Homosexuality and Natural Selection

[carlosMM]

If homosexuality is genetic, which I'm pretty sure its not, it could have survived this long because very little gay men in the past didn't have wives and children.

Still, I'm pretty sure it has to do with hormones received as a fetus.

OK, now I can't help but getting dragged into this again:

As I have posted about 7 times on this forum already, it is a mix of the two: genes control the homrmone levels, but outside circumstances and health do, too.

So there is a genetic and other influences.

 

[JohnRM]

google it, I don't want to spend my time researching for you. I've already done it enough on this forum. The information is out there all you have to do is look.

Well, I googled it and I fail to see how one could prove that it was fetal horomones. What did they do, measure the horomones and track these children until they started having sex, "Are you gay?"

It sounds like a theory to me...

Furthermore, I would like to quote it...

Still, cautioned Breedlove, biology does not determine sexual orientation.

I mean, c'mon the very science you use to support your claim has been just quoted as saying that biology DOES NOT determine sexual orientation. You're gonna need a bigger paddle for this crap creek.

 

[carlosMM]

...........

Yes yes yes, give me some time to find the article that shows what happenes with mice and rats....

btw, I remember that there is a LINK posted earlier in this thread to it, so while I look for the PDF you cna look for the link.

 

[carlosMM]

this is the best I can do so quickly:
http://salmon.psy.plym.ac.uk/year1/sexdiff.htm

and this:

In rats, exposure to prenatal androgens will make a female rat behave just like a male. As an adult, she will fight with males and mount other females. Studies have also shown that if a pregnant rat is subjected to extreme stress during pregnancy, this causes release of stress hormones into the blood which can block the effects of testosterone in the developing male rat’s brain. The result is that the male rat is physically a normal male, but exhibits homosexual behavior as an adult. He is attracted to other males, and assumes the female position in the presence of other male rats.

Can this also happen in humans? Intriguing evidence comes from a study of men born in Germany during the highly stressful period of WWII compared to men born either before or after WWII. The study found a much higher rate of homosexuality among men born during WWII than in men born either before or after the war, supporting this idea. However, this cannot explain all instances of male homosexuality, because most mothers of homosexuals do not report unusual stress during pregnancy. So other factors must be involved.

from http://www.hss.bond.edu.au/psyc12-214/lectures/week9notes.htm

contact someone who made these lecture notes and ask for the citations. I do not have access to the biology online database from here, only geology.

 

[carlosMM]

Well, I googled it and I fail to see how one could prove that it was fetal horomones. What did they do, measure the horomones and track these children until they started having sex, "Are you gay?"

It sounds like a theory to me...

You cna see it in rats - even without artificially changing the testosterone level.

Rats have two uteri and up to 14 embryos in them - usually roughly half male and half female. Testosterone can diffund freely, thus if there are males and females next to each other in a 50:50 ratio all of them get their own testosterone and an even dose from their neighbours. If you check those litters where there are e.g. 10 females and 1 male you will usually find the male homosexual - he got too little from neighbours.
Equally, if the girls are in the minority (or if one female happenes to end up between all the males in the litter) you will find them aggressive, muscular, bold - and usually unwilling to mate with males.

 

[andrewgprv]

Well, I googled it and I fail to see how one could prove that it was fetal horomones. What did they do, measure the horomones and track these children until they started having sex, "Are you gay?"

It sounds like a theory to me...

My first post in this thread started with saying that no one knows for certain, there are alot of theories and that I believe the womb theory has the most credence. But if you would like to believe it is a choice go ahead. But it is a choice I didn't make.

 

[andrewgprv]

Well, I googled it and I fail to see how one could prove that it was fetal horomones. What did they do, measure the horomones and track these children until they started having sex, "Are you gay?"

It sounds like a theory to me...

My first post in this thread started with saying that no one knows for certain, there are alot of theories and that I believe the womb theory has the most credence. But if you would like to believe it is a choice go ahead. But it is a choice I didn't make.

You obviously didn't so much researching. Most of the research has been done with animals, rats, sheep, flies etc...

 

[10Seven]

Well, I googled it and I fail to see how one could prove that it was fetal horomones. What did they do, measure the horomones and track these children until they started having sex, "Are you gay?"

It sounds like a theory to me...

Furthermore, I would like to quote it...



I mean, c'mon the very science you use to support your claim has been just quoted as saying that biology DOES NOT determine sexual orientation. You're gonna need a bigger paddle for this crap creek.

The quote is opinion, not proof - there remains a strong suggestion as to a genetic component in 'deciding' sexuality.

Simply because the genome has been mapped, doesn't mean we can read even a 10th of it...


To the opening question, I would suggest some parallels, such as myopia, life threatening birth defects, etc, etc, etc.

Homosexuality, also, does not preculde reproduction, especially in societies which do not accept that sexuality.

 

[Stapel]

If homosexuality is not a choice and indeed caused by certain genetic factors, how come gay people haven't been wiped out yet by natural selection? Surely if genes are to blame, then men who have sex with other men (clearly) don't reproduce and therefore don't pass on the gay gene. If they don't pass on the gay gene, then the resulting population will be entirely free of the gene.

Scientists have found STRONG similarities in gene-combinations at male homosexuals, which cannot be found at male heterosexuals. These pieces of similar code were found in one and the same chromosome:
The X-chromosome.
All men (and women) get this chromosome from their mother, and from their mother only.

An important remark:
Not all homosexaulity is caused by the same causes. I guess the combination of genes found on the X-chromosome, that heavily correlates with men being gay, might cause over half of it.
Another cause might be the womb theory, which I (personally) find doubtful. Others (very few) will simple choose to be.. Just like some 'hard-coded' gays might choose to live as heterosexuals.