This is something I've been pondering myself recently, the leading scientific opinion is that jomosexuality is based on biology rather than being a choice, but I still wonder. I think Nature vs Nuture comes into play. Just wondering what others thoughts are.
"The only kind of homosexuality that even deserves a scientific investigation for possible genetic determination ..."
This statement is just wrong. We just don't know whether it is genetic, a combination of genetics and environment, purely environmental, or "just a preference". Until it becaomes more clear, a number of avenues should be persued, if only to rule some of them out. As a former physics researcher I think you make a number of erroneous statements about science research.
"but no scientific-minded person would expect them to be genetically determined "
That's one. Numerous reputable and well-regarded researchers have valid reasons for suspecting genetics as being at least partially involved.
Let's just say, for the sake of argument, that we discover a gay gene or genes. Then there will no doubt be some ethical questions arising from this. I would be willing to bet that many of the anti-abortion groups here would be torn between wanting to allow the abortion of "gay fetuses" and sticking with their current stance. Others would want to pre-select "straight embryos". Some might start using the knowledge to look for a "cure". All of these things would be wrong, in my view. However, just because reasearch results and discoveries can be misused doesn't necessarily mean the research shouldn't be done.
I am a former researcher myself and know exactly what criteria are used to start an investigation.
No one would start an investigation into whether homosexual preference is biological much less genetic, out of pure academic curiosity anymore than they would a preference for masturbation or celibacy.
Even if someone was curious, since homosexuality is not restricted to the human species, why would they pick a species for study where the definition itself is fuzzy and not directly verfiable while they could pick species like mice to perform controlled experiments that are readily verifiable by others?
Whatever the social consequences, I don't object to honest and academic investigations. What I was cautioning against was well-intentioned but dishonest and politically motivated investigations claiming to be scientific and whose only purpose is to justify a political agenda.
If you are not a position to separate what is politically motivated BS from what is actual scientific research and have to depend on the number and reputation of the scientists to believe one way or another, I am sorry. But I am quite capable of distinguishing one from another for myself and don't really need to depend on the number and reputation of scientists who favour one view or another. This genetically determined homosexuality is pure BS.
I eagerly look forward to your receiving the Nobel prize for medicine for your seminal paper "I assert that a genetic cause of homosexualityis BS" :-)
No has yet identified a 'gay gene'. So talking as if its existence is undisputed is jumping the gun.
First, there is no such thing as a "gay gene". At least, there isn't any specific thing we know of that could conclusively be called that and fit in with what we know about genes and how they work.
Second, gay individuals have always had the ability to procreate, in nature or otherwise. But evolution works in populations, not just individuals. Heritable traits can be passed down by other relatives. For example, gay men never need to procreate to have their genetics passed on when they have sisters who do so for them (gay uncle theory?). A great example of this is bees. Only the queen passes on her genes with the support of the hive.