Not the Big picture, but you do fall for the picture painted in front of you.
Doc, to be honest, in today's world, genetic studies have advanced so much. It is impossible that the presence of a gene is missed/unverified.
To tell you the truth, the proposition of a male homosexual gene was retracted because they made it up, but the linkage they tried to put forth under evolutionary aspects (and the one you also quoted for the hunter's tribe) could not explain the Lesbian phenomenon. Do you also have an explanation of Lesbianism in a hunter's society and in evolutionary context?
In such metaphysical contexts, the meaning of the words "May/Might" means that the study is inconclusive and the results cannot be generalized.
What is evident here is that they are trying to find a reason to rationalize homosexuality, but they are unable to find one yet. However, this is conclusive that there is no "Gay Gene" found. There is no conclusive study to support the hypothesis that homosexuality is prenatal.
In fact... NO. First of all, you cannot eliminate the social and psychological factors in an "in vivo" study. That is why, in medical/clinical research, it is not taken as reliable as an in vitro study. Secondly, there is a phenomenon known as "Replication Fallacy" and "Conditional Probability Fallacy" which has plagued much of the research nowadays. It produces biased results, by biased mindsets. It is more common in "in vivo" studies.
Well, in an evidence based analysis/discussion/debate/syllogism, it does not matter where you live. We are talking about the hardcore facts here, revealed by the analysis of occidental research and findings.
However to give you a pretext, I have lived in both the western countries and in Muslim countries as well. I have also seen people in West, who abhor the idea of homosexuality. Moreover, I have also seen gay and trans etc. in Muslim countries. So your disposition that I have a natural tendency to be anti-gay is based on the societal influences is totally false.
I am very objective about the topic here. Give me a solid evidence that a gay gene exists and I am not haughty enough to negate you just because I personally do not think that there is a genetic link to it. However, I expect the same in reciprocation. Conversely, if you are predisposed with the notion of defending homosexuality because in your society it is accepted as such, then it is not a reasoned debate, rather a partial argument.
To be an atheist, a person needs to be very objective about the facts and reasoning. Not only should he be able to question the religious thought, he should also be able to take things coming up from "commercial and sponsored researches" with a pinch of salt.