Category: sex

Evolution meetings include an ideologically-based symposium on “teaching sex and gender”. It’s a spectrum, Jake!

June 20, 2025 • 11:00 am

A while back, the Presidents of the Society for the Study of Evolution (SSE), the American Society of Naturalists (ASN) and the Society of Systematic Biologists (SSB) posted this letter on the SSE website (click title to see archived version):

The letter was a response to Trump’s Executive order on sex, which gave the biological definition of sex: a binary based on the physiological apparatus for producing gametes of different size, of which there are two forms.  This is how the “Tri-Societies Letter” (henceforth “TSL”) started:

As scientists, we write to express our concerns about the Executive Order “Defending Women From Gender Ideology Extremism And Restoring Biological Truth To The Federal Government”. That Order states first, that “there are two sexes…[which] are not changeable”. The Order goes on to state that sex is determined at conception and is based on the size of the gamete that the resulting individual will produce. These statements are contradicted by extensive scientific evidence.

The TSL, posted on the SSE webpage, asserts that sex is a multivariate trait, is not binary but a spectrum, and that this spectrum occurs in all biological species. It adds this (bolding is mine):

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.

Note that it gives no way to determine whether an organism, including a human, is male or female! And how many sexes are there? This gives us no clue.

The letter went on to imply that all the members of the society, or at least nearly all of them, agreed with the Presidents’ views in the TSL:

Our three scientific societies represent over 3500 scientists, many of whom are experts on the variability that is found in sexual expression throughout the plant and animal kingdoms. More information explaining why sex lies along a continuum can be found here. If you wish to speak to one of our scientists, please contact any of the societies listed below.

It turned out that this was a distortion: the Societies had never polled their membership to see how many people agreed with their letter.

The result was considerable pushback against the TSL from scientists, 125 of whom wrote a letter to the Societies saying they didn’t agree with the TSL’s characterization of sex. Luana Maroja was the driving force behind this pushback, and the letter included this (I signed it, of course):

However, we do not see sex as a “construct” and we do not see other mentioned human-specific characteristics, such as “lived experiences” or “[phenotypic] variation along the continuum of male to female”, as having anything to do with the biological definition of sex. While we humans might be unique in having gender identities and certain types of sexual dimorphism, sex applies to us just as it applies to dragonflies, butterflies, or fish – there is no human exceptionalism.   Yes, there are developmental pathologies that cause sterility and there are variations in phenotypic traits related to sexual dimorphism. However, the existence of this variation does not make sex any less binary or more complex, because what defines sex is not a combination of chromosomes or hormonal balances or external genitalia and secondary sex characteristics. The universal biological definition of sex is gamete size.

You can see my other posts about this kerfuffle here.

The response from the Societies can’t be posted as we were refused permission to do so, but I characterized it this way:

. . . . 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 [we later did but were refused], but some of its gist is in the response below from Luana [Maroja]. 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.

The upshot was that the Societies eventually decided to remove the letter from the SSE website. What remains on the the original page is this, “This letter was originally posted on February 5th. A revised version is in progress and will be posted shortly.”

We are still waiting. I’m betting that no revision will ever appear. And it shouldn’t, for it’s not good for the premier evolution societies to pretend that biologists see sex as a spectrum.

What I’m leading up to is that, at the SSE’s annual conference taking place this month, the Society is sponsoring a three-hour symposium with four lecturers, a symposium that seems designed to reiterate the premises of the now-vanished letter. You can see the summary of this symposium by clicking on the link below to see synopses of the four lectures; then click on the bottom symposium, which looks like this:

If you go through the written summaries of the talks, you will see two themes reiterated:

1.) Biological sex is not binary but multifaceted, a “complex suite of traits across multiple organizational levels”.  No definition of biological sex appears to be given.

2.) Teaching that sex is binary harms those people who feel they’re not part of the binary, presumably nonbinary people, genderfluid people, some trans people, and the like. An important goal of teaching about sex and gender is to avoid harming people, and this form of teaching must be designed to avoid that harm.

The first point simply reiterates what was in the now-disappeared letter.  It makes the argument that many “progressive” biologists make: sex involves a combination of different traits.  This of course neglects the universality of the gametic definition, for no other definition holds for all animals and vascular plants. That’s why the definition (really a post facto observation) is used. In fact, many of those who hold to the “multifactoral” definition never even give a definition of sex, so I don’t know how they can tell that, say, a rabbit is male or female.

The second point turns biology teaching into a form of social engineering or propaganda: we must teach about sex in a way that does not harm people (i.e., offend them). I see this as distortion of biological truth in the interests of social justice, something that Luana and I discussed in our paper “The Ideological Subversion of Biology.” In fact, of course, teaching that biological sex is binary should not make anybody feel worthless or demeaned, for the dignity and rights of people depend not on biology but on morality, which is a social construct.  I have made this point endlessly and won’t repeat it here; see the end of the paper linked just above.

Some quotes from the summary and the abstracts:

Symposium summary at the beginning:

This symposium will explore the current science behind sex and gender, explore how educators can move their instruction beyond simple binary XX/XY paradigms, and provide educational materials for teaching this nuanced and difficult subject.

The non-binary nature of sex:

However, “biological sex” can describe a complex suite of traits across multiple organizational levels, including chromosomal inheritance, physiology, morphology, behavior, etc. To capture the full range of sex variability and diversity, we must critically assess our research approaches for studying sex associated traits. In this talk, I will provide practical guidance for conceptual frameworks, experimental designs, and analytical methods for studying and teaching the biology of sex. I invite fellow scientists and educators to conscientiously apply these inclusive approaches, to advance our biological understanding of sex and to encourage academically and socially responsible outcomes of our research.

. . . . Biology is the study of the diversity of life, which includes diversity in sex, gender, sexual behavior, and sexual and romantic orientations. However, the few existing studies of biology textbooks and classrooms suggest that many textbook authors and classroom instructors represent only a narrow swath of this diversity which can lead to an over emphasis on binary sex, conflation of sex and gender, and reinforcement of essentialisms.

Biological sex is a complex and highly variable trait; however, overly simplistic explanations are common in undergraduate biology classrooms. Here we test the impact of an accurate approach to teaching about the diversity of biological sex in organismal biology (‘treatment’ lecture) and compare this approach to a ‘traditional’ lecture section of the same introductory biology course.

The harm of teaching sex “wrongly”.

Although science is thought to be objective and free of emotion, many people are uncomfortable talking about the biology of sex. That discomfort and fear leaves room for hostile attacks on the science of sex to easily propagate through political and social channels. This creates unique challenges for educators in this area. In this presentation, I will discuss the biological basis of sex and sexual diversity from the perspective of a developmental biologist. The hierarchical nature of development connects genetics to phenotypes. Development dictates how sexual diversity emerges within species. The evolution of development dictates how sexual diversity arises among species. I will use development to demonstrate how biologists can distill complexity down into understandable chunks to address the most pervasive misconceptions about sex, especially those actively being used to take away
people’s rights.

. . . To more fully characterize the current range of narratives about sex, gender, sexual behavior, and orientation (SGBO narratives) present in undergraduate biology courses, we interviewed a national sample of 53 biology majors whose genders do not align with the sex they were assigned at birth (i.e., trans-spectrum students) about the SGBO narratives they encountered in biology courses.

We analyzed interviews using reflexive thematic analysis with the goal of identifying SGBO narrative in biology content and how these narratives supported or harmed these students’ sense of belonging in biology classrooms.  We found five SGBO narratives that harmed trans-spectrum students’ sense of belonging.  We also found three narratives that supported trans-spectrum students’ belonging.  These narratives could manifest in the classroom in multiple ways ranging from short disclaimers to elaborate case studies. The ways the narratives manifested influenced their impact on at least some students. These narratives and how they manifest provide potential teaching suggestions to both support trans-spectrum in STEM classrooms and more accurately teach the diversity of biology of sex, gender, sexual behavior, and orientation.

(Continuing the last quote in the section just above):

. . . We show that (1) the treatment lecture has a positive impact on feelings of inclusion for LGBTQIA+ students, (2) the treatment lecture had a positive impact on LGBTQIA+ and TGNC (transgender and gender nonconforming) student experiences in the course compared to other students. . .

This is not a huge deal, but I don’t think that one should distort the most widely accepted definition of sex to avoid offending people who don’t think they adhere to it.  I can’t see any other reason for this symposium. And yes, sex is binary, and that’s universal: there are only two types of gametes, and this holds across all animals and vascular plants. It’s not only universal but useful, for the binary enables us to understand one of the most important phenomena in biology: sexual selection, a form of selection that leads to differences between males and females. Of course teachers should be sensitive to their audience and not denigrate those who feel non-binary, but they should also teach the conventional wisdom about sex, which is apparently not going to happen at this symposium.

Once again, if both sex and race are social constructs, why is it okay to declare you’re of your non-natal sex, but not your non-natal race?

May 12, 2025 • 9:30 am
I was just reading Richard Dawkins’s engrossing essay on sex, gender, and wokeness, and something struck me—a notion that’s not original since it occurred to Rebecca Tuvel when she wrote her infamous essay for Hypatia, a feminist philosophy journal, on “transracialism” Tuvel’s essay pointed out the philosophical and moral parallels between declaring you’re a member of your non-natal “race” (again, I prefer “ancestry”) and declaring that you’re of  your non-natal sex.  Yet Tuvel’s philosophical analysis of this issue, an analysis which I applauded, got her in hot water. As Wikipedia notes:

 

The feminist philosophy journal Hypatia became involved in a dispute in April 2017 that led to the online shaming of one of its authors, Rebecca Tuvel, an assistant professor of philosophy at Rhodes College in Memphis.  The journal had published a peer-reviewed article by Tuvel in which she compared the situation of Caitlyn Jenner, a trans woman, to that of Rachel Dolezal, a white woman who identifies as black. When the article was criticized on social media, scholars associated with Hypatia joined in the criticism and urged the journal to retract it.  The controversy exposed a rift within the journal’s editorial team and more broadly within feminism and academic philosophy.

In the article—”In Defense of Transracialism”, published in Hypatia‘s spring 2017 issue on 25 April—Tuvel argued that “since we should accept transgender individuals’ decisions to change sexes, we should also accept transracial individuals’ decisions to change races”.  After a small group on Facebook and Twitter criticized the article and attacked Tuvel, an open letter began circulating, naming one of Hypatia‘s editorial board as its point of contact and urging the journal to retract the article. The article’s publication had sent a message, the letter said, that “white cis scholars may engage in speculative discussion of these themes” without engaging “theorists whose lives are most directly affected by transphobia and racism”.

On 1 May the journal posted an apology on its Facebook page on behalf of “a majority” of Hypatia‘s associate editors. By the following day the open letter had 830 signatories, including scholars associated with Hypatia and two members of Tuvel’s dissertation committee. Hypatia‘s editor-in-chief, Sally Scholz, and its board of directors stood by the article.  When Scholz resigned in July 2017, the board suspended the associate editors’ authority to appoint the next editor, in response to which eight associate editors resigned.  The directors set up a task force to restructure the journal’s governance.  In February 2018 the directors themselves were replaced.

And of course Rachel Dolezal was also demonized when she was outed as having been born white although claiming she was black. She was fired as president of the local NAACP, and, as Wikipedia notes, “dismissed from her position as an instructor in Africana studies at Eastern Washington University and was removed from her post as chair of the Police Ombudsman Commission in Spokane over ‘a pattern of misconduct'”. All for saying she was black when she was born white. I do believe Dolezal assumed her black identity honestly. It didn’t seem to be a ruse, and, indeed, why would she fake being a member of an oppressed minority unless she really believed it. It surely wasn’t a trick or a ruse.

Richard has been writing about this disparity/hypocrisy for years, most notably in his website post, “Race is a spectrum. Sex is pretty damn binary.”  The title is of course correct, but pointing it out on Twitter cost Richard the 1996 Humanist of the Year Award from the American Humanist Association. And that was for simply raising the question of any relevant difference between being “transracial” or “transsexual”. The AHA acted shamefully in that case, and I’ve washed my hands of it.

Indeed, since race is more spectrum-ish than is sex, it would seem to be MORE JUSTIFIABLE to say you’re a member of a non-natal race than of a non-natal sex.  After all, people like Barack Obama are of mixed ancestry, and can claim whatever they want with biological justification (in his case, white or black).  But if he felt more Asian, why couldn’t he claim he was Asian? After all, race, like sex, is supposed to be a social construct.

This came back to me when I considered the case of Kat Grant and her essay for the Freedom From Religion Foundation (FFRF), which I documented here. That fracas resulted in my published response being taken down, with the consequence that I resigned from the FFRF along with Richard and Steve Pinker.  And the FFRF declared that it dissolved the honorary board of which we were all members (though, curiously, it’s still on the web). Grant’s essay, “What is a woman?” implicitly accepted sex as a social construct and ended this way (bolding is mine):

All of this is to say that there is an answer to the question “what is a woman,” that luckily does not involve plucking a chicken from its feathers. A woman is whoever she says she is.

Yes, a woman is whoever she says she is. Clearly, sex is a social construct here, and you can be whatever sex you want, regardless of your natal gamete-producing system.  Grant was widely applauded by many on the gender-extremist side, while my response was taken down by the FFRF for being hurtful and offensive (you can still read it here, here or here).

 

This fracas, which I call “The KerFFRFle,” has reminded me of the seeming hypocrisy of regarding both sex and race as social constructs, but allowing you to declare whatever sex you feel you are, but not allowing you to declare whatever race you feel you are. Transracialism would seem especially laudatory because one would think it would be a bold move to declare you’re of an oppressed minority group. (Again, I prefer “ancestry” or “population” to “race” for reasons I’ve explained many times.)

I am not taking a stand on these issues here, but merely trying, as did Richard, to understand the difference.  And so I ask readers?

Why is it okay (indeed, applauded) to be transsexual but not transracial?

 

Now the editors of Natural History back the non-binary nature of sex, showing their scientific ignorance

May 3, 2025 • 11:30 am

Yesterday when I criticized Agustín Fuentes’s article in Natural History trying (and failing) to show that sex isn’t binary, I gave the magazine a break. After all, it hasn’t been nearly as bad as Scientific American, and I gave it a break because it published a gazillion essays by Steve Gould (yes, some of them were misguided, touting punctuated equilibrium, but they were all entertaining).

But now I’ve changed my mind, for I’ve learned that the editors actually published a justification in the magazine for publishing Fuentes’s piece. I guess they knew it would be controversial, and it is. It’s just flat wrong, but also misleading in a very annoying way: making points about variation within the sexes that have nothing to do with his thesis (and the title of his book from which the article was taken): “Sex is a Spectrum: Why the Nonbinary View is Problematic.”  His presentation shows that some (but not all) aspects of sexual behavior, sexual dimorphism, and so on are more continuous that the discontinuous existence of the sexes themselves. In all animals there are two reproductive systems, male and females, with exceptions ranging in proportion from 0.00005 to 0.00017.  And that, ladies and gentlemen, friends and comrades, is in all relevant respects a binary.

Fuentes, in other words, was attacking an argument that nobody had made, since we all realize there’s variation in sex-related traits, but his thesis was not about that. It’s about whether there is variation in the types of gametes in plants and animals (especially humans) that are the basis for defining sex (actually it’s really a “recognition” of a binary, not an a priori definition designed to impose a false binary on nature). And Fuentes uses many of the bogus tropes employed to “prove” that sex is nonbinary, even showing a photo of a bluehead wrasse, a fish that forms polygynous groups. When the alpha male dies, one female gets rid of her ovaries and develops testes, taking over the top job.  But there are still only two sexes!  I have to say that you have to be either ignorant or tendentious to use this animal as an argument against the sex binary, and Fuentes isn’t ignorant.

At any rate, the editors’ apologia–or rather “explanation”—is below. What burns my onions about this is their contention that “the science behind Fuentes’s thesis. . . is solid.”  The claim that “the number of mating types (often called “sexes”) has been variable over hundreds of millions of years, ranging from two and sometimes three in most animals, to as many as seven in single-celled animals. . ” is wholly misleading.  Well, Dear Editors, all animals and vascular plants have just two sexes (which ones have three?), though single-celled organisms, algae and fungi can have more “mating type”, which I’m okay with calling “sexes”if you want. But Fuentes and the editors, are defending the thesis that animals, including our own species, have nonbinary sex. This is not true.

Note as well that the editors have been taken in by the claim that the variability of “sexual behavior” and of “sexual activity” within and among species show that there is variability in the number of sexes beyond two.  This is a false argument, as anybody who knows biology and isn’t warped by ideology should know.

What bothers me most about this editorial is the editors’ sanctimonious claim that they are acting “in the public interest” by recognizing the “science” in this debate, but the bogus-ness of that science is all on Fuentes’s side. Shame on you, editors of Natural History? Have you actually followed this debate? How can it be that the Supreme Court of the UK has apprehended and resolved this debate better than do editors of a science magazine.

This is what happens when scientists’ work is distorted by their ideology, and by now I shouldn’t have to tell you what the distorting ideology is.

Here is the editors’ preface:

h/t: Robert

Natural History magazine: Agustín Fuentes rejects the sex binary on ideological grounds, but pretends otherwise

May 2, 2025 • 11:00 am

It looks like Natural History magazine has given an implicit endorsement—or at least a platform—to Princeton anthropology professor Agustín Fuentes.  We’ve met him before, and not under pleasant circumstances, as the man is wont to distort science and mislead his readers in the cause of progressive ideology. To see all the pieces I’ve written about him, go here (and especially these pieces here, here, and here.  And for critiques of Fuentes’s misguided accusations that Darwin was a racist who justified and promoted genocide, go here and here, and also see here for one I published in Science with a bunch of evolutionists. Some of these articles show Fuentes deliberately purveying misleading statements to buttress an ideological position. For that seems to be his modus operandi.

Now Fuentes has put his view that sex is not a binary into a new book, an excerpt of which was published in the latest Natural History, a magazine I always liked. This single bad article won’t change my mind about it (as the multiple bad articles in Scientific American did about that rag), but it makes me question the editors’ judgment. Do they know ANY biology? The reason I ask is that the excerpt is so tedious, dreadful, tendentious, misleading, and convoluted that it wouldn’t pass muster in a real scientific journal, and even a scientifically ignorant editor could see the problem with the arguments (and also correct the bad writing).

You can’t go to the article by clicking on the headline; and I don’t have a link, either. I was sent a pdf by a disaffected reader, and that’s what I’ll quote from. Perhaps you can find a copy if you dig around.

The overweening problem with this article is that it doesn’t show that the binary view is wrong, or that biological sex is really a spectrum. What Fuentes does (and he doesn’t really define biological sex) is to show that within the two constructs he takes to represent sex, there is a lot of variation in various traits.  Men don’t all behave in a way that differs from the way all women behave, development of sex is complicated, people of different sex have different “lived experiences” (yes, he says that), the structure of families vary among cultures, and so on.

But of course all of this variation, and the multidimensional definition of sex, neglects the big problem: is biological sex binary?  Yes it is: males have reproductive systems that evolved to produce small mobile gametes (sperm) and females have systems evolved to produce larger immobile gametes (eggs). There are only two types of gametes—no more. Biologists have arrived at this definition for two reasons: it’s universal in all animals and plants, and also because of its utility: the different investment in gametes usually leads to differential investment in offspring,  which explains not only sex differences in behavior, but sexual selection itself, which produces sexual dimorphism in appearance and sexual behavior. The exceptions to a strict binary defined (really “recognized”) this way range from about 1/5600 individuals to 1/20,000, and that’s as close to a binary you can get in biology.

What Fuentes does is throw a lot of sand in the reader’s eyes, showing variation within sexes and across cultures, hoping that at the end the reader will say, “Hey, maybe sex isn’t a binary after all.” But that variation does not touch the thesis he’s trying to depose. The man doesn’t know how to debate, so, like a true ideologue, he changes the ground of argumentation.

First (probably in the nonquoted parts of his book), he defines the sexes in an introductory note as “3Gfemales” and “3Gmales”, referring to “typical biological patterns of association between genetics-gonads-genitals in human bodies.” I presume he means that members of each have has the typical chromosomal constitutions of its type (e.g. XX in females) as well as gonads (that presumably means testes vs. ovaries) and genital morphology. Fuentes adds that “while useful as general categories, not all people fit into the 3G classifications.” So that is his definition, and of course since it involves more than gametes, will naturally be less binary than the biological definition. A male with a tiny penis, for example, perhaps because of a disorder of sex determination, would be called a biological male if he has testes, but is something else according to Fuentes. But Fuentes doesn’t say what such an individual is. How many sexes are there? An infinite number? And is that true of raccoons, Drosophila, and robins?

Okay, here comes the sand, so cover your eyes. I’ll have to use screenshots since I can’t copy and paste from this pdf:

Variation in sexual behavior:

But it is not “human sexuality” that is the binary, but the definition of sex.  Surely Fuentes recognizes that he is deviating from the main issue his book (and this article) is about: the binary nature of defined sex, as seen in every species of animal and plant. That doesn’t mean that sexuality and its expression is binary.  I’m not sure whether there’s a name for this kind of argumentation, but what he’s doing is clear.

He drags in variation in family structure, too:

Again, all this does is refute a binary of families, not of sexes. Why is it in there? What is the sweating professor trying to say?

Fuentes dwells at length on how sex is basically irrelevant in medicine because sexes show variation in their responses to drugs and get diseases at different rates, implying that the binary is all but useless for doctors. I read to my doctor several paragraphs of Fuentes’s screed, and I won’t give his reaction save to say that it was “not positive.” For example, can you even understand this?:

Stable? “Perceived instability”? What is he banging on about? He doesn’t say.

And females are too complicated to deal with in biology, medicine, and health? What is he talking about?  When a patient goes to see a doctor, it’s essential for the doctor to know the patient’s biological sex. Not only are some diseases specific to sexes (prostate cancer, ovarian or uterine cancer) as are some conditions (menopause), but a good doctor will realize that heart disease (and other diseases) can present differently in the sexes, and will investigate further based on that. Females with heart disease, for example, present more often with indigestion-like symptoms than do males. Now of course there are factors other than sex involved in treating a patient (do they drink, smoke, or eat too much?), but saying that sex is pretty much useless when treating patients is simply dumb. It can even be harmful (though he doesn’t say how):

Again, does any doctor pay attention only to sex? I don’t know of one. To be sure, Fuentes grudgingly admits that there are “two sets of reproductive physiologies” that are relevant to medicine, but minimizes the importance of sex. And to be sure, some diseases are recognized and treated identically in males and females, but to ignore biological sex as a doctor is sheer incompetence.

In another example, Fuentes notes that Ambien doesn’t work the way you’d predict in women if you just reduces the male dosage based on a smaller weight of females.  Why doesn’t this work? Because the drug clears from women “3G females” (did the doctors check all the “G”s?) more slowly than from “3G males.”   He uses this difference to attack the sex binary, by saying that we don’t understand why this average difference occurs, saying “asking about the actual physiological response, rather than assuming 3G males and 3G females are different kinds of humans, is a better approach.”

But again, this is irrelevant to the sex binary; it is about the mechanism of a difference between (Fuentes’s) biological sexes.  And, interestingly, one of the mechanisms he suggests is “attention should be focused on the varying levels of acting testosterone in attenuating the effectiveness of [Ambien].”

Testosterone! Well at least that has some connection with biological sex, no? Fuentes then tries to efface the difference in hormone levels by saying this:  “Testosterone is not characterizable as a male or female hormone, but rather by variation in circulating levels among humans, with 3G males usually having much higher levels than 3G males.”

In reality, we’ve long known that both testes and ovaries produce testosterone, but the distribution of salivary testosterone in the sexes is indeed variable in each sex, and there is hardly any overlap between the sexes: Since testosterone prompts the development of secondary sex traits, including behavior, it’s the binary nature of sex that produce an almost nonoverlapping distribution of hormones. But one should not imply, as Fuentes does, that variation of hormone levels in each sex means that the sexes themselves are non-binary.

(From paper): Figure 1. Shown is a depiction of the bimodal distribution of raw, baseline salivary testosterone values (in pg/mL) when including both men (N = 360) and women (N = 407). All saliva samples were collected and assayed by the present author using radioimmunoassay (Schultheiss and Stanton, 2009). The displayed testosterone data were aggregated from several past studies by the author, and for graphical purposes only, exclude eight male participants with testosterone levels between 150 and 230 pg/mL.

I don’t want to go on much longer, but I’ll add that Fuentes conflates sex and gender several times, and uses familiar tropes to dispel the binary, like the existence of hermaphroditic earthworms, which of course produce only two types of gametes, but in one body. He even shows a photo of a bluehead wrasse, which, like the clownfish (but in the other direction), changes sex in social groups (the head of a group of females is male, but if he dies a female changes sex and becomes the alpha-fish).  And like the clownfish, this doesn’t dispel the sex binary because again, there are only two forms, one producing sperm and one producing eggs. Nobody ever claimed that a biological female can gametically transform into a biological male or vice versa. As always, there are only two reproductive systems, classified by their type of gamete. Neither of these animals produces a third type of gamete.

At the end, Fuentes reprises his error of saying that variation within sexes dispels any notion of a sex binary, and even lapses into philosophisizing:

I love the “why and how humans are in the world.” It’s totally meaningless!  But wait! There’s more:

Of course there is intra- and inter-sex diversity in levels of hormones, behavior, sexual behavior, family structure, and so on.  But there is no diversity within a sex about the type of gamete it is set up to produce, either sperm or eggs (or both in the case of hermaphrodites, which Fuentes calls “intersex”).  And that IS a universal truth about being male or female, a truth that was recognized a long time before social justice ideology arose, and a reognition that had nothing to do with that ideology. Now it does, for even a dolt can see that Fuentes’s real aim to to dispel the binary definition of sex in any way he can, for he considers that definition to be harmful to people who don’t identify as either male or female. It isn’t. If the facts get in the way of ideology for people like Fuentes, they either ignore or misrepresent the facts. Here the entire article is a form of misrepresentation.
******************
At my own ending I’ll quote, with permission, part of the email that the reader who sent me this pdf wrote, just because I liked the email:

 

. . . last night, I was flabbergasted to read in the table of contents of the latest issue of Natural History, ‘Sex is a Spectrum: Why the binary view is problematic.”

That rumbling you just heard was SJG [Stephen Jay Gould] and his biologist forebears from this magazine spinning in their graves. Or so I infer.

OK, I am not a biologist and wouldn’t even try to play one on TV, and so wouldn’t claim the credentials or background to properly critique this. But I do have to wonder at the author’s writing in pretzel knots to avoid, for example, using the term “women” (preferred: “Humans with uteri” [p. 23]), or writing things I find hard to swallow (“the number of mating types (often called “sexes”) per kind of species…[is] two and sometimes three in most animals…”). I’d really like to know the animals that have three sexes (and what the third kind is called, and who it mates with).

h/t: Alex, Robert

Same-sex sexual behavior documented in many mammals: does it mean that similar behavior in humans is “natural”?

April 29, 2025 • 9:45 am

The Naturalistic Fallacy, which most of you surely know, it the erroneous equation of what does exist with what should exist.  Discussed extensively by Hume, it is the false equation of “is” with “ought”. In biology, it takes the form of observing some behavior in animals that is similar to a behavior in humans, and then justifying or saying the human behavior “natural”  or “good” because we see it in other species.

But this is a bad argument, for it cuts both ways. After all, animals show a lot of behavior that would be considered reprehensible or even immoral in humans.  In fact, Joan Roughgarden wrote a book, Evolution’s Rainbow, which describes sex and gender diversity in nature as an explicit way of justifying similar behaviors in humans as good—because they are natural. I reviewed the book for TLS and wrote this bit (review no longer online but I can send a copy).

Coyne, J. A.  2004.  Charm schools. (Review of Evolution’s Rainbow, by Joan Roughgarden). Times Literary Supplement, London. July 30, 2004 (No. 5287), p. 5.

But regardless of the truth of Darwin’s theory, should we consult nature to determine which of our behaviours are to be considered normal or moral? Homosexuality may indeed occur in species other than our own, but so do infanticide, robbery and extra-pair copulation.  If the gay cause is somehow boosted by parallels from nature, then so are the causes of child-killers, thieves and adulterers. And given the cultural milieu in which human sexuality and gender are expressed, how closely can we compare ourselves to other species? In what sense does a fish who changes sex resemble a transgendered person? The fish presumably experiences neither distressing feelings about inhabiting the wrong body, nor ostracism by other fish. In some baboons, the only males who show homosexual behaviour are those denied access to females by more dominant males. How can this possibly be equated to human homosexuality?

The step from “natural” to “ethical” is even riskier. As the philosopher G. E. Moore argued, identifying what is good or right by using any natural property is committing the “naturalistic fallacy”: there is no valid way to deduce “ought” from “is”. If no animals showed homosexual behaviour, would discrimination against gay humans be more justified? Certainly not. Roughgarden’s philosophical strategy is as problematic as her biological one.

Now a 2022 paper in Nature Communications had the potential to demonstrate the same fallacy, but fortunately the authors went to great lengths to avoid that  The same, however, is not true of a new take on this paper in a new article in ZME Science, which gave a précis of the paper and stepped on the Fallacy’s tail.

First the Nature paper itself, which you can access by clicking on the article below, or by reading the pdf here.

It’s a good paper on the evolution and phylogeny of “same-sex sexual behavior” in mammals, which they define as “transient courtship or mating interactions between members of the same sex“.  

Note that it’s “transient,” which explicitly excludes homosexuality, most notably in humans, which is a persistent sexual attraction to members of one’s own biological sex.  This form of transient sexual interaction is surprisingly common—a conservative estimate is 4% of all animal species, and, as the authors say, [includes] “all main groups from invertebrates such as insects, spiders, echinoderms, and nematodes, to vertebrates such as fish, amphibians, reptiles, birds, and mammals.”

Now there are two ways to explain a behavior that seems on its face maladaptive. Why would you engage in sexual behavior that doesn’t involve passing on your genes? One hypothesis is that it’s just a nonadaptive byproduct of other behaviors: a general drive to mate when the appropriate mates aren’t available, or simply mistaken identity.  But the authors investigate two hypotheses that it is adaptive, and give some tentative evidence for that.

First, the results:

  • The authors did a comprehensive survey of same-sex behavior (defined above) in 2546 species of mammals, and superimposed species with and without such behavior on their phylogenetic tree. The object was to see how many times the behavior evolved independently, and whether it was present in the common ancestor of a group (and thus could be passed along to its descendants). Here’s one of those phylogenies with the caption. (You needn’t worry about the details or summary, as I’ll give it below).
(from paper) Phylogenetic distribution of the presence of same-sex sexual behaviour in males and females in the subset III (see methods). The state of the mammalian ancestral nodes was assessed using maximum likelihood estimation (black: same-sex sexual behaviour displayed by females; yellow: same-sex sexual behaviour displayed by males; purple: same-sex sexual behaviour displayed by both sexes). The silhouettes of representative mammals (downloaded from http://www.phylopic.org) illustrate the main mammalian clades. They have a Public Domain license without copyright (http://creativecommons.org/licenses/by/3.0).

A summary:

  •  The behavior was reported in 261 mammalian species
  • Same-sex sexual behavior appears to be equally common in males and females, and the behavior in both sexes tends to be correlated across groups. That is, male and female same-sex behavior is more likely to both appear in the same species than if it either were distributed randomly among groups.
  • It was not possible tell, using phylogenetic analysis, whether same-sex behavior was likely to be a trait in the ancestor of all mammals, but was NOT likely to be a trait in the ancestor of all placental mammals.
  • The behavior seems to have evolved independently in many lineages, so same-sex sexual behavior seems to be a case of “convergent evolution.”
  • The behavior is correlated with whether or not a species is social. If it is social, there’s a significantly higher probability of same-sex sexual behavior. (Remember that this is a correlation and doesn’t imply that sociality prompts the evolution of such behavior. The behavior could simply result from iondividuals in social species being closer to other individuals than those in non-social species.)
  • The common ancestor of all primates does seem to have possessed same-sex sexual behavior.

The association of same-sex sexual behavior with sociality leads the authors to conclude that the behavior evolved by natural selection as a way to enforce inter-individual harmony required by sociality. They mention two such advantages:

1.) Same-sex sexual behavior is a way of creating and maintaining social bonds between individuals in a group; it’s a bonding mechanism.
2.) The behavior could also help prevent or resolve conflicts between members of a group, allowing a hierarchy to develop without injury of death to group members.

The authors mention that these effects have been demonstrated in some species like bottlenose dolphins and American bison, but I’m not familiar with this work, and such conclusions seem to me to be extraordinarily difficult to arrive at. However, I’ll take the authors’ word for it.

The authors are, to be sure, careful in their conclusions. First, they note that nonadaptive hypotheses, like “mistaken identity” could also contribute to the behavior.

Second, and the big one, they note that the behavior they studied is not the same as homosexual behavior like we find in humans.  They do add, however, that it humans do show same-sex sexual behavior in humans (I presume they’re referring to “bisexual” people who have sex with both males and females). From the paper:

However, same-sex sexual behaviour is operationally defined here as any temporary sexual contact between members of the same sex2. This behaviour should be distinguished from homosexuality as a more permanent same sex preference, as found in humans. For this reason, our findings cannot be used to infer the evolution of sexual orientation, identity, and preference or the prevalence of homosexuality as categories of sexual beings Nevertheless, even taking into account this cautionary note, by using phylogenetic inference, our study may provide a potential explanation on the evolutionary history of the occurrence of same-sex sexual behaviour in humans.

They may be right, but I think they should have added that even if same-sex sexual behavior was rare or nonexistent in mammals, its existence in humans is not made “ethical” or “natural” in our species. That would be an example of the naturalistic fallacy, and I emphasize that they do not commit it.  I’d would also emphasize, as I did above, that any sexual behavior between consenting human adults is not for us to judge, regardless of whether or not other species show it, and that such behaviors are fine so long as they’re legal. We don’t need to justify same-sex sexual behavior in humans by seeing it elsewhere in nature. But perhaps this stuff doesn’t belong in a scientific paper. But I want to emphasize it here, as I did in my review of Roughgarden’s book.

As I said, the authors don’t commit the naturalistic fallacy, but the new ZME Science paper below comes close to it. Click headline to read:

Up until the end, this article is okay, but then it can’t resist diving into our own species (bolding is mine).

However, the researchers distinguish between SSSB and sexual orientation. While SSSB involves occasional same-sex interactions, sexual orientation encompasses consistent patterns of attraction and identity, particularly prominent in humans.

While SSSB in animals supports the naturalness of such behaviors, human experiences of sexuality include layers of identity, culture, and personal meaning that go beyond biological explanations. Homosexuality in humans often involves stable sexual orientations and relationships, distinct from the transient or context-dependent SSSB observed in some animal species.

Ultimately, the widespread occurrence of SSSB in mammals, especially primates, strongly suggests that such behaviors are natural and adaptive. Normalizing same-sex behavior as a part of this spectrum aligns with both biological evidence and a broader understanding of human social and emotional complexity.

The last paragraph explicitly says that the results show that homosexuality (one of “such behaviors”) is “natural and adaptive”, as are all “same-sex behaviors” in humans.  The Nature paper says nothing of the sort.  The authors of the Nature paper explicitly exclude homosexuality as not a behavior they studied, but ZME Science lumps it in with other same-sex sexual behaviors, dwspite homosexuality being very different from SSSB.

Again, you do NOT need to justify same-sex sexual behavior, whether it be transient or permanent, by finding examples in the natural world. If we didn’t find any other species with homosexual behavior, would that make it wrong or bad in humans? Of course not! “Is” does not equal “ought,” and I’ll add the corollary that “not is” does not equal “not ought”. The Nature paper is valuable it looking at the evolution of a behavior and testing hypotheses about its adaptiveness, but of course adaptiveness or evolution has nothing to do with the ethics of behaviors between consenting human adults.

Jesus ‘n’ Mo ‘n’ women

April 16, 2025 • 11:00 am

Well, the author came up with today’s Jesus and Mo strip, called “males”, pretty quickly after today’s ruling by the Supreme Court, and even adds the caption “They’ll be fine. Here’s the story.” (It goes to the BBC link.)

As usual, Mo considers himself immune to reason and evidence, as well both he and Jesus should.

UK Supreme Court rules that “woman” refers only to a biological woman

April 16, 2025 • 9:30 am

This is really breaking news, and apparently settles a roiling controversy in the UK that was most intense in Scotland. Today the UK’s Supreme Court, overturning rulings in Scotland, said that, in law, a “woman” is “a biological woman;” and a trans woman, even with a “gender reassignment certificate” does not legally qualify as a “woman”. Below are three real-time news summaries. Excerpts are indented below the headlines.

First, a Scottish law apparently kicked off the controversy. From Reuters:

Wednesday’s British judgment followed legal action by a campaign group, For Women Scotland (FWS), against guidance issued by the devolved Scottish government that accompanied a 2018 law designed to increase the proportion of women on public sector boards.

The guidance said a trans woman with a gender recognition certificate was legally a woman. FWS, which was backed by lesbian rights groups, had lost its case in the Scottish courts, but the Supreme Court ruled in its favour.

And from the official Supreme Court press summary (h/t Athayde):

This appeal arose in response to the definition of the term “woman” in the Gender Representation on Public Boards (Scotland) Act 2018 (“ASP 2018”) and associated statutory guidance. This legislation created gender representation targets to increase the proportion of women on public boards in Scotland. The ASP 2018 and the original statutory guidance defined “woman” as including people: (i) with the protected characteristic of gender reassignment; (ii) living as a woman; and (iii) proposing to undergo / undergoing / who have undergone a gender reassignment process. In 2020, the Appellant, a feminist voluntary organisation that campaigns to strengthen women’s rights in Scotland, challenged this guidance. The Inner House found that this statutory definition was unlawful as it involved an area of law reserved to the UK Parliament (equal opportunities) and therefore fell outside the legislative competence of the Scottish Parliament (“FWS1”).

In all the stuff I was able to read this morning, I was unable to find the definition of a “biological woman”, save that it refers to one’s natal sex, though they don’t mention gametes. The ruling does refer to the binary nature of sex (see below). And the ruling implies as well that the word “man” can mean in law only a “biological man” (see below).

The Guardian:

Bolding is theirs

  • The UK supreme court has ruled that the terms “woman” and “sex” in the Equality Act refer to a biological woman and biological sex, in a victory for gender critical campaigners.

  • Five judges from the UK supreme court ruled unanimously that the legal definition of a woman in the Equality Act 2010 did not include transgender women who hold gender recognition certificates (GRCs). In a significant defeat for the Scottish government, their decision will mean that transgender women can no longer sit on public boards in places set aside for women.

  • It could have far wider ramifications by leading to much greater restrictions on the rights of transgender women to use services and spaces reserved for women, and spark calls for the UK’s laws on gender recognition to be rewritten.

  • Lord Hodge told the court the Equality Act (EA) was very clear that its provisions dealt with biological sex at birth, and not with a person’s acquired gender, regardless of whether they held a gender recognition certificate. That affected policy-making on gender in sports and the armed services, hospitals, as well as women-only charities, and access to changing rooms and women-only spaces, he said.

  • Hodge urged people not to see the decision “as a triumph of one or more groups in our society at the expense of another”. He said all transgender people had clear legal protections under the 2010 act against discrimination and harassment.

  • Gender critical campaign group For Women Scotland, which is backed financially by JK Rowling, celebrated outside the supreme court in London, alongside other campaigners, after the ruling was announced.

BBC:

  • The UK Supreme Court rules that the legal definition of a woman is based on biological sex

  • Judges say the “concept of sex is binary” while cautioning that the landmark ruling should not be seen as victory of one side over another

  • Transgender people still have legal protection from discrimination, the court adds – read the full 88-page judgement here

  • The Scottish government had argued that transgender people with a gender recognition certificate (GRC) are entitled to sex-based protections, while For Women Scotland argued they only apply to people that are born female

  • For Women Scotland says it’s grateful for the decision after a “long road” of legal battles, while charity Scottish Trans urges people “not to panic”

  • The Scottish government says it acted “in good faith” and will work with Westminster to understand the full implications of the ruling

Times of London:

“The terms woman and sex in the Equality Act 2010 refer to a biological woman and biological sex.”

In fewer than 20 words, Lord Hodge settled a legal debate that has raged in British society for years. It also drove a stake through the heart of a central tenet of the trans lobby: that trans women are women.

The 88-page ruling will be pored over by lawyers. The implications for Westminster and beyond will be vast.

. . .Scotland’s first minister has said the Scottish government “accepts” the ruling of the UK Supreme Court on biological sex, and added that “protecting the rights of all” will inform its response.

In a post on X, John Swinney said: “The Scottish government accepts today’s Supreme Court judgment.

“The ruling gives clarity between two relevant pieces of legislation passed at Westminster. We will now engage on the implications of the ruling. Protecting the rights of all will underpin our actions.”

. . .The certificated sex interpretation would have “rendered meaningless” a section of the 2010 Equalities Act dealing with protection from discrimination on the grounds of sexual orientation, according to the ruling.

This interpretation would mean “a trans woman (a biological male) with a GRC (Gender Recognition Certificate) who remains sexually oriented to other females would become a same-sex attracted female, in other words, a lesbian” and would lead to an “inevitable loss of autonomy and dignity for lesbians” as well as impacting lesbian clubs and associations.

The judgment continues: “Read fairly, references to sex in this provision can only mean biological sex. People are not sexually oriented towards those in possession of a certificate.

. . .Kemi Badenoch has said the “era of Keir Starmer telling us women can have penises has come to an end”.

The Conservative leader said: “Saying ‘trans women are women’ was never true in fact, and now isn’t true in law either.

“This is a victory for all of the women who faced personal abuse or lost their jobs for stating the obvious. Women are women and men are men: you cannot change your biological sex.

“Well done to For Women Scotland!”

The full judgement is here (you can also click on the title page below to see the 88-page ruling), and although I haven’t read it carefully, I’ve quoted four bits that seem relevant.

First, the court emphasizes binary nature of sex, but unfortunately doesn’t give a definition of sex, though it claims that it does (my bolding).  The court holds to the “ordinary” meaning of “those plain and unambiguous words”, a meaning that corresponds to the biological characteristics that create a binary. One can interpret that, as I would, as the gametic definition of sex, which is the only definition that creates a dichotomy that, with a few hundredths of a percent of exceptions, conforms to a binary:

171. The definition of sex in the EA 2010 makes clear that the concept of sex is binary, a person is either a woman or a man. Persons who share that protected characteristic for the purposes of the group-based rights and protections are persons of the same sex and provisions that refer to protection for women necessarily exclude men. Although the word “biological” does not appear in this definition, the ordinary meaning of those plain and unambiguous words corresponds with the biological characteristics that make an individual a man or a woman. These are assumed to be self-explanatory and to require no further explanation. Men and women are on the face of the definition only differentiated as a grouping by the biology they share with their group

I Interpret this next part to mean that it’s legal to prohibit trans-identified men (“transwomen”) from competing against biological males.  They don’t talk about trans-identified women, but this presumably holds for them, too.  If so, that means a strict separation of athletic competition by sex, but perhaps sports in which the sexes perform equally on average could be an exception. The fate of trans-identified women in sports is not really discussed or spelled out, at least not that I can see, but if one holds to a biological definition of sex, the legal fate of trans-identified women would be the same as that of trans-identified men.

236. On the other hand, a biological definition of sex would mean that a women’s boxing competition organiser could refuse to admit all men, including trans women regardless of their GRC status. This would be covered by the sex discrimination exception in section 195(1). But if, in addition, the providers of the boxing competition were concerned that fair competition or safety necessitates the exclusion of trans men (biological females living in the male gender, irrespective of GRC status) who have taken testosterone to give them more masculine attributes, their exclusion would amount to gender reassignment discrimination, not sex discrimination, but would be permitted by section 195(2). It is here that the gender reassignment exception would be available to ensure that the exclusion is not unlawful, whether as direct or indirect gender reassignment discrimination.

The part below implies that the ruling also holds for the word “man”, which has to mean “biological man” rather than a biological woman who has a GRC or identifies as a man.

264. For all these reasons, this examination of the language of the EA 2010, its context and purpose, demonstrate that the words “sex”, “woman” and “man” in sections 11 and 212(1) mean (and were always intended to mean) biological sex, biological woman and biological man. These and the other provisions to which we have referred cannot properly be interpreted as also extending to include certificated sex without rendering them incoherent and unworkable.

Finally, this last part disposes of the Scottish government’s regarding one’s sex as being that given on a Gender Recognition Certificate (GRC).  That means that, in Scotland and all over the UK, a transwoman is not identical to a biological woman, nor a transman to a biological man.  The mantras “a transwoman is a woman” and a “transman is a man” now hold no legal meaning.

. . . 266. For all these reasons, we conclude that the Guidance issued by the Scottish Government is incorrect. A person with a GRC in the female gender does not come within the definition of “woman” for the purposes of sex discrimination in section 11 of the EA 2010. That in turn means that the definition of “woman” in section 2 of the 2018 Act, which Scottish Ministers accept must bear the same meaning as the term “woman” in section 11 and section 212 of the EA 2010, is limited to biological women and does not include trans women with a GRC. Because it is so limited, the 2018 Act does not stray beyond the exception permitted in section L2 of Schedule 5 to the Scotland Act into reserved matters. Therefore, construed in the way that we have held it is to be construed, the 2018 Act is within the competence of the Scottish Parliament and can operate to encourage the participation of women in senior positions in public life.

In toto, the ruling seems fair to me, as I never thought that, say, a “transwoman is a woman” and the same for transmen, as I’ve always adhered to the biological sex definition, which gives an almost 100% binary based on one’s evolved system for either producing large, immobile gametes (women) or small mobile gametes (men). This binary holds for all species, but the terms “woman” and “man” have been reserved for humans.  It does not “erase” trans people, giving them the same rights as everyone—with the exception of a person of one sex inhabiting spaces that properly belong to people of the other sex (sports, jails, locker rooms, etc.)  And as I’ve said endlessly, in all situations where you don’t need sex-specific spaces, trans people should have all the rights of everyone else, and should be treated like everyone else.

h/t: Pyers, Geoff