I don't think it suggests that at all. This extract from a New Scientist articleoffers several plausible reasons why genetically determined homosexuality could have an evolutionary advantage.
Among animals, homosexual behaviour is usually non-exclusive. For instance, in some populations of Japanese macaques, females prefer female sexual partners to male ones but still mate with males - they are bisexual, in other words.It has also been suggested that homosexuality boosts individuals' reproductive success, albeit indirectly. For instance, same-sex partners might have a better chance of rising to the top of social hierarchies and getting access to the opposite sex. In some gull species, homosexual partnerships might be a response to a shortage of males - rather than have no offspring at all, some female pairs raise offspring together after mating with a male from a normal male-female pair.Another possibility is that homosexuality evolves and persists because it benefits groups or relatives, rather than individuals. In bonobos, homosexual behaviour might have benefits at a group level by promoting social cohesion. One study in Samoa found gay men devote more time to their nieces and nephews, suggesting it might be an example of kin selection (promoting your own genes in the bodies of others).
My wife of 17 years and I are definitely heterosexual, but have no children (we married for the first time each really late in life). My wife in particular, and I to a much lesser extent, have helped raise 5 nieces and nephews. One could argue that this form of surrogate parenting by an aunt and/or uncle helps to promote the familial gene pool, thereby being beneficial without actually contributing to the progeny. You could argue the same for a gay aunt or uncle.
Edited by fahrquad, 03 October 2016 - 01:44 AM.