pffft, hold your horses...
I guess so, but I think you should start the new thread. Unless you want to continue it here.
And what exactly is the thesis? I guess from what I know humans are equally influenced by nature and nurture. My teacher presented a study for my sex differences class, I think http://www.madsci.org/posts/archives/aug97/862927470.Ge.r.html" is the same one:
Genetic influence for homosexuality?
They looked at the pedigree for male homosexuals to see if it ran in the family. They found that Researchers found that the concordance rate for homosexuality is highest among identical twins, lower among fraternal and lowest in adopted siblings. Such a pattern is evidence for a genetic basis to homosexuality... the closer you are genetically to your sibling, the more likely you both are to be gay. If you are not genetically related, you are less likley to both be gay, even though you grew up in the same home. However, it should also be stressed that the researchers found aconcordance rate of around 50% for both gay and lesbian pairs of identical twins... *not* 100%. In other words, half of those with an identical twin who is gay are also gay, half are not. This probably means that, although genes play a role in sexual orientation, they are likely *not* to be the only factor, as they are for traits like eye and hair color.
The final piece of evidence comes from studies on gene linkage. Remember the pedigree analysis that suggested a gene for male homosexuality on the X-chromosome. To review some basic genetics, girls inherit 2 X-chromosomes, one from each parent. Boys get an X-chromosome from their mother, and a Y-chromosome from their father. The fact that gay men tended to have more gay relatives on the mother's side than on the father's suggested that, if homosexuality was inherited, the gene would be on the X-chromosome.
So there is a link, just not a really strong one. Plus, there aren't any studies for women. There are other studies that claim male homosexuals have "female" looking brains, eg the INHA3 and studies on how lower levels of testosterone in the womb are related to this (related to sexual preference). But what about females? Do lesbians have brains that look like males?
Oh, found it, here's my notes on the study (http://www.nuffieldbioethics.org/go/textonly/browseablepublications/geneticsandhb/report_418.html" )
Percent indicates the proportion of siblings that were both homosexual
_______________________Male____________________Female
identical twins___________52%______________________48%
fraternal twins___________22%______________________16%
adopted siblings__________11%______________________6%This also relates to a book I read by http://en.wikipedia.org/wiki/Bryan_Sykes" )
edit: he also says he's not sure, but it was just a hypothesis that helped to explain it in part.
Should I move this to a new thread?