Are we born to an evolutionary purpose?

As has been pointed out ( and documented) in several previous threads, homosexual and bisexual behavior is common throughout the animal kingdom. Its purpose is to establish and fortify relations amongst the individuals in social groups. This can be almost as important to the survival of a gregarious group (and its genome) as is reproduction. We humans shake hands, hug, and kiss members of both sexes to define our relationships. It would be setting an arbitrary limit to exclude sexual release from this repertoire of behaviors. My mother could put an end to any dispute, no matter how heated, with a "Come. We'll sit. We'll eat. We'll talk." (No, she didn't include "We'll screw", and yes, she was a Democrat.)"Survival of the fittest" does not just apply to individuals. It applies to groups, herds, tribe, species, and even to the genome mix of entire ecosystems. In fact, it only applies to an individual to the extent that that individuals survival supports the survival of the group and species, and thus might entail that individual's sacrificing his reproductive success if doing so enhances the groups viability (which explains sacrificial altruism such as jumping onto the live hand-grenade to save your buddies).There is yet another way in which homosexuality promotes the groups survivability: According to the bible, god says "Be fruitful and multiply". According to Darwin, evolution says "Be fruitful and multiply, but not to the extent that you exhaust your resources." It has been found that a great many species have techniques to insure that they do not excessively reproduce and exhaust their resources: Some reptiles change their sex ratios depending on their environment, producing more females (who can then produce more offspring) and fewer males when food is abundant, and visa versa when food is scarce; some species advance or delay the onset of fecundity depending on available resources. The option for our the human genome to 'turn on' the homosexual behavior in a subset of its phenotype when faced with high population density can act as an effective modulator of population growth.