The exchange of letters to the tri-Societies continues; they largely concede our points

On March 2, 125 scientists and people affiliated with biology (from 18 countries) signed a letter to the presidents of the Society for the Study of Evolution (SSE), the American Society of Naturalists (ASN), and the Society of Systematic Biologists (SSB) See my post about this here.

Our letter and signatures, resulting largely from the effort of Luana Maroja of Williams College, was written to object to the three societies’ previously published claim that biological sex in all species (not just humans) was some sort of multidimensional social construct that was, above all, NOT binary. Here’s one paragraph from their letter, dated February 5, 2025 and addressed to President Trump and “Members of the U.S. Congress.”

Scientific consensus defines sex in humans as a biological construct that relies on a combination of chromosomes, hormonal balances, and the resulting expression of gonads, external genitalia and secondary sex characteristics. There is variation in all these biological attributes that make up sex. Accordingly, sex (and gendered expression) is not a binary trait. While some aspects of sex are bimodal, variation along the continuum of male to female is well documented in humans through hundreds of scientific articles. Such variation is observed at both the genetic level and at the individual level (including hormone levels, secondary sexual characteristics, as well as genital morphology). Beyond the incorrect claim that science backs up a simple binary definition of sex, the lived experience of people clearly demonstrates that the genetic composition at conception does not define one’s identity. Rather, sex and gender result from the interplay of genetics and environment. Such diversity is a hallmark of biological species, including humans.

I can’t resist pointing out that the “lived identity” part has nothing to do with biological sex, but shows more than anything the ideological purposes of this letter.

Although these views were presented as a “scientific consensus”, the societies did not poll their members. Rather, I gather that they consulted their executive boards and decided that this was a good way to signal their virtue—even if involved distorting biology.  Their “multidimensional, multivariate” concept of sex, which incorporates information from a number of disparate traits, is in sharp contrast with what most biologists see as the definition of sex: a binary trait in all animals and plants that is based solely on whether they have the reproductive apparatus to produce large versus small gametes.  As Richard Dawkins has explained, the latter gamete-based “Universal Biological Definition” (UBD) of sex has the advantage that, yes, it’s universal (every plant and animal species has only two types of gametes), and it’s also explanatory, essential for understanding stuff like natural selection and sexual dimorphism. The multidimensional definition is neither universal nor explanatory.

The Tri-Societies “definition”—which isn’t really a definition—gives us no way to answer the two questions, “Well, how do you tell what sex a person/animal/plant really is?” and “How many sexes are there, then?” It’s a useless construct foisted on the public to show solidarity with those people who don’t identify with one of the two biological sexes. (I repeat again that it’s a description of nature, not a a prescription about how people should be treated.) But we felt that such a letter needed to be sent to show that by no means do all biologists agree on a multivariate definite of sex.

Our first letter (identical, but with only 23 signatures) was never answered, but this time we asked for a response and got one, signed by all three Presidents.  I can’t reprint it because we didn’t ask for permission, but some of its gist is in the response below from Luana. I will say that they admitted that they think they’re in close agreement with us (I am not so sure!), that their letter wasn’t properly phrased, that some of our differences come from different semantic interpretations of words like “binary” and “continuum”(nope), and that they didn’t send the letter anyway because a federal judge changed the Executive Order on sex (this didn’t affect our criticisms). At any rate, the tri-Societies letter is on hold because the organizations are now concerned with more serious threats from the Trump Administration, like science funding.

While I can’t reveal all the points they made, I can say that I see this largely as a victory for reason, as although the letter is still up at the link (they really should remove it and inform the members of the Societies), it wasn’t ever sent and they admit that it has several deficiencies. However, since they do admit those deficiencies, they really should take the letter down because it misrepresents biological reality as well the views of many–perhaps most–evolutionists. (You can also find the letter archived here).

At any rate, the Societies’ letter was sent to all 125 signers, some of whom read this website and are able to comment on the response. In the meantime, yesterday Luana sent the letter below to the Societies (quoted with permission).  Given that the Societies admit the letter was misleading and yet it’s still on the internet representing what is said to be a “scientific consensus” and not even giving a definition of biological sex, the proper thing to do would involve either taking it down or writing something newer based on a poll of the Societies’ members.

Luana’s letter:

Dear Dan, Jessica and Carol,

Thank you for your response.  We are pleased to hear that the letter has not yet been sent . Is the letter going to be removed from the website and members notified of the change and any future changes?

I am unclear what you mean by “Subsequently a federal judge decided against the Executive Order we were commenting on, and the wording of that EO then changed, rendering our original letter moot.”  I am not aware of such change – the EO is still in place (here). What are you referring to?

Furthermore, subsequent to the Executive Order 14168, the HHS has released a guidance (here) to the U.S. government, external partners, and the public to expand on the sex-based definitions. The HHS guidance changed the definition related to “producing gametes” (at conception) to sex “characterized by a reproductive system with the biological function of producing” eggs (ova) or sperm.

We hope we can indeed find common ground,

Best,
Luana

I end by saying that scientific societies need not be “institutionally neutral” when they are dealing with issues that affect the mission of the societies, as the definition of sex surely does. But what’s not okay is for the societies to distort “scientific consensus” in the interest of ideology. I have no idea if the Presidents of these societies really believe what they said (as Dawkins has pointed out, all three Presidents use a binary notion of sex in their own biological work), but something is deeply wrong when you use one notion of sex in your own science and yet deny that notion when you’re telling politicians what scientists “really believe.”