising children” directly – but about society and the social function.

  3. Ruidh and bls – exactly. The point is that the evolutionary strategies used by different species are a bit more complicated than simply having the most children possible. If that were the case, the world would be ruled by species like insects and fish that have hundreds and thousands of offspring each time they reproduce.
    Human reproduction is actually fraught with danger because of the size of our brain pans – and the way that size has to limited so that the newborn child can safely pass through the birth canal. The size of our brains would seem to be a mal-adaptive response to the simple understanding of evolution which works to provide the largest number of surviving offspring… Except that there are obvious advantages to having a large brain, as our species domination testifies.
    I guess I’m responding to the standard criticism that I’ve heard of the argument that any genetic aspect to sexual orientation. People keep saying that if orientation is genetic, it should quickly breed out of the species because of the lack of offspring…

  4. A MacArthur says

    I just posted a comment on Daily Episcopalian addressing this very topic of evolutionary advantage.
    I believe the evolutionary advantage may have been conferred when the division of labor into male hunter, and female gatherer and early child rearer occurred. The males in the early societal groups would have been gone on lengthy hunting expeditions. It would have been advantageous for those groups to have a male attracted to the same sex. He would have provided succor, sexual and other, i.e. tending camp, cooking etc. to the other members of the group,thus leading to a smoother operation, and a more successful hunt. Those groups lacking males with same sex attraction would be at a selective disadvantage.
    I indicated in the other post that the hypothesis was untestable, not unlike many other hypotheses for selective advantages, but on second thought, perhaps cultural anthropological studies of hunter gatherer groups isolated from the influence of agrarian or industrial societies, might shed light on this.

  5. Ummmm.. I can cook and clean and change a tire and put a bookshelf together, and I’m a right good shot with a rifle. Being a gay male just like being a woman is more complex than that we cook and clean while the “real” men do the hunting.
    I’m frankly highly leery of “usefulness” arguments when thinking about gay folk because of a longstanding tendency to do this with minorities in a way that makes us completely utilitarian to the majority and therefore expendable when not of use. Christian ethics do not allow us to consider others in terms of mere usefulness to ourselves or society; we who are gay have our own telos within the human family, and its not simply to be useful to heterosexuals, but also joy according to our condition and vocations of various sorts.
    My partner’s home village is 25km from Bergen-Belsen. We visited one cold winter, walking past the graves with markers reading “5000 buried here” and “10000 buried here” all across the countryside. Most of those who died at Bergen-Belsen were homosexual men worked to death–quite useful to the National Socialist state who otherwise thought of homosexuals, who were among the first rounded up, as “those not fit to live”. Reminds me of Auschwitz: “Arbeit Macht Frei”, work makes you free.
    Dr. Crew wrote this and I largely agree with him:
    I must confess that I am not impressed by the genetic studies of
    homosexuality.
    Can you tell who’s disposed to be a Christian by sweat samples or by the
    ratio of the length of the middle toe to the length of the middle finger?
    And what on earth would you want to do with the information? Stop
    Christianity in utero?
    The genetic research about homosexuals appears to be appropriately neutral,
    but the heterosexual majority has manifested a steady tendency to use any of
    the ‘findings’ to justify discrimination against lgbts.
    Nazis measured absolutely everything about Jews before baking them.
    Many genetic studies presume ‘a homosexual’ as a fixed identity. Even those
    of us who self-identify publicly are at different places on Kinsey’s scale.
    Must one be at least a Kinsey 4 to qualify?
    Just how many drops of African blood does it take to be black?
    Kids in my jr. high school in Alabama were certain they too could spot
    queers, and if spotted, abuse us; so we queers learned not to wear green on
    Thursday, not to look at our fingernails with the fingers held out
    straight,…… Some found the best camouflage was to be a queer basher
    too, as many still do in ‘conservative’ Christianity.

  6. Christian ethics do not allow us to consider others in terms of mere usefulness to ourselves or society; we who are gay have our own telos within the human family, and its not simply to be useful to heterosexuals, but also joy according to our condition and vocations of various sorts.
    *Christopher’s comment is the best one of all, I think.
    Remember that the first individual convert to Christianity was the Ethiopian Eunuch; remember that Christ preached that all who did God’s will were His family.

  7. A MacArthur says

    In reference to my previous post, I was proposing an evolutionary hypothesis, not an ethical argument. I don’t believe any group’s existence should be justified simply on the basis of how useful they are. Nor did I mean to imply that the individuals that were gay would not be taking part in the hunt.
    I don’t know why people would be more inclined to discriminate against gays if a genetic basis for same sex attraction were found.

  8. Why? The recent Al Mohler would then have reason for in-utero removal of anything gay. And I doubt he’d be the only one to go in for a fix. Fact is, the heterosexual majority doesn’t have a good record in this area. Evolutionary hypotheses have ethical implications as the past century on race and evolution show, and so I’m going to put them to question again because the majority doesn’t have a good record once the hypothesis moves out into how we’re treated.

  9. ALM says

    What you are proposing is that it is better to remain ignorant in any area of science which would result in negative ethical consequences.
    I can think of many discoveries that should not have been made if we consider the consequences, for example:
    1)flint making to produce sharp objects
    2)taming fire
    3)discovery of poisons
    4)discovery of explosives
    5)symbolic objects to stand for material objects, i.e., money
    and so on,up to the discovery of the nature of the atom (and beyond!)
    The whole Pandora’s Box!

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