At a time when backlash against diverse gender and sexual identities is intensifying across the world, it is worth remembering that some of the earliest conceptualisations of gender diversity pre-date modern science by millennia.

Clay tablets inscribed in cuneiform from Sumerian mythology, dating to approximately 2000-1600 BCE, tell the story of the goddess Inanna's descent into the underworld in one of the world's oldest surviving literary texts, eponymously titled 'Inanna's Descent'. In this myth, the god Enki creates two beings, the kurgarra and the galatur, who exist beyond the male-female binary to revive and rescue Inanna after she is killed by the Queen of the Underworld.

Similarly, ancient Indian texts also acknowledged sexual and gender diversity long before modern scientific frameworks emerged to even categorise them. The Kama Sutra, written around the fourth century CE, classifies humans into men, women, and those of a "third nature," and discusses same-sex desire without moral condemnation or pathology. Queer identities and practices, therefore, are not modern inventions. Rather, they have deep historical and cultural roots that long pre-date contemporary debates.

Turn to the animal kingdom

Furthermore, if we look beyond the human world to the animal kingdom, we find striking examples that challenge normative assumptions about heterosexuality, binary sex, and fixed gender roles. Same-sex behaviour, sequential and simultaneous sex change, asexual reproduction, and non-binary reproductive strategies are widespread across species. Such phenomena have long vexed biologists and ecologists, prompting important questions such as: how much diversity actually exists in nature? How does it develop over an organism's life course? And what explains its persistence across time?

These questions lie at the heart of American evolutionary biologist Joan Roughgarden's groundbreaking 2004 book, 'Evolution's Rainbow'. Both celebrated and contested upon its release, the book advances a provocative claim: that neo-Darwinian sexual selection theory - long used to explain mating behaviour, competition, and reproductive roles among species - fails to account for the extraordinary diversity of sex, gender, and social organisation found in nature.

And yet, more than two decades later, the public continues to debate whether homosexuality and transgender identities are "natural" and can be "cured." The persistence of these questions is itself revealing. When history and biology alike
demonstrate that sexual and gender diversity are recurring features of life, these debates cease to be about nature at all. They are instead about people's anxieties around difference and their desire to preserve rigid moral hierarchies.

I came to understand this multiplicity of life more viscerally through my own recent encounter with the natural world. I was on a visit to the Andamans for a scuba diving expedition to celebrate my birthday. While I expected technical challenges with the diving equipment underwater, what I did not expect was the sheer diversity I eventually witnessed.

As I descended into the ocean, I encountered clownfish weaving through sea anemones, sea cucumbers camouflaged against the ocean floor, lionfish displaying their striking, venomous spines, and sea stars, some as large as dinner plates, scattered across the reef.

It was only later, when I began reading more about these species that their biological stories slowly came to strike me as powerfully as their beauty.