the gay gene?

[Independent Vision]

the main subject of my initial post was to seek more insight into the possibility of genetics playing a role in sexuality. i do understand that there are many other contributing factors and it can't simply be genetics, but i think there is a possibility that a predisposition to attraction of pheromones produced by the same sex may be a factor. as for posting wiki links...i think the last link in particular has already been referred to in this topic about 3 or 4 times.

Yeah, but I couldn't very well post the information without the link, could I?

Sure, some might be genetics, and as such the Benevolent Uncle is a good explanation for where it would be good for natural selection. *shrugs*

 

[Andiferous]

The thing everyone seems to be forgetting is that we have sex because it is pleasurable. Producing offspring is a side effect. Granted, this probably was not always the case, but it seems that at least for most mammals, we have sex because we enjoy it.

I really like this way of putting it. The fact is that sexuality is influenced by a number of different factors working in combination, and I can't see any way of simplifying it into a few strands of DNA. Physiologically, psychologically and hormonally, pleasure differs from individual to individual. And to support your point further, masterbation obviously serves no obvious evolutionary advantage, either.

real question should be is male/female pair bonding for life (forsaking all others) natural? It seems rare in the animal kingdom and human history. Nevertheless, for some reason in western cultures we seem to think it is the norm.

I love this point as well.

-evolution happens to populations, not individuals

Excellent to point out.

Frankly. If humans were selected to have lots of babies, I can't see why it would be so difficult for so many females to give birth, and for birth control to be so very popular. Maybe the population was "selected" to have fewer babies at longer gestations and more parental involvement... No way of knowing for sure.

 

[iamthedinger]

The thing everyone seems to be forgetting is that we have sex because it is pleasurable. Producing offspring is a side effect. Granted, this probably was not always the case, but it seems that at least for most mammals, we have sex because we enjoy it.

again, just to throw it back into the mix, homosexual activities are not only observed in human beings, and only a few species of animal actually have sex for pleasure. i however am glad to be a part of that few species.

believe me, i practiced a lot before producing a transitional form with my wife....and he's the cutest baby evar!!

 

[Giliell]

I really like this way of putting it. The fact is that sexuality is influenced by a number of different factors working in combination, and I can't see any way of simplifying it into a few strands of DNA. Physiologically, psychologically and hormonally, pleasure differs from individual to individual. And to support your point further, masterbation obviously serves no obvious evolutionary advantage, either.

I'll take this a step further: no procreative sex MUST have an evolutionary advantage or else it would have been wiped out. Because it's not free just because you don't have to feed the brats resulting from it. It costs you energy and in a population that is often 2 meals from starvation, this would be a big disadvantage. So it must have an advantage that's bigger than the energy lost. A dog knows perfectly well when a female is ovulating, only it doesn't stop it from trying to fuck legs, chairs, other male dogs, the postman. Humans have lost that ability (to sense ovulation, not to fuck the postman, obviously) during evolution. No need for it when you're at it anyway.

Frankly. If humans were selected to have lots of babies, I can't see why it would be so difficult for so many females to give birth, and for birth control to be so very popular. Maybe the population was "selected" to have fewer babies at longer gestations and more parental involvement... No way of knowing for sure.

I think that there's a lot of evidence to support that.
But before we get to that a factual correction: human gestation is rather short. Our babies are horribly underdeveloped compared to our cousins' babies. But that damn big head just makes it impossible to get them out later.

1) The grandmother hypothesis
There's the curious pecularity with humans called menopause. Some day, women just stop ovulating, but they don't fall over and die. The grandmother hypothesis states that because of the difficulty and dangers of human gestation and births, and the fact that the quality of the offspring decreases the older the mother gets, it was advantageous to stop ovulating yourself and instead to care not only for the smaller children you have (who'd have less chances if you died in childbirth), but also for your grandchildren who's then have an advantage in survival.

2) Lactation keeps you from ovulating
Breast-feeding acts as a natural contraceptive, because the hormones released while the babe is at it stop ovulation.
Having "only" 2 children within 3 years seems to have been better than having 3-4 children during that same time because their chances of survival and having a good start were better.
Disclaimer: Don't do this at home. The timespan is different for every woman and you have no clue when your first post-natal ovulation takes place since that's 2 weeks before your first post-natal menstruation

3) twins and triplet are pretty rare and had very little chances before the age of science and medicine. Too bad octomom didn't live 100 years ago

 

[judomuerte]

/derail (slightly)

After reading this thread, I've come up with a few questions.

1. How is the uncle hypothesis selected for?

2. What is the real difference between sex for pleasure and procreation? Wouldn't pleasure (mental, instinctual) be derived from the act itself, regardless of the physical pleasure we humans (and some other mammals) attach to it? Why else are all creatures driven to procreation if not for the positive reward?

I also have a hypothesis for homosexuality being selected for, under the assumption the gay gene exists and is transferred genetically. I would say that the very religions that shun the act are the very progenitors of the characteristic. It shames them into either hiding their homosexuality and mating with a female, or lying to themselves and mating with a female (or vice versa of course). Under this assumption, and the assumption that it is more genetic then memetic, with the fall of religion, even the liberalization of the dogma in regards to condemnation will allow for natural selection to select against homosexuality.

This is easily falsified by the continuation of instances of homosexuality once religion is no longer in such control (praise FSM) and negated with in vitro fertilization.

3. Has the physical vs pheromone attraction been tested conclusively? Are they both causative in regards to attraction? I guess I'm asking if the pheromone question is even relevant in the first place.

 

[Giliell]

/derail (slightly)

After reading this thread, I've come up with a few questions.

I'm wondering whether you really did, because if you had you'd have found the answers to your questions.

1. How is the uncle hypothesis selected for?

In short: by having an additional capable adult who earns food for the brats. Less but better cared for kids, more successful than having lots of dying babies.

2. What is the real difference between sex for pleasure and procreation? Wouldn't pleasure (mental, instinctual) be derived from the act itself, regardless of the physical pleasure we humans (and some other mammals) attach to it? Why else are all creatures driven to procreation if not for the positive reward?

Ehm, I don't understand your question, what exactly should the difference between physical and mental pleasure be and how would that matter?
The difference between sex for pleasure and sex for procreation is, considering our inablility to tell one from the other is, for us, nonexistent (largely). In evolutionary terms, sex costs energy and carries risks. So, if non-procreative sex doesn't have benefits, it is a disadvantage. There are animals that can tell the difference and that only engage in procreative sex (polar bears, for example).
Why are we driven towards procreation?
Ever heard of the selfish gene? Only the genes of animals that procreate get passed on, so that's the main Positive reward.

 

[judomuerte]

I'm wondering whether you really did, because if you had you'd have found the answers to your questions.

This makes no sense, but who cares. Maybe I'll get an answer.

In short: by having an additional capable adult who earns food for the brats. Less but better cared for kids, more successful than having lots of dying babies.

Citation please? This seems highly untestable. I'm not trying to be difficult, but this is exactly why I asked the question. I understood the premise...

Ehm, I don't understand your question, what exactly should the difference between physical and mental pleasure be and how would that matter?
The difference between sex for pleasure and sex for procreation is, considering our inablility to tell one from the other is, for us, nonexistent (largely). In evolutionary terms, sex costs energy and carries risks. So, if non-procreative sex doesn't have benefits, it is a disadvantage. There are animals that can tell the difference and that only engage in procreative sex (polar bears, for example).
Why are we driven towards procreation?
Ever heard of the selfish gene? Only the genes of animals that procreate get passed on, so that's the main Positive reward.

I was simply stating that sex for procreation is pleasure. Humans (and some others) have developed a physical pleasure that is attached, but how is the satisfaction that comes with completing an instinctual urge/desire not considered pleasure? I was referring to the immediate reward, as I'm perfectly aware of how natural selection works. I get the feeling you think I'm trying to play devil's advocate or the like, in reality I'm really just curious, not daft.

 

[Giliell]

This makes no sense, but who cares. Maybe I'll get an answer.

Might I suggest that you formulate your questions more precisely the first time?
Because:

Citation please? This seems highly untestable. I'm not trying to be difficult, but this is exactly why I asked the question. I understood the premise...

is not what you asked before. You asked "how is it selected for?", which asks for the mechanisms which I had explained earlier.
I'm really bad at reading other peoples thoughts, but since now you're asking for citation:
http://www.newscientist.com/article/dn13674-evolution-myths-natural-selection-cannot-explain-homosexuality.html
http://www.newscientist.com/article/mg19626281.500-evolution-survival-of-the-selfless.html
http://www.talkorigins.org/indexcc/CB/CB403.html

I was simply stating that sex for procreation is pleasure. Humans (and some others) have developed a physical pleasure that is attached, but how is the satisfaction that comes with completing an instinctual urge/desire not considered pleasure? ...I'm really just curious, not daft.

That's why I asked you to reformulate your fucking question.

I'd say that sex is pleasure. FULL STOP
Because we have no fucking clue whether it is procreational or not, at least not without a lot of monitoring. I'd go further and say that our discovery that sex leads to procreation has probably taken a lot of fun out of it.
Nobody denies that sex is pleasure and leads to procreation, but just for the latter we don't need to have that much of it. 2 times at the right time of the months would totally last, which means that there has to be an additional factor to it.

 

[Independent Vision]

I'd argue that IF sex for us would be for procreation we'd go into heat. Not have these small periods of ovulation that does have an effect, but nowhere near what cats, for example, goes through where they just HAVE to mate and will present themselves to everything and anything.

 

[judomuerte]

Citation please? This seems highly untestable. I'm not trying to be difficult, but this is exactly why I asked the question. I understood the premise... is not what you asked before. You asked "how is it selected for?", which asks for the mechanisms which I had explained earlier.
I'm really bad at reading other peoples thoughts, but since now you're asking for citation:
http://www.newscientist.com/article/dn13674-evolution-myths-natural-selection-cannot-explain-homosexuality.html
http://www.newscientist.com/article/mg19626281.500-evolution-survival-of-the-selfless.html
http://www.talkorigins.org/indexcc/CB/CB403.html



I was simply stating that sex for procreation is pleasure. Humans (and some others) have developed a physical pleasure that is attached, but how is the satisfaction that comes with completing an instinctual urge/desire not considered pleasure? ...I'm really just curious, not daft.
That's why I asked you to reformulate your fucking question.

I'd say that sex is pleasure. FULL STOP
Because we have no fucking clue whether it is procreational or not, at least not without a lot of monitoring. I'd go further and say that our discovery that sex leads to procreation has probably taken a lot of fun out of it.
Nobody denies that sex is pleasure and leads to procreation, but just for the latter we don't need to have that much of it. 2 times at the right time of the months would totally last, which means that there has to be an additional factor to it.

First, thanks for the links. It really makes me wish I could afford subs.

Secondly, you should have typed in all caps, cuz then I would've really understood you were irritated at me.

In regards to explaining natural selection as "how it is selected for" I guess I was asking for a particular postulation. How is the benevolent uncle gene reproduced if it is systematically culled through non propagation?

I realize it isn't your job to teach me these things, that and you make for an angry teacher. Thanks for your time.

 

[Giliell]

First, thanks for the links. It really makes me wish I could afford subs.

Secondly, you should have typed in all caps, cuz then I would've really understood you were irritated at me.

I hate all caps

In regards to explaining natural selection as "how it is selected for" I guess I was asking for a particular postulation. How is the benevolent uncle gene reproduced if it is systematically culled through non propagation?

I realize it isn't your job to teach me these things, that and you make for an angry teacher. Thanks for your time.

You'Re welcome, I find the topic highly interesting.
AFAIK, the genes get transmitted by the offspring of the siblings. I'm not a scientist and my overview and knowledge of that topic is purely that of an interested layperson, but it seems like being something where the expression of genes comes into play, so all kids have it, but it only gets expressed in some

 

[Andiferous]

I agree Giliell.

Actually, the pleasure idea and the earlier question about whether or not sex was used as a social tool brings up another question: are we assuming that everyone has a choice of mates when speculating evolutionary trends?

Sexual dimorphism in many species (or that one sex is very different from the other) tends to show different selection trends for either sex. Also, many species where males are a great deal stronger than females tend to be male-centric societies; like silverback gorillas or lion prides. In this case, competition is so intense that only the largest competitor is likely to reproduce. Even so, it's unlikely the females had any choice in their mate, and they are probably not keen on the elimination of their previous offspring by the dominant male.

So sex is often for pleasure, but not always. Sometimes it's just expected. I do wonder if in these more tightly controlled societies there is less freedom for expressing one's sexuality at all, and less homosexual behaviour observed. This seems to be the case in human society.

 

[Giliell]

So sex is often for pleasure, but not always. Sometimes it's just expected. I do wonder if in these more tightly controlled societies there is less freedom for expressing one's sexuality at all, and less homosexual behaviour observed. This seems to be the case in human society.

That's an interesting question
Disclaimer: pure speculation here, no science or citation avaible
If we look at human societies all over the world and time, polygamy seems to be a trend but also (temporarily at least) monogamy. Quite often only the really, really rich "alpha male" gets a real harem while most get a partner and some (thanks to the big guy with the harem) don't get a woman at all.
But not all societies look upon homosexuality as sinful.
It seems to be an idea that is most persistent in societies obsessed with breeding. Homophobia seems to be the little sister of misogyny. And if I look at some trends in the USA at the moment, where the Rethuglicans try a massive rollback on reproductive rights and at the same time being at least prejudiced against gay people, it seems to be true

 

[judomuerte]

I started looking into homosexuality as viewed by primitive cultures, to make a correlation between religion and homosexuality. I'm still reading, but here's a great link with lots of reading. From what I've read so far, there seems to be a general acceptance in more primitive cultures, especially in relation to bisexuality. Also in some cases, in encouragement.

http://semgai.free.fr/doc_et_pdf/africa_A4.pdf

 

[Andiferous]

So sex is often for pleasure, but not always. Sometimes it's just expected. I do wonder if in these more tightly controlled societies there is less freedom for expressing one's sexuality at all, and less homosexual behaviour observed. This seems to be the case in human society.

Homophobia seems to be the little sister of misogyny.

Yes, yes yes... was afraid to say so succinctly out loud.

All well put.

 

[Proteus]

I'd argue that IF sex for us would be for procreation we'd go into heat. Not have these small periods of ovulation that does have an effect, but nowhere near what cats, for example, goes through where they just HAVE to mate and will present themselves to everything and anything.

Really, I'd argue just the opposite. Other apes ovulate, like we do and have a variety of reproductive strategies. Since ape females can get pregnant at any season of the year and have the intelligence to determine when would be most advantageous that presents two selective advantages. Potentially three considering humans, chimps, and bonobos often use sex as a social bonding tool and as a way to keep males around to help take care of the young.

 

[Giliell]

Since ape females can get pregnant at any season of the year and have the intelligence to determine when would be most advantageous...

Do they?
Sorry, but I don't think so. That's why human parents one day have to give "the talk". That's why we need sex ed. That's why "natural family planning" requires a hell lot of work, data records and some devices other apes just don't have.

In fact, it's one of the things I wozld really, really want to know but we most likely never will: When did our ancestors find out the link between sex and pregnancy?

 

[Baranduin]

Since ape females can get pregnant at any season of the year and have the intelligence to determine when would be most advantageous...

Do they?
Sorry, but I don't think so. That's why human parents one day have to give "the talk". That's why we need sex ed. That's why "natural family planning" requires a hell lot of work, data records and some devices other apes just don't have.

So? As cultural animals, there's no need for the females to know the link but just a culturally transmitted belief or superstition. Young apes would observe and learn the behavior of their adults (a mom rejecting sex with other apes while they have a young baby, or "not being on the mood" in rainy days, etc; that added to a purely biological imperative - it wouldn't surprise me much - that in times of tribulation, stress and insecurity libido may go down). Those with the "correct" (note the marks) set of beliefs would reproduce more successfully and overcome neighboring groups with a less efficient policy, transmitting the "memes" both vertically and horizontally. As proto-humans would become more humans, this would evolve to become full cultural items (I can see how protoastrology, etc could have evolved from those practices, and how protoreligions could have exapted them - origin of rituals of fertility, and of the control and submission of the women, anyone?).

Eventually the link between sex and offspring would be discovered, and as humans became less dependent of their instincts and more dependent on language, and as technology was created to make our reproductive success less dependent of the environment, and as our knowledge and comprehension of these issues deepened, thinks like 'the talk', 'sex ed', etc became important for our culture. I don't see how being informed, consenting, etc, are important for the reproductive success (though they are the moral thing to do).

Anyway, I have no idea if this just-so story has any resemblance with what actually happened in reality, I'm just bringing it forward because it drives me nuts the idea that less cultural species has no complexity because they don't have the complexity of our modern society.

In fact, it's one of the things I wozld really, really want to know but we most likely never will: When did our ancestors find out the link between sex and pregnancy?

I guess it didn't took much: hunter-gatherers probably observed that birds nested in pairs, male and female, and so did vermins, etc. Another story, of course, would be the actual mechanism... Is there any data about that?

--

Sexual dimorphism in many species (or that one sex is very different from the other) tends to show different selection trends for either sex.

This has reminded me of a call it hypotheses I saw once - sorry I can't be more precise . The basic idea was that both men and women carried the genes determining the sexual preferences of both male and female, and it was the sex of the offspring what inhibited one set of preferences or the other. In homosexuals, the system was botched (for any reason) so males ended expressing some preferences destined to their daughters, and viceversa.

Could that be?

I'm more of the idea that we have a general and rather reduced set of sexual preferences codified in our genes but that the main drive is cultural (as Squawk mentions), but I'd rather prefer if someone could assess its likelihood before just dismissing it.

 

[TheFlyingBastard]

On the "evolution only occurs in populations thing", isn't that a bit misrepresentative of the process?

I mean, there is selection pressure on individuals, but the genes need to become fixated before we can include it into the evolutionary line of a species - that is, before it even starts to matter in the grand scheme of things. Isn't this thread giving evolution on the individual scale too little credit?

 

[Giliell]

So? As cultural animals, there's no need for the females to know the link but just a culturally transmitted belief or superstition. Young apes would observe and learn the behavior of their adults (a mom rejecting sex with other apes while they have a young baby, or "not being on the mood" in rainy days, etc; that added to a purely biological imperative - it wouldn't surprise me much - that in times of tribulation, stress and insecurity libido may go down). Those with the "correct" (note the marks) set of beliefs would reproduce more successfully and overcome neighboring groups with a less efficient policy, transmitting the "memes" both vertically and horizontally. As proto-humans would become more humans, this would evolve to become full cultural items (I can see how protoastrology, etc could have evolved from those practices, and how protoreligions could have exapted them - origin of rituals of fertility, and of the control and submission of the women, anyone?).

Hmmm, you don't know much about the biological realities of reproduction.
It's not meant as an insult, just as something I notice from the examples you give.
For example, evolution provided a wonderful mechanism that lets us have sex while nursing an infant without risking the health of this infant or a younger sibling by getting pregnant again too soon. Lactation provides hormones that prevent women from ovulating.
You can see how this happened: In our ape group all women had sex soon after childbirth. Some had this mechanism that kept them from getting pregnant soon again.
Now you should think that natural selection would wipe out the non-ovulating females since they have fewer pregnancies, but the survival chances of those fewer kids were better.
I also don't understand what "no sex on rainy days" should indicate, but your hypothesis is missing a starting point: If the young apes learn by imitation from the old apes, who taught the old apes? It's turtles all the way down, because at some point, you either need a biological factor like the lactation-ovulation, or you need knowledge about how the whole shit works.

Eventually the link between sex and offspring would be discovered, and as humans became less dependent of their instincts and more dependent on language, and as technology was created to make our reproductive success less dependent of the environment, and as our knowledge and comprehension of these issues deepened, thinks like 'the talk', 'sex ed', etc became important for our culture. I don't see how being informed, consenting, etc, are important for the reproductive success (though they are the moral thing to do).

Yes, one day it was discovered. I'm guessing that first the link between menstruation and pregnancy would be discovered, that only menstruating females could become pregnant. And they would discover that only those who had sex could become pregnant. But the connection between that one time of sex that led to a pregnancy, that was the real trick, I think.
No, knowing this doesn't matter much in the reproductive process. It rather matters in not procreating. That's why I argued against "ape females would know when to best present themselves" Seems like the cat knows, avoiding all the problems associated with our complicated mating rituals and all the energy we're wasting on the non-procreative sex.


Anyway, I have no idea if this just-so story has any resemblance with what actually happened in reality, I'm just bringing it forward because it drives me nuts the idea that less cultural species has no complexity because they don't have the complexity of our modern society.

I guess it didn't took much: hunter-gatherers probably observed that birds nested in pairs, male and female, and so did vermins, etc. Another story, of course, would be the actual mechanism... Is there any data about that?

What, you think that they deducted from birds to humans? Seems a bit far fetched to me.
It's because individuals don't evolve. End of story.
You are what you are, you either procreate more than the average or you don't. Or do you mean the "individual original bearer of a certain trait"?