First: Lest anybody think I'm poking my snout into a category I should stay out of, and impersonally analyzing something that's none of my business because it doesn't affect me: I'm bisexual. I've got a bit of an excuse to be interested in such issues. Although it really doesn't affect my choosing to study and analyze whatever I see.
Second: No, this isn't a joke; it's actually a real hypothesis. Not strictly a hypothesis, because it is an explanation for something in the past and therefore, not testable. "Theory" is probably a better word, but it implies that it's more than a thought-study, which this isn't.
Anyway, behind cut tags because this is sort of long...
A Hypothesis for the Possible Evolutionary Devlopment of Homosexuality, and the Benefits Thereof, With Hypotheses for Present Behavior
This is going to be rather a dry read; bear with me here.
On the surface, homosexuality is apparently a counterevolutionary trait: it can be correctly observed that, in general, those with homosexual tendencies tend not to bear offspring. Due to the availibility of children for adoption, families are still had, but they are generally not geneline1.
Recent studies have shown that homosexuality is a genetically linked trait; counter to the propaganda of many religious groups, it is not a personal choice2. As homosexuals tend not to bear offspring, it would be expected for this trait to rapidly evolve out of the species once it is expressable, as it currently is due to slightly relaxed society inhibitions. This evolution, however, has not been observed, and one possible conclusion from this information is that it is evolved into the species as a recessive adaptive trait: one that lays dormant in the genetic code in the majority, if not the totality, of the population and expresses itself only when appropriate.
What possible evolutionary forces could have caused this trait to lock itself into the species?
One consideration is the incredibly sexual nature of humans. In short: humans are really freakin' horny. It has been shown in other studies and research that sex and sexuality are critical to human mental health, and excessive suppression- or even moderate suppression or denial- can and does lead to serious physical and mental health problems. By nature, reproduction is closely interwoven into the genetic code.
Even in the relatively hazardous environment of prehistoric times, regional overpopulation was a possible problem and therefore a potential evolutionary force. Communities of pre-humans could potentially gain a population to exceed the capabilities of the hunters, gatherers, and in later periods, farmers of the community, resulting in famine. This would result in the death of those who could not deal with reduced rations and were at the bottom of the social ladder.
Famine weakens every member of a community and splits a community as a whole; even those who are eating tend to be comprimized. A tribe without sufficient food will, as a whole, be more vulnerable to predators and hostile environement. Evolution, therefore, would have a strong bias towards those groups that can respond to overpopulation in some form that prevents the community from being weakened.
An obvious solution is reduced fertility. Having fewer children results in a smaller population, which can survive on less food. Fertility-related responses, while apparently the easiest to evolve into a population, have three difficulties:
1. Evolution's strong bias towards the horny results in a very horny population without enough of such genetic variance to significantly reduce fertility.
2. The results of reduced fertility are delayed a generation.
3. Due to the interweaving of sexuality into the genetic code, it would take a large quantity of point mutations to reduce fertility.
Even with those points in mind, fertility modification may have been evolution's responce to population crises. It would need to overcome those three problems, and breeding in conditions causing homosexual tendencies may have been a possible response. Homosexual tendencies in a population reduce children while solving problems one and three: horniness is still very present, but aimed at targets incapable of concieving, and requires fewer point mutations to create.
The second problem would be more complex and would require large amounts of evolution- but with a problem such as this, that evolution may have been accomplished in the relatively short period of human development. The solution is for the genes to "trigger" when signs of imminent overpopulation become apparent, instead of after it's too late.
The direct result of such evolution would be portions of a population being gay when the population is too large for the environment, with the second-level result of reduced conception rates in times of low resources, and the third-level result of greater general population survival due to an overall stronger community, and a fourth-level result of a greater chance to survive to pass on genetics, and a conclusive result of an evolving population.
Further effects would potentially be overall lower reproduction rates: some, or many, may find more satisfying partners in the same sex. Evolution, however, would be counter to this tendency: it's designed to increase numbers, not decrease them. Therefore, it would need to put a limit on its own creation- and this limit could be created in homophobic tendencies, so that fewer would act homosexual unless genetics force the issue.
Fast forward several epochs.
It's now a civilized world. Man has developed devices and methods that drastically increase his survival rate as a species. With surprisingly few threats to survival, and plentiful resources due to improved methods of gathering or growing, the population increases sharply and suddenly.
It's now 2003. The world is starting to fill up with humans. If the population continues increasing at its present rate, famine would certainly become far, far more widespread than it is currently, with no possible solution at the current human level of technology. As this is not a "visible" hazard, insufficient resarch is being done on the topic of resource increasing to sufficiently deflect this hazard.
So what genes would be kicking in? Imminent overpopulation is a definite and visible hazard- and at some level, everybody knows it. What we would be seeing is what we are seeing now: an increase in homosexuality. What we are most certainly seeing is an increase in its visibility and social acceptance- the former easily described by the latter, and the latter explainable by evolution to allow homosexual tendencies when overpopulation is imminent. The result will be fewer in the population actually reproducing, and a slowed growth rate, should my hypothesis be correct. As evolution so far has had to deal only with relatively temporary overpopulation, it is unlikely that our population problems will be solved; slowed, but most likely not solved.
If my hypothesis is accurate, what we would be seeing about now, with resources dwindling for a rapidly growing population:
1. Increasing homosexuality.
2. Extreme homophobia at the beginning, dissolving relatively rapidly.
3. Increased acceptance of homosexuality.
4. Reduced reproductive rates.
5. Perhaps reduced intrest in actually having children.
...guess what? This is what we're seeing.
There are, of course, many more explanations for Today; there are an infinite number. This is not to be taken any more seriously than your average crackpot crank wild theory.
It still might be worth discussion, however.
To further this, I have removed all comment restrictions from my LiveJournal. Enjoy the debate.
1. "Geneline" seems a more appropriate term than "bloodline." It refers, in this case, to genetically related offspring, as opposed to an adopted family. "Offspring" can be assumed to refer to "geneline;" "children" and "family" cannot be used with the same assumption.
2. Help from people less lazy than me to find a news story on this would be appreciated.