arcticpenguin said:
Hi, A/P,
But those influences would be cultural, not biological. Frankly, this one is a pompous clown who is already past the limits of his knowledge. He'll have to do more than proclaim and gainsay to make any headway.
Cheers,
Is homosexuality genetic?
- Thread starter Drooper
- Start date
-
- Tags
- genetic homosexuality
Hi, A/P,
But those influences would be cultural, not biological. Frankly, this one is a pompous clown who is already past the limits of his knowledge. He'll have to do more than proclaim and gainsay to make any headway.
Cheers,
arcticpenguin
Philosopher
- Joined
- Sep 18, 2002
- Messages
- 5,687
Not necessarily, could be chemical and therefore biological. Influence of hormones in the womb, that sort of thing. Agreed on the other point.BillHoyt said:
I read somewhere that the fetus is female before it is bathed in a certain hormone, I believe testosterone which causes the fetus to take on male secondary charactoristics. The baby was genetically XY before hand, but it's not clear how the hormones "know" which fetus to bathe the hormone with. Does this make any sense?
Denise said:
Worshipful one,
I think you mean primary sexual characteristics. The adam's apple, deep voice, beard and ability to guzzle great quantities of bad beer are the secondary sexual characteristics. The hormones are triggered during the gonadal differentiation phase of embryological development. The genes for those hormones reside on the Y chromosome.
Cheers,
BillHoyt said:
Yep, you got me. I was thinking penis and testes which, of course, are primary.
At least to most men anyhow from what I've heard.Anyhow, is there any measurable differences attributable from testosterone on homosexual vs heterosexual males?
spoonhandler
Unregistered
S
Can we consider the possibility that rather than one obvious mutation in one gene, the combination of more subtle differences is at work? Slightly lower or higher expression of any number of genes, slightly better or worse binding affinities on certain receptors and so on, would have no impact on the overall viability of the affected organism, but may change behaviour.
Also, for evolution to somehow eliminate a particular mutation/behaviour, there needs to be selective pressure. What pressures do humans face that would delete such a hypothetical gene or mutation?
Also, for evolution to somehow eliminate a particular mutation/behaviour, there needs to be selective pressure. What pressures do humans face that would delete such a hypothetical gene or mutation?
Drooper said:
No, as already mentioned by others. You are focused on the fact that homosexuals don't reproduce. First, this is not a true statement. Second, the relevant question is "do people which the hypothetical gene repreduce"? which is entirely different.
Further, it is a mistake to confuse "evolutionary advantage" with the actual mechanisms of evolution (random mutation, natural selection) . There is nothing that requires the adaption to be "useful" according to a simple, easily understood and objective criteria. Many - if not most - mutations have no discernible benefit for the species. Obviously, some do.
However, I think the research on the genetic component of homosexuality leaves a lot to be desired. It is a bit hard to get at without a coherent theory of human behavior to work against.
As I asked earlier in the thread, what kind of studies have been done in homosexual non humans? Do they reproduce usually? Why is it that the denser the human population, the higher percentage of homosexuals? Is that true in the animal kingdom as well?
I am not a biologist. In fact, my knowledge of genetics is limited to three years (only) of various courses that are somewhat related to the topic.
I have never, in my entire life, thought 'hey, I want to have sex with men and alienate myself from a large portion of the population'
Not once. It wasn't a choice. So it must be something else.
I have never, in my entire life, thought 'hey, I want to have sex with men and alienate myself from a large portion of the population'
Not once. It wasn't a choice. So it must be something else.
Titananarchy
Unregistered
T
BillHoyt said:
Bill, you were replying to my statements about mammalian reproduction. It is not a straw man to say that your statements that something can be biologic without having a direct genetic cause. You have made a statement that I believe to be false. I have not misrepresented your argument.
Absolutely, but later. I'm busy but I will try to return to this later today or tomorrow with evidence of how a biological difference can happen without a direct genetic cause in humans, and in a burst of keeping to the subject of the thread, how homosexuality (or come to think of it) heterosexuality arises in humans.
Cheers.
Shane Costello
Graduate Poster
- Joined
- Aug 8, 2001
- Messages
- 1,232
As someone with a growing knowldege of genetics, led me add my tuppence worth.
IMO it's going to be difficult to measure any genetic influence on sexual preference without having a reliable and reproducible measurement of the phenotype, in this case homosexuality. Neither is it likely that there would be a single gay gene, rather a number of genes expressed together would influence sexual preference one way or the other.
Homosexuality has been accepted and practised to varying degrees throughout history. AFAIK it was very prevalent among the ancient Greeks, but that it went hand in glove with heterosexual relationships. I'd imagine that with the advent of Christianity and the role played by the Church in Greek society that homosexuality was frowned upon. It's hard to see how genetics could have influenced this about change.
In some species only a few animals in a colony or wider group assume reproductive duties. Last week's edition of "New Scientist" did a feature on this, and I'll get back to it when I have time.
IMO it's going to be difficult to measure any genetic influence on sexual preference without having a reliable and reproducible measurement of the phenotype, in this case homosexuality. Neither is it likely that there would be a single gay gene, rather a number of genes expressed together would influence sexual preference one way or the other.
Homosexuality has been accepted and practised to varying degrees throughout history. AFAIK it was very prevalent among the ancient Greeks, but that it went hand in glove with heterosexual relationships. I'd imagine that with the advent of Christianity and the role played by the Church in Greek society that homosexuality was frowned upon. It's hard to see how genetics could have influenced this about change.
In some species only a few animals in a colony or wider group assume reproductive duties. Last week's edition of "New Scientist" did a feature on this, and I'll get back to it when I have time.
a_unique_person
Director of Hatcheries and Conditioning
since humans are social animals, it could well be that we need the 'gays' to perform essential societal functions.
Titananarchy said:
I'm afraid you really put the dash in the balder again. Here is the exact exchange of posts:
I repeat again: I have not said homosexuality is caused by genetics. Your statement clearly implies I made a genetic claim about human homosexuality. I have not. I have attempted to shed light on what seems to be a common misconception about how selection works.
And on that point, before we go any further, are we agreed that your claim about lethal genes was in error?
Cheers,
In haplo-diploid species like ants and bees, the non-reproducing members are acting in their best genetic interests by aiding their siblings, to which they are more closely related than they would be to their offspring.
It's not going to help to explain homosexuality in humans.
I'm curious about where this (1994) research ended up:
These guys evidently studied only male homosexuals. Even if we establish that male homosexuality has a biologicalgenetic cause, I wonder if homosexuality among females will be traceable to the same cause.
arcticpenguin
Philosopher
- Joined
- Sep 18, 2002
- Messages
- 5,687
Once again, you have all the answers, but fail to reveal them. Put up or shut up, troll boy.Titananarchy said:
There are two parts to the "any homosexual allele should have been eliminated" hypothesis:
o the presumed homosexual allele is recessive
o homosexuals don't reproduce
The errant conclusion is: the allele should have been eliminated.
First of all, the second premise isn't universally true. Secondly, if it were true, it still would not effectively eliminate the homosexual allele. Directional selection would, at best, reduce the homosexual allele frequency to its mutation-selection equilibrium value -- the point at which the rate of new homosexual alleles being introduced by mutation equals the rate at which these alleles are being removed by selection.
Cheers,
phobos
Unregistered
P
Denise said:
Hypothesis: it isn't. The percentage of _out_ homosexuals will be higher in a region of denser population. If I'm gay and living somewhere sparsely populated, I'm unlikely to meet out gays very often, I'm unlikely to be part of any gay community. I'm therefore going to be reluctant to come out myself.
On the other hand, if I'm gay and in a major city, I'm going to encounter other gays much more frequently. I'm going to realise that there's a whole gay subculture. Therefore I'm far more likely to have the confidence to come out.
If anyone in this thread is _actually_ gay... comments?