RE: Christian couple told they can't adopt due to their views on homosexuality.
March 4, 2011 at 8:52 am
(March 3, 2011 at 11:11 pm)corndog36 Wrote: I have 2 friends who are identical twin sisters, one is gay the other straight. I've done a lot of research on the issue and the bulk of the evidence suggests that homosexuality is environmental. Since gays are less likely to procreate, natural selection should have eliminated the trait long ago if it were genetic.
Not the case, firstly you can have the same genes as an identical twin but have different genetic expression, this is likely caused by different conditions/exposures in the womb, it is rare but not unheard of for twins to be exposed to different hormonal levels, if you are to have a set of genes that have the potential for homosexuality this hormonal difference can cause a difference in the expression of these genes, resulting in one being homosexual and the other heterosexual - This same gene will also be passed down through the straight and gay children laying in wait until such time as there is another similar hormonal imbalance causing different expression of the genes.
There are also plenty of closet homosexuals in heterosexual marriages, Ted Haggard being a well known example, that is another way for the genes to be passed down.
Natural selection wouldn't have much say in preventing this gene from being passed down as there is no inherent selection pressure, especially when it is a matter of a gene with multiple expression paths rather than a single gene being passed down - This is almost certainly the case, for example there is no correlation between gay parents and the chances of having a gay child.
It could well be the case that we all have the set of genes that are capable of producing homosexuality and they are the same genes related to normal sexuality but expressed differently.
There is also very little evidence for nurture playing a role in a child becoming homosexual, some studies suggest it is the case but even more suggest there is no correlation, a child living in a homosexually family is no more likely to be gay than one living in a fundamentalist community.
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