How does homosexuality work within an evolutionary framework? Natural selection insists that organisms produc?

Maybe if there were no gay individuals in any species, then the struggle for mating rights would destroy the population. It could be that a small fraction of the population is gay, so that the pressure during the mating season is less, leading to a higher probability of  birth and survival of young ones.

Homosexuality is not fully understood and it is unkown whether it is genetically controlled or determined by environmental factors. If this is the case, then Natural Selection would not apply to homosexuality as natural selection acts on narrowing down geneotypes which produce advantageous phenotypes (characteristics).
However, if homosexuality was genetically controlled then it would eventually be driven out of the gene pool (unless gay people are having kids!).

Natural selection is not as you may think it is...and in fact you are describing an individuals fitness, which may be defined as 'the number of offspring one has, in relation to the population'.

hope this clears up your issue.

The same way altruism is explained, kin selection.


And homosexuals don't NEVER have kids, btw
Homosexuality is the preference of ones own sex as sexual partners. I also have a sexual preference, super models. I can say with definite certainty that I've only rarely fulfilled my preference...

>"Natural selection insists that organisms produce the most possible offspring in order for the species to survive and to maintain itself. "

Actually, no.   First, natural selection does not "insist" this (look at bees or ants for a trivial example ... the majority of individuals are actually sterile, or never reproduce at all).  

Second, kin selection explains how individuals benefit from contributing to the survival of other indviduals' offspring.

Third, group selection is an important concept in any social species (like most primates).   Any traits in an individual that contribute to the long-term survival of the *group*, will tend to propagate in the species.  To make a simplistic illustration, the same traits that lead to male bonding and cooperation necessary to make an effective hunting party (or a football team) may also lead, in extremes, to attraction to other males.  Or traits that lead to child-nurturing instincts may also, when coupled with other instincts, lead to characteristics commonly associated with homosexuality.

Fourth, natural selection only acts on genetics.  Homosexuality appears to be at least partly genetic, as a *predisposition* to be attracted to one's own sex, but there are probably a lot of environmental contributors as well.

Fifth, the claim that homosexuality is at least in part genetic, does not mean that it is a single genetic "on-off" switch, but a complex combination of *many* genetic traits.   Each of these genetic traits, by itself, may lead to increased reproduction and nurturing of offspring, but in certain combinations may produce the predisposition to homosexuality.

Sixth, homosexuals can reproduce just fine, and can have just as strong an urge to reproduce and raise children as heterosexuals.  It's just a preference for a certain kind of sexual partner.  And from a behavioral, instinctual point of view, sex is not necessarily tied to reproduction ... i.e. heterosexuals don't have sex only with the goal of reproduction.   E.g. as a heterosexual, I am attracted to tall brunettes and short redhead women ... but that is quite independent of whether I have a desire to have children.


In short, genetics, homosexuality, and natural selection as it applies to an extremely social species, are all *far* too complicated to boil down to a simple statement about reproduction.

There are two assumptions that are implied in your question that are wrong.

1. You do not distinguish between "being homosexual" and homosexual behavior. One is social category, the other is a biological impulse.
2. That each individual in a population must reproduce at high rates.

Addressing these assumptions shows you how homosexuality does not defy evolutionary explanation.

First, you are partly right in that "being homosexual" is not evolutionarily probable. If we take principles of natural selection seriously, any trait that causes an individual to be exclusively attracted to the same sex would not subsist within a population for more than a generation since that individual would effectively be rendered sterile. So, it is not probable that someone is "born" with the exclusive sexual attraction to the same sex. This means that the "homosexual identity" that suggests that people find the opposite sex completely sexually repulsive is most likely a social construct and a result of a person's social experience and desires. (note: this does not make it a choice)

That said, attraction to the same sex and the desire to have sex with the same sex does have some selective benefits. For one, sex is a great way to solidify social bonds and establish dominance hierarchies. This allows for individuals/groups to migrate from their place of birth (which decreases inbreeding depression) and be integrated into other social groups where the dominant male or female (or many members of the group) establishes an emotional bond with new members through sex. This also offsets the need to be related to the people you care for (kin selection).

Finally, although it is improbable that an individual never desires the opposite sex in the natural world, it is not necessary or possible for each individual to maximize their reproduction since there are a limited number of eggs that can be fertilized each mating season. So, individuals may prefer the same sex and mate less often with the opposite and still have their genes represented in the next generation. "Being Homosexual" could also be a mating tactic where individuals with this trait socialize with female members and, while dominant males participate in energetically costly male-male competition or elaborate presentations for females, "homosexual" individual sneak sex with females without much hassle as they are not understood as threats by dominant males (this is called female mimicry).