In certain sectors of society, any way of experiencing sexuality that goes beyond the so-called ‘cisheteronormativity’ is considered undesirable. Some religions affirm that it is an unnatural phenomenon and even describe it as aberrant.
The real world is very different from how these people present it. On the one hand, homosexuality, bisexuality or other forms of sexual expression other than cisheteronormativity occur naturally in the human species. That fact is enough to dismantle the idea that it is something unnatural. But, in addition, as has already been exposed in other Very Interesting articles, there are animals with homosexual behavior and with many other forms of sexual diversity in nature.
Natural or artificial? the false dichotomy
Of course, just because something is natural (or artificial) doesn’t automatically make it a good (or bad) thing . There are good and bad natural things for the human being, just as there are good and bad artificial things. That Manichaeism or false dichotomy in which it is assumed that everything natural is good —such as feces, volcanoes or botulinum toxin— and everything artificial is bad —such as vaccines, scientific research or tortillas with onions— is what they intend to appeal.
But, in any case, qualifying as ‘unnatural’ something that happens naturally in many animal species —of which the human being is one more— can only be done from a profound ignorance of nature, or from the worst of intentions.
The evolutionary question
Everything that arises in nature has a reason that justifies its presence. If there is an organ, a behavior or any other specific trait, it is that the species or the population obtains an advantage, or has had it throughout its evolutionary history.
With relative frequency, some groups argue that the homosexual organism does not transmit its genes to any offspring and the bisexual has a partial capacity, significantly less than the heterosexual organism. Based on these premises, they conclude that sexual diversity does not provide any evolutionary advantage.
As in the case of the natural or unnatural question, those who defend this point are wrong. The evolutionary process in general does not depend on the individual success of organisms, but on the success of their populations . And if one population is fitter than another—thanks to the traits of its members—then that population tends to have more offspring and better preserve its genes.
Benefiting family and species
It is true, and well documented, that homosexual animals—including humans—have fewer offspring than heterosexual ones. It is an intuitive conclusion, but well supported by data.
However, in many species —including some human cultures—, the homosexual organism provides a series of extra care for the offspring of its close relatives . In other words, it does not benefit the population by perpetuating its own genes, but it does help to perpetuate those of its brothers and sisters, thus providing evolutionary advantages to the population. It is a behavior similar to that of the worker ants, which although they are not reproducers, help to perpetuate the genes of their sisters and brothers in the colony that are, and that thanks to their efforts, they will be able to carry out their nuptial flight successfully. .
Another hypothesis that has been raised is directly related to genetics, in what is called sexual antagonism . And it is that, as has been observed in some studies, male homosexuality is associated with genes that increase the reproductive success of females; that is to say, that the mothers, sisters and aunts of the homosexual male tend to be more successful.
One more option being considered is related to social cohesion . Among social animals, homosexual individuals present a cohesive factor in society, which does not exist when the population lacks them. This makes populations with these individuals more robust, and generally more fit.
These hypotheses are not mutually exclusive, it may be that in a given species or population (human or not), several occur simultaneously.
With this scenario, of course, bisexuality has the much clearer advantage ; they are organisms that can adapt to one role or another, and even change from one to another several times throughout their lives, favoring the community indirectly, and also through their own offspring.
Homosexual and bisexual behaviors are not only completely natural and perfectly healthy , they have real evolutionary advantages. Ironically, the human being is the only species that presents individuals with an aversion towards homosexuality, and that homophobia certainly does not provide any evolutionary advantage .
References:
Bagemihl, B. 1999. Biological exuberance: animal homosexuality and natural diversity. St. Martin’s Press.
Bailey, N. W. et al. 2009. Same-sex sexual behavior and evolution. Trends in Ecology & Evolution, 24(8), 439-446. DOI: 10.1016/j.tree.2009.03.014
Fruth, B. et al. 2006. Social grease for females? Same-sex genital contacts in wild bonobos. En Homosexual behaviour in animals: An evolutionary perspective (pp. 294-315). Cambridge University Press.
MacFarlane, G. R. et al. 2007. Same-sex sexual behavior in birds: expression is related to social mating system and state of development at hatching.
Behavioral Ecology, 18(1), 21-33. DOI: 10.1093/beheco/arl065
Rahman, Q. et al. 2008. Maternal Inheritance and Familial Fecundity Factors in Male Homosexuality. Archives of Sexual Behavior, 37(6), 962-969. DOI: 10.1007/s10508-007-9191-2
