Ovum surrounded by sperms

Why Sex Is Binary

The ideological assault on certain areas of science has recently been unbelievable. While everybody heard of creationists or Flat Earthers (a.k.a., “Flerfers”), a recent decade has seen a rise in the sex denialist movement. This group of hysterical and undereducated brats represents a part of Social Justice (a.k.a. “woke”) ideology (note the name is capitalized).

Philosophically, they are rooted in postmodernism and keep denigrating the scientific method as being one of many “ways of knowing”. Science, according to Social Justice Warriors (SJWs), is fundamentally flawed by its main actors being white Western heterosexual males. Sounds sexist and racist? Because it is. The primary focus of an SJW is not being factually correct but rather being morally correct, as outlined by several influential figures in their group. What is moral then? It is standing by the side of the “oppressed and marginalized” as pointed out by the ideologues. Generally, anyone non-white, non-heterosexual, non-thin, or not able-bodied qualifies. The reason why the sex binary is under attack is primarily a wish to empower the “gender nonconforming” groups.

Let’s move on to the main topic. The first thing to note is that not all sexually reproducing organisms have sexes. For instance, protists or fungi don’t have sexes, but they do have mating types and their numbers can be from two (baker’s yeast) to thousands like Basidiomycota. The common denominator here is that one cannot determine the mating type from morphological traits.

However, most multicellular organisms use special cells for sexual reproduction. Those sex cells differ morphologically (it is called anisogamy) and we only know two kinds of them: sperm and ova. Sperms are small, often mobile male gametes and ova are large immobile female gametes. This is basically the reason why there are only two sexes since sex is defined by a gamete type.

What about the rest of the complexity? It is secondary; gamete type is the common denominator for all anisogamous organisms: from a fern, through any tree, insect, or toad to us, humans.

It is crucial to be able to distinguish how sex is defined, how it’s determined, and how it’s recognized. We’ve already mentioned the definition. There are several determination systems; most of them rely on chromosomal sets (XX and XY in humans) but there are also ones dependent on environmental factors. We recognize that a particular individual is of a particular sex by using sexual characteristics. Note that to know which characteristics can be used to tell apart two sexes, you need to know the sex of an individual first, which is possible thanks to… the definition.

I will summarize the attacks on sex binary that I know in a FAQ form below.

But some fish can change sex during their life which makes sex a trait on a spectrum.
Those are sequential hermaphrodites and since they only produce two gamete types, there are still two sexes.

All traits are on a spectrum, therefore, sex is a spectrum.
Can I have a square root of pi belly buttons? No! Not all traits are on a spectrum. Sex is a categorical variable.

Gynandromorphs/intersex individuals prove sex is on a spectrum.
Those are rare developmental anomalies in dioecious species and do not produce any third gamete type. Most human intersex individuals are sterile. Therefore sex is still binary.

Sex definition should be species-specific and include sexual characteristics!
It cannot be. Imagine you discover a previously unknown species in a jungle. You know nothing about its sexual characteristics and hence they cannot be included in the definition. They are dependent on a definition that is one for all and sufficient to capture the essence of the entire complexity related to sexual reproduction.

I’m glad you’ve reached the end. I hope you can see how nonsensical the attacks on sex binary are. The Social Justice critique of the sex binary is a mere and silly nitpicking. Another fact that triggers a SJW is immutability of sex in humans but this is a topic for another write-up.

If you’d like to learn even more on the ideological attacks on sex binary, please check Reality’s Last Stand published by evolutionary biologist Dr. Colin Wright.