And there is no question that homosexuality is replicated in every generation. It is part of Nature and has never threatened the continuation of mankind.
And? In every species, natures way is reproduction. If a body does not reproduce, it kills off its lineage. That is why, in nature, homosexuality has to be considered abnormal.
Mark
Nature is a complex and wondrous thing. Did you know that some species are
a-sexual? Did you know some could
change their gender? How about when animals
intentionally sterilize themselves due to over population?
Since Homosexuality exists in over a thousand animals species and has existed in the human animal since the beginning of recorded history, it's pretty safe to assume that we're supposed to be here. Rest easy, scientists have some theories.
The evolutionary puzzle of homosexuality
The genes that code for homosexuality do other things too
The allele - or group of genes - that sometimes codes for homosexual orientation may at other times have a strong reproductive benefit. This would compensate for gay people's lack of reproduction and ensure the continuation of the trait, as non-gay carriers of the gene pass it down.
Gay people were 'helpers in the nest'
Paul Vasey's research in Samoa has focused on a theory called kin selection or the "helper in the nest" hypothesis. The idea is that gay people compensate for their lack of children by promoting the reproductive fitness of brothers or sisters, contributing money or performing other uncle-like activities such as babysitting or tutoring. Some of the gay person's genetic code is shared with nieces and nephews and so, the theory goes, the genes which code for sexual orientation still get passed down.[...]
Gay people do have children
In the US,
around 37% of lesbian, gay, bisexual and transsexual people have a child, about 60% of which are biological. According to the Williams Institute, gay couples that have children have an average of two.
These figures may not be high enough to sustain genetic traits specific to this group, but the evolutionary biologist Jeremy Yoder
points out in a blog post that for much of modern history gay people haven't been living openly gay lives. Compelled by society to enter marriages and have children, their reproduction rates may have been higher than they are now.
It's not all in the DNA
Qazi Rahman says that alleles coding for same sex attraction only explain some of the variety in human sexuality. Other, naturally varying biological factors come into play, with about one in seven gay men, he says, owing their sexuality to the "big brother effect".
This has nothing to do with George Orwell, but describes the observation that boys with older brothers are significantly more likely to become gay - with every older brother the chance of homosexuality increases by about a third. No-one knows why this is, but one theory is that with each male pregnancy, a woman's body forms an immune reaction to proteins that have a role in the development of the male brain. Since this only comes into play after several siblings have been born - most of whom are heterosexual and go on to have children - this pre-natal quirk hasn't been selected away by evolution.