On 16 April 2025, the Supreme Court made a landmark ruling about gender.

 

What the judges said – and the full 88-page document is accessible on the internet – is that in relation to the Equalities Act 2010, the terms ‘sex’, ‘man’ and ‘woman’ refer to biological sex and nothing else – not gender reassignment, not self-identification, nothing to do with pronouns, with names, or with how we choose to present ourselves to others.

 

Put simply, this is what the judges ruled. Women are biological women. Men are biological men. Trans women are biological men. Trans men are biological women. Non-binary people don’t exist in law. Intersex people are whatever sex has been registered on their birth certificate, regardless of chromosomes, genitals, or how they feel inside.

 

What a total mess.

 

I don’t entirely blame the judges. It must have felt impossible. They knew that their judgement would be hailed as a victory for the transphobes. They tried to warn against using their ruling as a political football. They explicitly stated that trans people are still protected in law, that trans people still have rights.

 

But they couldn’t control it. They couldn’t stop the vitriol and the hate.

 

The problem that the judges had is the same problem that we all have. The legal system does not reflect the reality of gender.

 

I blame Darwin.

 

That might sound a bit harsh, but Darwin has got a lot to answer for.

 

Darwin has contributed immensely to our understanding of the natural world. His theories of evolution, natural selection, and sexual selection, written about 150 years ago, were groundbreaking. But in arguing that sex is only for the purpose of procreation, he implied that only heterosexuality can be ‘natural’. In positioning males as active, aggressive and intellectually superior, and females as passive, weaker and morally superior, he bolstered concepts of sexual essentialism. And – this is where we get back to the Supreme Court ruling – he cemented the notion that sex is binary.

 

The field of Queer Ecology has helped us to see that the natural world is extremely diverse. It is not simple, clear-cut, or binary. These ecologists are not trying to prove a point. They are using a different lens, one with a much wider angle, and they are saying what they see.

 

Sex-fluid fishes such as parrotfish and clownfish. Intersex animals like the cane toad. Dolphins that pair up as young males and stay together for the rest of their lives. Hyena groups that are female dominated, and where aggressive female hyenas seek out submissive males. Non-binary birds such as the white-throated sparrow. Swans and penguins with examples of males taking the parenting roles. On and on and on.

 

Don’t get me started on fungi. And trees.

 

The fact is that nature is not binary.

 

As humans, we frequently look to the natural world to justify our attitudes and opinions. Humans are animals. If it doesn’t happen in the natural world, then it’s not natural. Surely then, if there is so much evidence of diversity within the natural world, then being trans or intersex or non-binary as a human being is natural. And if so, then why are these ways of being denigrated and mocked and diminished? It makes no sense.

 

You might ask why I blame Darwin, as Darwin could only use the data that was available to him at the time. You may think that I am being unfair.

 

I’ll tell you why.

 

Darwin knew all this. Or at least, he knew more than he let on.

 

Darwin knew about the queer, the unconventional, and the non-conforming. He had evidence that contradicted his theory of sexual selection, but he chose to dismiss these as ‘anomalies’ and ‘curiosities’. According to Brooks (2021):

 

Through the 19th century, gender and sexual transgressions were subject to a plethora of relentlessly queerphobic theological, legal and cultural proscriptions, prompting scientists such as Charles Darwin to repress such issues in their writings and in their lives.

 

In other words, the existence of gender and sexual diversity was an inconvenient truth to Darwin, and he hushed it up. He hid it because it might confuse or offend his audience. He spun a tale that fitted his context, and it set off a train that became hard to re-route. Others took hold of his theories, and confirmation bias did the rest.

 

That’s why I blame Darwin.

 

I think that most people now know the truth. We know that sex is not binary, and that a plethora of gender identities is natural. We know, and yet we are living in a world which was designed in a different way.

 

It’s time to tell the truth.

 

Sex is not binary.

 

I know that.

 

Darwin knew that.

 

And you do too.

 

Let’s tell the truth.

 

 

 

 

Check out:

 

Brooks, R. (2021) Darwin’s closet: the queer sides of The descent of man (1871). Zoological Journal of the Linnean Society, Volume 191, Issue 2, February 2021, Pages 323–346. Available at: https://doi.org/10.1093/zoolinnean/zlaa175

Cook, L. (2022) Bitch: a revolutionary guide to sex, evolution and the female animal. London: Penguin.

 

Davies, J.L. (2024) A Little Gay Natural History. London: Natural History Museum.

 

Fuentes, A. (2022) Biological Science Rejects the Sex Binary, and That’s Good for Humanity. Available at: https://www.sapiens.org/biology/biological-science-rejects-the-sex-binary-and-thats-good-for-humanity/ [Accessed 05/06/25]

 

Mortimer-Sandilands, C. & Erickson, B. (Eds) (2020) Queer Ecologies. Indiana: Indiana University Press.