Originally published at crisis magazine
On February 5, three prominent biologists and presidents of major biological associations wrote a letter to President Trump and Congress opposing his January 2025 Executive Order 14168, titled “Defending Women from Gender Ideology Extremism and Restoring Biological Truth to the Federal Government.” The letter alleges that scientific evidence contradicts the binary view of sex by emphasizing the complexity of sex determination involving chromosomes, hormones, and anatomy, and highlighting variations that suggest sex and gender are not strictly binary traits.
What Does the Evidence Really Say?
The biologists’ perspective conflates biological sex with gender identity. Biological sex is determined by the type of gametes produced: males produce sperm, and females produce eggs. This dichotomy is consistent across sexually reproducing species, underscoring the binary basis of sex. This is noted in a response letter written by some eminent biologists, such as neo-atheists Jerry Coyne and Luana Maroja, and also backed by the British zoologist Richard Dawkins, which addresses the misconceptions about definitions about biological sex: “The universal biological definition of sex is gamete size.”
The letter challenging Trump’s executive order asserts that “sex and gender result from the interplay of genetics and environment,” conflating gender—a social construct—with biological sex. Even though the assertion that sex exists on a
