Darwin Day 2015 Questions: #4 How does evolution explain homosexuality?

Darwin Day 2015 Questions: #4 How does evolution explain homosexuality?

(Music playing) Richard Dawkins: “My question is,
for things such as homosexuality, which people who argue against
evolution ceaselessly will insist, there appears to be no linear
Darwinian reason to possess this trait.” Now that’s a very common question; it’s one of the commonest questions I get asked. How can it be that homosexuality gets passed on from generation to generation. Why doesn’t it just disappear?
Why doesn’t natural selection remove it? Well, the first thing to say is that
it’s only a problem if it’s a genetically inherited thing. And you need evidence for that. And the evidence for that comes
from twin studies. If you take monozygotic twins,
identical twins, and you find, for anything –
it doesn’t have to be homosexuality, for height or weight,
or musical ability, anything you like – and you find that identical twins,
monozygotic twins, are more like each other than
non-identical twins, significantly more like each other, then that suggests that the
characteristic concerned is heritable. Heritable means that there is a
genetic component to the variance in the population with respect
to the character concerned. In the case of height, in the case of musical ability
and so on, we find that to a greater or lesser extent, there is a genetic component;
there is heritability. And in the case of homosexuality,
yes, there is, too. If you know the sexual orientation of one twin,
then you’re better able to predict the sexual orientation of the other twin,
if they are monozygotic, than if they’re dizygotic. So there is heritability, which means
we do have a Darwinian problem. We do have to ask the question, why is it that male homosexuality has
survived down the generations, given that one might think
natural selection would get rid of it. There are various things that
are being suggested. There’s, for example,
the worker bee hypothesis that males can look after their
nephews and nieces, for example, rather than look after their own children. And so, not being sexually active yourself, not being heterosexually active yourself, could not necessarily be selected against
in natural selection because of that. A related idea, which is a bit fanciful perhaps,
is that in our wild ancestors there might have been a time when
dominant males, who had harems, went off hunting, and left the women and children in charge of males that they could trust. And you could say, I suppose,
that an ostentatiously homosexual male would be trustworthy to a
dominant harem holding male. But of course many homosexual males are actually bisexual to a greater or lesser extent. So this might have produced,
this might have provided, an alternative way for males
to get access to females. As it were, pretend to be not
interested in females, not deliberately pretend,
I’m not talking about that. So that’s another hypothesis, but I’m not very keen on either of those two theories. I prefer to say something rather more nuanced, which is that when we talk about
a gene for anything, whether it’s homosexuality or anything else, we don’t necessarily mean that the gene
inevitably has that effect. A gene only has the effect that it does
in the right environment. So it could be that a gene that
has the effect of causing a male to be homosexual in the present environment, in our present technological environment,
civilized environment, would not have had that effect
in a different environment. A possible example, and this only is for example, there is absolutely no evidence for it, a possible example would be what if bottle feeding, as it were,
brings the gene out, brings out the effect of that gene? What if a breastfed boy, who has
this gene, is heterosexual but a bottle fed boy, who has
this gene, is homosexual? Well, in the days before bottles were invented that gene would not have expressed
itself as homosexuality. So now what we may be looking at is a different expression of the same gene. Now I’m not wedded to that
particular idea at all, I find it a good example to get
across the point that the effect of a gene is not
inevitably tied to it, but depends upon the environment in which the individual is brought up. (Music playing)

99 thoughts on “Darwin Day 2015 Questions: #4 How does evolution explain homosexuality?”

  1. The evidence is in the human DNA,
    it doesn't show a person has a homosexual tendency.
    There is no such thing as a person is born homosexual.
    Sex comes from the mind… it begins and ends in the mind.
    One must have a distorted sexual attraction to be homosexual.
    The opinion you explain is bull shit.
    The homosexual act brings on sickness causing death.
    The DNA hasn't got this gene in it, to cause death.
    The act is evil… it starts with adults having sex with minors… adult with a child. The adults in all cases have already been sexually abused as children themselves .. it's called force.
    Through persistent sexual acts performed on the minor, the child gets slowly brainwashed to believe this is normal. They become homosexual adults.
    This is not a natural act. The way the sexual act is performed and the way the body is has been created to perform … does not meet the natural criteria… in men it's dirty… unhygienic…and brings on disease, eventually death.

  2. The DNA shows its nothing to do with genes. DNA is the master key.
    Dawkins has become very rich by debating and videos, authoring books, to push his opinion….the people behind him, have him push the ' lie ' ….he likes the easy life.

  3. Nice to see dawkins actually doing something worthwhile with his time rather than bashing his head against a wall arguing with religious people.

  4. It doesn't matter if it's a heritable genetic trait. So is schizophrenia and psychopathy. It doesn't matter if animals have homosexual sex; They also rape and murder for fun. Something being natural doesn't mean that something is conducive to a functioning society. Literally the purpose of society is a compromise of natural behavior. Why are we going to such great lengths to normalize such atypical behavior? The percentage of people that anonymously identify as homosexual is increasing rapidly in only 80 years. Has it been proven a constant? Sounds like the literature is basically just copping to it being environmental.

  5. I didn't know he was or looked that old. How come they have to explain everything with the evilution theory, well they make a life out of it

  6. I dislike the last hypothesis because it doesn't explain homosexuality in other species, where the environment has not changed to any significant amount.

  7. How does evolution explain the fact that only a tiny percentage of gay people are visible or ‘out’ and 99% of gay people are within the straight community and married with children?

  8. I think a test would be a great idea if one could be developed. All straight men should have to go for this, and if they are too scared to have a test then we know they are likely gay. But we could then label 100% of gay men, rather than as it is at the moment with only 1 in a hundred gay men saying they are gay and the other 99 calling themselves straight. Imagine the chaos this would cause!

  9. What proportion of the variance explaining homosexuality in the population is accounted for by the heritability factor?

  10. Survival of the fittest as been stopped because of our compassion for the weak. We save those that would have typically died in older times. Our compassion for the disabled etc is what makes us human. Does Dawkins have a t shirt "it works bitches"?

  11. Alex Jones said something in the water is making frogs gay Richard Dawkins says baby bottles are making dudes gay. I think these guys went to school together.

  12. Surely the simple answer is that for much of human history homosexuality has been deemed socially unnacceptable to one degree or another. Living in a heteronormative world you would as a homosexual be likely to follow the conventions of society and marry and have children. Thus if there is a genetic component to homosexuality it would not have bred itself out of existence.

  13. A more likely example is the richness of the diet of the pregnant mother. A society that is well-off firstly has a more varied diet, and secondly is at risk of overpopulation. I think this could trigger the gay gene, thus decelerating population growth

  14. This is a PC way of stating that being gay is caused by the environment. I guarantee you that if you raise 100 kids surrounded by gay propaganda, you will get a lot more kids growing up thinking they are gay than if you raised them without any influence.

  15. A possible explanation would be, when we already have a male or female with a strong drive to reproduce, which is not fulfilled it creates a potentially dangerous person (testosterone build up + frustration = sexual deviancy) in tribe with high amount of males or females only, evolutionary adaptation in order to not to disrupt the whole tribe is to learn to release this sexual tension with the same gender if the opposite one is not available…

  16. Seems a poor approach to me, a little bit disappointed. The sexual drive in a lot of males, no only humans, is so strong they would fck anything. Bisexuality was common in ancient Greece and Rome, so the cultural factors are important as genetics. Also in a prison a lot of heterosexual become bisexual for "necessity". That means homosexuality its between everybody's brain, like a some sort of sexual and psychological release. Genes expresses try to balance sexual drive but normally males have problems to control that, violation its common in human race, for example, but you can see dogs sodomizing like a normal thing,. The sexual drive its strong and its expressed in different ways, a lot of them not intended by the genes, like masturbation, but serves to release and control brain sexual impulses…

  17. To smart people who love science and see this: As you can see, nobody including Dawkins knows the answer.Because there doesn't have to be one.Evolution doesn't have to make sense all the time, sometimes what happens is just a coincidence.Lamarck made the mistake of trying to explain everything for example, it didn't work.

    To others: You may continue criticise Dawkins and science for not knowing some things.Because you as an ignorant person, won't accept a reasonable explanation either anyways.

  18. If that be the case why are they're usually one homosexual sibling rather than all the siblings being homosexual.

    Evolution is a "Theory" as there is no evidence in the fossil records or any other evidence.

  19. don't believe him. He says The Great Flying Spaghetti Monster doesn't exist. How dare you?? Great FSM will burn you in bitter sauce hell.

  20. I find this answer rather unsatisfying. Is it ever been studied how the "gay gene" passes from generation to generation in other species please?

  21. Interesting. See Richard Dawkins love letters. He revellers in them. I watch them all the time. So funny.

  22. 1-Nature is not designed by an engineer, certain things can seem abnormal but have no effect on the general fitness of the population, such as nipples. There are deaf people out there, they still manage to survive.

    2-Homosexuality is not genetic. Heterosexuality and homosexuality do not exist. Everyone is essentially pansexual. Social and psychological pressures define sexuality. You can look into history and different cultures. In ancient Greek men were supposed to be active partners in sex (aka tops), in the modern west they're supposed to be heterosexual. People who fail in that dynamic will switch for purpose of creating intimate relations.

  23. Sexually antagonistic coevolution? There are genes that are of advantage to the sisters of male homosexuals that outweigh the disadvantage to their brothers.

  24. some gay men do have biological children, and so perhaps had relationships with women and men in their group. Indeed in Ancient Greece, strong platonic and romantic relationships between men were an accepted part of life, even if those involved had wives and children.

  25. I was brought up in a isolated place where homosexuality was unheard of still when I was 6 my first crush was a guy didn't know what was homosexuality until I was 16 when I searched y do I like guys nd never got interested in women when a lot of girls was flirting with me

  26. So from your evolutionary opinion, when a man is failing on some level (which is decided by a combination of upbringing/biology/environment) to out-compete in an environment of scarcity of high sex market value-sparse, he becomes gay, same with women becoming lesbians – their own failure + supply/demand leads to the gene subprogram triggering, not just as psychological coping of sorts.
    But I don't see how this would keep happening biologically, since they're not reproducing much, unless there have been examples of global competition, in which societies with gays in them out populate societies without. It is likely just the psychological result of upbringing/environment/competition.
    On the other hand a purely biological-leftovers explanation does fit well(or not, depending on how you interpret it) with "Lavender marriage", aka when homo have no trouble findining hetero partners.

  27. You people over think being gay. Who cares what makes someone gay (I hate the word homosexual – sounds like a disease). I always been gay, before I even knew what sex was. When I was a child I'd watch our neighbor mow his lawn with his shirt off and was completely taken with his body – not in a sexual way. His wife could have been naked and it wouldn't have interested me in the slightest. We are what we are, whether it be genetic, or God given – who cares.

  28. He Protecc..
    He Attacc..

    But Most Importantly He Can’t Able To Explain Through Evolution The Hole In Our Buttcracc..

  29. But homosexuality is much more common among other animals than humans? Maybe the evolutionary reason is more complicated than just one answer?

  30. Or there is another option which Richard is too cowardly to explore. Diseases and disorders are also genetic and can be passed down from generation to the next with it expressing itself in the parent. As same sex attraction interferes with a persons ability to reproduce, it is therefore a disorder.

  31. I’m a gay guy and have experienced same-sex attraction since kindergarten. I often used to wonder as a self-hating adolescent, “Why am I like this?” I eventually concluded that since I was incapable of getting a scientific answer, the only satisfying answer was, “…because.”
    A lot of people find such an answer dissatisfying, but when you meditate on it, it really provides a greater overview which facilitates in liberating a person from feeling shame, inferiority, self-hatred, etc about one’s homosexuality. I didn’t choose it. It’s just how things shook out, either in the womb or in the first few years of my life. And in either case, what say did I have? None. Thus, homosexuality is, by definition, natural.

  32. Quite simple why those genes are evolutionarily transmitted. Homosexuality genes in males are passed over by mothers and homosexuality genes in females are passed over by fathers.

  33. so homosexuality didn't exist before bottle feeding? I had a lot of respect for Dawkins before watching this vid.

  34. The usefulness or what have you of homosexuality is irrelevant to the discussion as it has no bearing on propogation. Most likely is that for whatever reason, they are able to mate and have offspring. This shoots the worker bee theory. Also the recency theory is irrelevant because other animals in nature do it. But perhaps they are just doing it because they see humans doing it. 😉

  35. Genetic traits can sometimes be linked through anal sex! Except that as a fact not just a theory.

  36. Two genes at play here. The genes to BE homosexual, and the genes to have the capability to PRODUCE a homosexual. The later is what is significant (if it exists). Studies found that women produce homosexuals when under stress during pregnancy. a Time of stress for early man would be a shortage of resources. A homosexual will provide support to the hominid troop, or hunter gatherer tribe, but won't produce more mouths to feed, reducing the resource related stress on the group, increasing it's chance for survival. That's how the capability to produce homosexuals continues to this day even though it seems self evident that the phenomenon itself would weed itself out via natural selection quite quickly.

  37. Life is not just about birthing. You have to be pretty stupid to believe that the Bible "god" destroyed the world twice when there are no scientific facts to support it. In one instance, only Lot and his two daughters were left in this world. The daughters got Lot drunk to rape him to become "pregnant by father." This is pure rubbish. Noah's Ark is pure thrash because the amount of water on our planet is finite; our planet cannot be covered with water. Adam and Eve's kids mated with each other to grow the population, as did Noah with his family. I see here no morality, just incest and more incest. Tamara was passed on from brother to brother and finally the father-in-law got her pregnant. Gandhi said it right, "I don't like you Christians; you are so unlike Christ." Though "Christians" are so pro-life and "you shall not lie or kill," at the sound of a trumpet Christian George Bush invaded Iraq for its oil killing a million Muslims. Nothing is known about Jesus’s first 30 years of life; thus we can discard the nativity scene and Holy Mary if you get my point. Christian John McCain dropped bombs on the innocent working their rice fields below while in Vietnam. He was no hero; he was a Hitler. A pope and Hitler made a pact to kill 6 million Jews. Who committed genocide against the first Americans? This is not “Christian” country; this is Indian country. The first Americans were not white; they were of Asian descent. Because of the Catholic religion, people in Latin America are becoming dumber than dumber because the average I.Q. has dropped to 90. So you should leave homosexuals alone because anything that the “Bible” says about it is false. Why don’t you just mind your own sexuality? Perhaps you are a closeted homosexual! It is okay for you to come out of the closet. We will embrace you with lots of gay love. Why don’t you respect a woman’s rights to her reproductive choices? There is nothing scarier than “Christianity” because it includes the KKK, the White Supremacists, Mother Theresa and Trump. The Bible was not written or inspired by God. Fools inspired it. God is both Creation and Evolution. Preachers have learned that hate is profitable; they are just after your wages. Give religion no money and they’ll throw you out of the brick-and-mortar building they like to call “the House of God” when is not. There is no Judeo-Christian god! We can begin to bury or burn the Bible in order to make all that fiction and superstitions disappear. Homosexuality has given us Tchaikovsky, Alexander the Great…and Leonardo da Vinci. If you become learned in physics, biology, chemistry, etc., at the university level, you too will discard the old book called “the Bible,” which I get free when I sin in motels with a woman.

  38. Nature invented homosexuality to limit the over-population of this small planet. There are greater things to life than birthing.

  39. It can be good for me to try this. Changing my environment I live with a same sex couple, I have found that I am learning more so to Bisexual less to heterosexual? I naturally feel heterosexual, but am not super manly. Love the question! 🙂

  40. We need homosexuality to halt overpopulation. Parents with four heterosexual sons and have another son, he will be homosexual. The fifth son will be homosexual or in the case of Michael Jackson would be a boy loving pedophile. I don’t know about Jimmy Osmond but my youngest brother certainly is no heterosexual.

  41. Having older brothers increases the probability of hormone levels in the womb being the possible cause?

    Apparently not.

  42. Imagine the year is 5090 now you have evidence of fossilised miniature dinosaurs that shoe various types,shapes and sizes of dinosaurs .(all fossilised toys that have bio degraded )since mankind has destroyed itself in a nuclear holocaust and started all learning afresh there is now concluding evidence that miniature dinosaur had evolved from a primordial soup be were extinct as the fossil records show and to prove there are finds of an actual thigh bone as well as a calf bone (which happened to be chicken bones) now that it's proven mankind can rest assured that God does not exist .An ass of a theory compounded by an even bigger more dumbass pretend scientist who has found a way to fool the world and make lots of money doing it.

  43. I am thoroughly Darwinian and I must say that this "explanation" is ridiculously chimerical.  Don't bow to political correctness.

  44. Religious insanity aside, homosexuality is a genetic defect.  Unaesthetic and degenerate, it would better suffer derision than gain acceptance.   Why is retardation naturally selected?  It isn't!  Sometimes nature just lays an egg.  Laugh and just move along.

  45. In other words, one isn't born homosexual, however one can be born with a natural prone to homosexuality which is amplified under an appropriate environment.

  46. So there is no Gene – just some hypothesis (ideas) of how it may have cane about through Darwinian evolution. It's not biology but physiological/neurological. Thanks Richard.

  47. Dawkins is always great for a laugh. Shame biologists don't talk to synthetic chemists about the impossibilities of Darwins theory.

  48. The only possible theory of the three is the latter, but the environmental factor that has would cause the gene to be expressed has been present for a very long time, across many different types of environments. Given the very high probability of the environment 'triggering' that gene, you would expect the probability that a person's gene is not activated to be very low, meaning that over time, the amount of people with that gene would have to decrease. Probability of both occurrence and survival seem to be the central mechanisms for Darwinian evolution, so this skewed probability also discredits the third theory. Maybe I am wrong. I don't think the topic matters much from a biological perspective. The moral perspective is much more important. But it seems like the evolutionary explanation for it is weak.

  49. Richard, Richard, Richard… you're really reaching here.
    A much simpler explanation is sexuality in males is all about domination. A homosexual male knows offspring are needed for various purposes: to take care of you as you age, heirs, future protection, etc.
    So a homosexual male will keep their homosexuality on the down low. If a leader is homosexual, is their victim going to say, "hey the chief raped me!" Don't think so.
    Humans, unlike animals, do activities which aren't instincts, and instead out of a necessity for greed. It seems humans evolved to be the greediest, and still efficiently exploit. Which was made much easier with the invention of capitalism and fake democracy to fool us.

  50. Could it be that an environment which is more ‘homosexual friendly’ can cause the homosexual gene to manifest itself more often than the one where homosexuality is looked down upon? for example, a pregnant woman in the west is more likely to bare a gay child compared to if she were living in, say, the Middle East

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