Evolution and Homosexuality

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Evolution and Homosexuality
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Musings on the Nature of Gender, Reproduction, and Sexuality

We all love and seek to be loved. This is universally evident in humans and in other species alike.

A life well lived includes intimate relationships, where we get to know others on a deeply emotional level. Many of these intimate relationships also become passionate relationships, where we get to know each other on a sexual level.

Who’s to say what these passionate relationships should look like? And who’s to say how we should feel about the passionate relationships in which others choose to participate?

In societies across the globe we, as Homo sapiens, have outlined what is culturally and socially acceptable from a sexuality perspective. Unfortunately, these outlines tend to leave some percentage of the population on the outside of our acceptable norms, looking in with loneliness and fear.

“I suppose that a lifetime spent hiding one’s erotic truth could have a cumulative renunciatory effect. Sexual shame is in itself a kind of death.”

Alison Bechdel

As beings who are cognizant of our own consciousness, we have the power to rationally decide which constructs to adopt or apply to our lives.

Does the construct we choose to adopt have to leave some percentage of our species on the outside looking in?

How Does Evolution Account for Homosexuality?

A while back, I had a conversation with a very dear friend of mine. We spoke philosophically about many subjects, as we often do, and our conversation eventually landed on the subject of homosexuality.

As I tend to apply my understanding of the Principles of Evolution to nearly every conversation in which I participate, my friend began to question me on the relationship between evolution and homosexuality.

Essentially what he was asking is — How could evolution allow for homosexuality, when the aim of evolution is to maximize the chances of procreation?

If homosexual individuals are not able to produce offspring together, then how could homosexual tendencies be explained through evolution? Wouldn’t evolution have stamped out the homosexual impulse long ago?

At the time of our conversation, I did not have a good response to offer my friend and, unfortunately, I wasn’t able to answer his questions satisfactorily, either for him or for myself.

With time, I’ve been able to read up on the subject of Homosexuality and to do a great deal of thinking about the nature of evolution and the human understanding of gender, reproduction, and sexuality.

What follows is my attempt to distill the information I’ve gathered and the thoughts they’ve elicited within me.

Variations in Reproduction

As an animal species, our sexual practices are more than a little strange. As far as I’m aware, we are the only species that intentionally cover our genitals from view, we are the only species to have sex in private, and we are one of the few species to have sex for pleasure.

The thing with sex and reproduction is that we tend to think our way is the “right” way, or at least the “normal” way. Yet, the innumerable examples found in nature, tell us that human sexual practices are anything but the standard.

As humans, we seem to be eternally reliant on norms. Anything outside the norm gets labeled, discredited, shamed, shunned, feared, and bullied.

“The world is so obsessed with defining sexuality for everyone and attaching labels to it. Any time any person openly leaves the sexual norm, their sexuality becomes, more often than not, the absolute defining characteristic of that person. It becomes the first thing people think about and often the first thing they mention. Every other part of that person all but disappears.”

Dan Pearce, Single Dad Laughing

The reality is that there is no one right way to do anything. Ever. Nature has found a whole host of methods for species and individuals to reproduce.

Here are some of these methods.

Sexual Reproduction

This is the form of reproduction we are most familiar with, as we do it ourselves. Yet, even sexual reproduction takes on multiple forms.

Allogamy: In allogamy, an ovum of one individual is fertilized by the spermatozoa of another individual. This can occur either internally, such as when the male penis is inserted into the female vaginal canal, or externally such as when male salmon release their sperm into a river in which the female salmon have also release their eggs.

Many species reproduce through allogamy. Dragonflies can often be seen entangled in sexual intercourse, as they zoom recklessly across the yard. Snakes become entangled in a venomous mess. Bonobos and dolphins hump each other to exhaustion.

Autogamy: In autogamy, a single individual provides both gametes used in the reproduction process. The most common example is that of hermaphrodite plants, which self-pollinate their own flowers.

This method of sexual reproduction may not sound as fun as internal allogamy, but it gets the job done.

Asexual Reproduction

With asexual reproduction, individuals create genetically similar or identical copies of themselves without the contribution of genetic material from another organism.

Bacteria reproduce asexually by splitting themselves into two identical or very similar individuals. Viruses highjack the cells of their host and use the material to make copies of themselves. Hydras ( a genus of fresh-water organisms) and yeast are able to reproduce asexually through a process known as budding, where a new organism develops from an outgrowth or bud due to cell division at one particular site.


For some species, only a single individual is needed to begin the process of reproduction. Parthenogenesis is a natural form of asexual reproduction in which growth and development of embryos occur without fertilization. For species that produce through parthenogenesis, the offspring are genetically identical to their parent (in this case a single mother).

Examples of species that reproduce through parthenogenesis include some plants, nematodes (roundworms), water fleas, some scorpions, aphids, some mites, some bees, some Phasmida (stick bugs), parasitic wasps, some fish, some amphibians, some reptiles, and some birds.

A Mixed Bag

Some species are believed to possess the ability to reproduce both sexually and asexually. These species include the hydras and yeasts mentioned above, as well as some jellyfish and some plants.

Variations in Sex

The idea of norms becomes even more disturbing when we consider an individual’s sex. We tend to classify Homo sapiens as either male or female because those are the two predominant outcomes that occur through our procreation process, but those aren’t the only options.

“Heterosexuality is not normal, it’s just common.”

Dorothy Parker

A side note — I do not want to misuse the terms sex and gender here. In the past these two terms have been used interchangeably, however, the modern scientific view of these two terms is more distinct. Sex typically refers to the biological differences in individuals (a penis vs. a vagina). Gender typically refers to the cultural differences or expectations in individuals (manly vs womanly).

Now, let’s take a look at some examples of biological diversity in sex.

Bilateral Gynandromorphs: A gynandromorph is an individual that contains both male and female body parts. Bilateral gynandromorphs display their male and female parts, right down the center of their bodies, with one side appearing male and the other appearing female.

Examples of bilateral gynandromorphs include moths and butterflies, birds, bees, lobsters, crabs, and reptiles. In each case, either the right or left side of the body will appear male or female based on the typical characteristics of the species sexes (color, size, shape, etc…) while the other side of the body will appear to be the other sex.

Hermaphrodites: For many species, individuals being born as hermaphrodites is actually the norm. A common example in nature is that of snails and slugs.

Each member of the genus Ariolimax (commonly known as banana slugs and found in the moist Redwood forests of the pacific Coast) are born with both male and female sexual reproduction organs. When two banana slugs mate, they actually perform sexual intercourse with all of their existing sex organs.

Male parts are inserted into female parts, and both individuals are impregnated. Pretty dope, huh?

Another example of hermaphrodites in nature is the genus Pogona (commonly known as Bearded Dragons). In some instances, male individuals will develop female reproductive organs, while still an embryo in the egg. When these individuals are born, they are still genetically male but are also able to breed with other males of the species. Scientists claim that these pregnant males will actually produce more offspring than their strictly female counterparts.

Could this be the direction evolution is taking us?

Single-Sex Species: For some species, there is no battle of the sexes, either because variant sexes never developed, or one sex must have won out.

An example of a single-sex species is the Procambarus fallax or marbled crayfish. Within this species, every individual is female and offspring are produced through parthenogenesis.

Another example of a single-sex species is the Aspidoscelis uniparens, or Whiptail lizard, found in New Mexico. These lizards also reproduce through Parthenogenesis, but after the new offspring are born their genetic code somehow changes. These changes provide the variation within the species that protects it from evolutionary catastrophe.

Multi-Sex Systems: Rather than taking the seemingly more simple route of narrowing a species down to a single sex, some species evolve to the point of having multiple sexes. In the case of Schizophyllum commun, a species of fungus, a verifiable 23,000 sexes exist simultaneously.

While this may sound complicated, it actually makes reproduction a snap. All the fungus has to do in order to reproduce is rub up against another individual of its species. There is no concern for the sex of the individual fungi’s partner.

Sex Changes

Another cognitive norm that we can throw out the window is the idea that sex is static. In nature, it can be anything but static. Many species of fish and amphibians change sexes when the situation calls for it. If the idea of individuals organically changing sexes in the wild sounds a bit strange to you, just remember what Dr. Malcolm taught us,

“Life finds a way”.

A common example of a species that changes sexes naturally in the wild is the anemonefish, a subfamily of Amphiprioninae commonly known as clownfish. In the case of clownfish, all members of the species are born male.

Then, when the need presents itself, male clownfish will change sexes and become female through a process known as sequential hermaphroditism.

A family of fish known as Labridae or more commonly wrasse, use the opposite approach to sex changes that clownfish employ. When the dominant male disappears from the group, a female fish will then grow male sexual organs and establish herself as the new dominant male.

Another species of fish known as Parrott fish are born as hermaphrodites and can later change to either sex based on the needs of the population.

I suppose that the message, as far as sex is concerned, is that there is no one right way to go about it.

Homosexuality in Other Animal Species

Another clear example of why we shouldn’t consider Homosexuality in humans as abnormal is the abundance of Homosexual activity found throughout the animal kingdom.

While the most prominent cases of Homosexual behavior can be found in social animals, Homosexual behavior has been observed in every major animal group.

Take that in for a second — every major animal group in every geography across the globe participates in Homosexuality.

A very popular example of Homosexual behavior in animals is sheep. According to research, 8% of all rams are strictly homosexual. Meaning that they never engage in Heterosexual intercourse, instead opting for a purely Homosexual existence.

From all that we’ve already covered, we can clearly see that sex, gender, and reproduction are not static institutions — despite our human institutions’ efforts to make them appear so.

The questions still remain — why? Why does evolution allow for (and seem to foster) the development of Homosexual individuals?

Principles of evolution


Variation is an essential component of evolution. Heritable, genetic differences can be found within the individuals of each species. These differences manifest themselves as both visible and invisible traits and create advantages or disadvantages for the individual.

From the perspective of a species, variation is preferred and necessary, as it provides a higher chance of survival for that species. Without variation in the gene pool, a species becomes vulnerable to environmental factors that may lead to extinction.

For this very simple reason alone, variations in sexual preference make sense from an evolutionary perspective.

“Homosexuality is neither a sin, nor an anomaly or a disease. It is an evolutionary variation.”

Abhijit Naskar

If it seems strange to you that variation should come in something as critical as reproduction, take a moment to consider that evolution must test every possible genetic variation.

If the genetic code did not allow for every possible trait to be tampered with, weaknesses would persist throughout a species.

Through this line of thinking, Homosexuality is an attempt to protect and ensure the ongoing success of our species. If this sounds crazy, consider the case of the Bearded Dragons, which I mentioned previously.

In the case of this species, they have evolved to a point where male individuals are able to reproduce with other male individuals.

Crazy but pretty cool.

The Absence of Design

A common belief among religious folks is that sex or gender is predetermined and that any desires that don’t fit that predestination are the result of temptation or unholy physical desires. In this sense, Homosexuality is a test of one’s faith, willpower, and obedience to diety. It’s a rejection of a divine order, design, and plan.

The problem with this type of thinking is that it leads to more questions and conundrums than it does answers. When one is able to let go of the proposition that all things are predetermined, the world suddenly becomes clear.

“Nobody is wired wrong, because there’s no wrong and right in the way we are.”

Hannah Hart

Evidence of evolution is all around us and provides us with an understanding of why things are as they are. Evolution cannot produce perfection, and unfortunately, reality does not provide us with an archetype for perfection, as the idea of perfection originates within our minds.

There is no right or correct sexual orientation based on design. If there were, the creator would have some very heated conversations coming in the next life.

Survival of the Good Enough

Another aspect to consider in the discussion of evolution and Homosexuality is the erroneousness of the term “survival of the fittest”. Many people have used this term to explain evolution, but unfortunately, it falls short time and time again. Billy Nye, yes the Science Guy, has coined a phrase that is probably more appropriate,

Survival of the good enough.

Simply because an individual has a trait or set of traits that are not as advantageous as another individual, does not necessarily mean that the individual will not pass on its genes.

Almost everyone can name at least one person in their life, who identifies as Homosexual (or at least not Heterosexual) and has still produced a child or multiple children.

Just because you don’t have all of the most “advantageous” characteristics, does not mean that you will not survive and will not reproduce.


In the past, I have been guilty of inaccurately characterizing and stereotyping people who do not identify as Heterosexual. I’d like to think that this was due to ignorance, and I hope that in my case you can apply Hanlon’s razor,

Never attribute to malice that which is adequately explained by stupidity.

Based on the evidence I’ve laid out here, I hope that readers can walk away with a more clear picture of the role Homosexuality plays in nature. Because, after all, it is clearly natural.

Some things we can do in light of this information is to do our best not to define anyone by their sexual preference. We don’t need to make people feel inferior or out-of-place because of their orientation. We don’t need to limit their right or their opportunities.

We need to see them as humans and embrace them as critical members of our species. After all, they may be evolutions way of making sure Homo sapiens continues on into the future.

“The enemy is not individuals, churches, ‘ex-gay’ organisations or political parties; the enemy is ignorance. Change is created by focusing our energies on overcoming the latter instead of attacking the former.”

Anthony Venn-Brown


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