The science is settled - homosexual lifestyle is a CHOSEN lifestyle. There is NO homo gene.
They search, with the persistence of Sauron looking for The Ring (sorry for LOR reference!) for a genetic tag for homosexuality.
They search, so insistently and desperately, because that will render them the privilege to say that homosexuality, instead of being a sexual peccadillo, is the same as sex or pigmentation in the skin.
Eventually, they will simply make it up, and it will become “settled science”.