Category: sex

Another journal drinks the Kool-Aid

October 13, 2026 • 9:45 am

The American Journal of Biological Anthropology was formerly The American Journal of Physical Anthropology but, according to reader who sent me this link, the name changed, presumably to reflect the changing nature of the field. I quote:

It is the flagship journal of the AABA and it used to be rigorous science only.  The latest special issue is filled with this nonscientific nonsense.  “Queering Biological Anthropology: uses of LGBTQIA+ knowledge and queer feminism in research”. It’s ridiculous and embarrassing.
You can see the table of contents at the last link above. Yes, a compendium of biological anthropology on sex and gender could potentially contribute to human understand of our personas and social interactions, but this one ain’t it.  Here are a few select articles, and I’ll give a quote or two from each (click on the headline to read the free bits; excerpts are indented, and bolding is mine).

Here’s the phenomenon:

Callitrichids are equally notable as chimeras, a term referring to organisms whose cells are derived from two or more distinct zygotic lineages (Anderson et al. 1951). Among mammals, small numbers of chimeric cells (i.e., “microchimerism”) are thought to be present in all placental species (Gammill and Harrington 2017; Nelson 2012). In callitrichids, however, chimerism routinely occurs on a much larger scale. Within this taxon, chimerism occurs in conjunction with the production of fraternal twins and other multiples, which is the typical birth pattern for all but callimicos (Ah-King and Tullberg 2000; Harris et al. 2014).

That’s interesting, but in the hands of an ideologue the finding allows one to go wild with speculation:

This article demonstrates how queer monster theory can illuminate the cultural boundary-work that stabilizes biological categories of sex and reproduction as well as the kinship claims that often follow. Read as monstrous informants, callitrichid chimeras make visible how “monstrosity” is employed to police these categories in human and nonhuman primates alike, as well as what is at stake when that policing is normalized. When primatology defaults to inherited assumptions about sex and reproduction, it risks not only mischaracterizing its study species but lending scientific authority to the broader cultural machinery of queer monsterization and erasure.

The promises of monsters and monkeys therefore carry epistemic and ethical obligations. Meeting them is, in a sense, a monstrous practice; it requires connections and conversations across subfields and sustained attention to the entanglements of science and sociopolitical dynamics. Yet these obligations can also begin with small methodological choices: specifying the traits being measured rather than using “sex” as a silent binary proxy; defining and justifying what counts as “reproduction” and “fitness” within a given analysis; and acknowledging nonbinary sex and nonreproductive individuals without casting them as aberrant or without value. Practiced in these ways, primatology and biological anthropology can begin to unsettle naturalized bias rather than reproduce it.

In fact, the whole issue is permeated with the view that sex is nonbinary. Here’s another example, one of two article that bemoans the fact that “gender” (presumably how one identifies with respect to sex)

A quote:

Intersectional feminism and queer theories may also be used to challenge sexist and cisgenderist biases that can harm sex- and gender-diverse individuals. Striving to de-center patriarchal ideology, feminist history highlights the shared goals of gender equality and equity. Feminist anthropology, specifically, teaches cultural competence and limits patriarchal biases in forensic casework. A rich understanding of intersectional feminism can help forensic practitioners better understand sex and gender variability. A more feminist forensic anthropology could greatly improve the communal impact of medicolegal practitioners across the U.S. Queer theory aims to critique assumptions related to “atypical” bodies by normalizing the spectrum of human sex and gender diversity. Advocating against biological determinism, integrating queer theories in medicolegal investigations can help ensure that documents and datasets are reflective of individuals’ biological and cultural experiences. Discussions on queering bioarchaeology emerged around the start of the century, with scholars such as Sabrina Agarwal, Pamela Geller, Sandra Hollimon, and Julie Wesp outlining the importance and utility of queer theory and methods in skeletal assessments and conceptualizations of the human body (e.g., Geller 2005, 2008, 2009a, 2009b, 2019; Hollimon 1996, 2001, 2011; Wesp and Agarwal 2017). Failure to recognize both biological and cultural influences on the skeleton risks perpetuating scientism, presentism, and bio-colonialism (Geller 2005, 2009b, 2019; Hollimon 2011). Using queer theory in forensic anthropology can help improve medicolegal case resolution by broadening identification efforts and collaboration with living communities.

Another search for nonbinary sex in skeletons:

This author use sa bogus overestimateion of true intersex individuals, and then, since there are really no data showing what the skeletons of such individuals look like, they simply make predictions. Again, there’s a general denial that there are distinguishable sexes, as well as the usual emphasis on sex-related traits which, of course, we’ve long known are more variable than sex itself. We still have only two types of gametes.

Blackless et al. (2000) have estimated that approx. 1.7%–2.3% of all humans are intersex. Fausto-Sterling (2000a) similarly estimated that intersex people comprise 1.7% of the global population, revised from an earlier estimate of 4% (Fausto-Sterling 1993). If accurate, these estimates indicate that intersex is not rare in population genetics terms (Astorino 2019), since “rare” traits are exhibited by < 1% of individuals in a given population (Hartl et al. 1997; Jobling et al. 2013). Researchers in the social sciences have noted that this frequency estimate is comparable to the global frequency of humans with natural red hair—a trait that is generally not considered “rare” by medical professionals or many cultures (Dreger 1998; Karkazis 2008a; Davis 2015). In other vertebrates, it is unclear how common intersex is; while the frequency of other forms of sex diversity has been more comprehensively studied across higher vertebrate taxa (Ashman et al. 2014; Nemesházi and Bókony 2023), similar data on intersex are not available.

. . . . Given these frequencies, it may be inaccurate to characterize humans as sexually dimorphic (Blackless et al. 2000). Astorino (2019) suggested that humans may be conceptualized not as sexually dimorphic, but as sexually polymorphic. Dunsworth (2020) proposed referring to “sex differences” instead of sexual dimorphism. McLaughlin et al. (2023) argued that sex is multivariate, where many individual traits—each of which may or may not conform to a binary distribution—collectively constitute what is typically considered a single variable. Similarly, Smiley et al. (2024) asserted that individual sex variables each represent different aspects of sex, which may have complex, dynamic relationships with other sex variables, and suggested that researchers operationalize specific, measurable sex variables appropriate for a given study, each of which may be characterized as monomorphic, dimorphic, or multimorphic.

Despite the fact that sex variation has been noted to be complex in humans, sex is still most commonly defined as sexually dimorphic by biological anthropologists and evolutionary biologists.

Bonobos used to rectify the claimed erasure of lesbian and bisexual relationships:

The title of this paper “Just gal pals!” refers to the heteronormative tendency to erase lesbian and bisexual relationships and is a memeified response by the LGBTQ+ community online to such erasure (Warburton 2021). We believe it also encapsulates the way researchers over the decades have described bonobo GG rubbing: Wow look at those two female bonobos (gal pals) and their strong social bond or just two female bonobos (gal pals) reducing tension. Entrenched biases make the alternative—that two female bonobos are having sex—one of the last available explanations that researchers explicitly acknowledge in the scientific literature. This may be why sexual motivations are omitted from hypotheses for the function of GG rubbing (Hohmann and Fruth 2000; 2009; Waller 2016). Similarly, while GG rubbing in female bonobos has been emphasized, male–male sexual behavior in bonobos and other primates is often overlooked. Media portrayals of female–female sexuality in humans are often framed for consumption by the male gaze and/or imply that the women involved are “testing” or “experimenting” while not invalidating a heterosexual identity (Diamond 2005). Thus, female–female sexuality among humans, particularly for bi/pansexual women, is often not viewed as valid, and sexual relationships among women are viewed more favorably than those among men (Worthen 2013; Bettinsoli et al. 2020). As a result, recognition of female–female sexuality in our closest relatives may also be perceived as less directly threatening to patriarchal hegemony in humans.

Now I haven’t read the whole issue, or any article in great detail, as that would cause severe damage to my alimentary canal. Regardless, this issue, for which papers were solicited, appears to be driven not by a search for truth but by a drive to promote “progressive” ideology. Not only do we see the claim that traditional anthropology has caused great harm (see above about erasing lesbian and bisexual relationships), but that these papers will rectify that harm. The science is mission-driven rather than knowledge-driven.

Other harm appears to come from the claim that sex in humans is binary, with misguided biologists like me recognizing that humans have but two types of reproductive apparatus: those designed to produce eggs or sperm. I’ve defended that position assiduously while recognizing that there is a very low frequency (about 1/5000) of true intersex individuals.

Overall, this shows the growing tendency of biological anthropologists to distort science for ideological ends. The claim that there are more than two sexes, or that sex is a continuum, is of course made to buttress the idea that individuals who feel that they’re not of their natal biological sex will be harmed by the sex binary. It is a way of providing consolation to nonbinary people (I’m talking about gender, not sex.) That idea bogus, of course, but it’s these well-meaning but careerist scientists—those who infuse their “findings” with ideology—who do the real damage.

And of course I make no comment about the other papers in the contents that I haven’t looked at.

h/t: Callum

My Quillette review of Steve Stewart-Williams’s new book on sex differences in humans

July 30, 2026 • 9:30 am

Steve Stewart-Williams has recently published an informative and readable new book (link at the screenshot just below), and my 4000-word review of it for Quillette just appeared (click second screenshot below for the review):

As I implied, my review is laudatory, with only a few (really one) reservations, which is minor. It’s not a “page turner”, either, which means that you have to retain some fairly sophisticated biology in your head as you read it—stuff about sexual selection. This will discourage those people who still actually read books (they will also find my review long, as I have to explain the thesis, the nature of sexual selection, and the data).

As I say in my review, Steve’s point is to suss out the causes of human sex differences “above the neck” (i.e., in aptitudes, behaviors and preferences). The differences could in principle be due to biases, socialization, or genes (“innate” stuff), though males and females have almost exactly the same set of genes save for the crucial SRY “sex-determining gene” on the Y chromosome.  Insofar as sex differences in physiology, behavior, preferences, and morphology are genetic, they must be due almost entirely to differences in expression of a nearly identical set of genes—expression differences part of a developmental cascade kicked off by whether the crucial SRY gene is expressed.

I’m allowed to quote just three paragraphs here, so here are three I selected:

But the questions [Larry Summers] raised remain, and there are several. First, are there real differences in behaviour and aptitude between the sexes? Although the sexes have obvious physical differences, many “blank-slaters” think that things are roughly equal from the neck up, with no average sex differences in thoughts, preferences, or behaviours. Second, if there are such differences, where did they come from? Are they due to sociocultural influences, like patriarchy and socialisation, or are they largely innate—that is, based on genes? Finally, if some sex differences are inherited, did the genes involved arise by natural selection in our ancestors, with the differences enhancing reproduction? Answering “no” to all of these questions makes you a full-blown blank-slater, while answering “yes” makes you a genetic determinist—perhaps the most damaging label that can be stuck on a liberal thinker.

In A Billion Years of Sex Differences, Steve Stewart-Williams argues that it’s time to engage these questions with data. Summarising existing research, he comes down closer to genetic determinism than to blank-slatism. That is, he sees significant sex differences in thinking, behaviour, and preferences as having a substantial genetic basis, but he recognises too a role for sociocultural influences.

. . . . All of this evidence for innateness—persistence despite discouragement, consistency among cultures and over the ages, developmental trajectories, parallels with other species, and the gender equality paradox—is explained most parsimoniously not by a purely sociocultural hypothesis, but by positing some genetic basis for sex differences. No line of evidence is conclusive by itself, but their “consilience”, the convergence of diverse lines of investigation on innate explanations, is convincing. Stewart-Williams hastens to add that we often can’t rule out some sociocultural basis for large sex differences, but as a whole the pure blank-slate idea just doesn’t hold up. We already knew that for things like height and hairiness; now we also know it for what’s produced by our brains.

Throughout the book, the assumption is, reasonably, that there are just two sexes, and Stewart-Williams doesn’t deal with the faux controversy about the number of biological sexes, nor does he need to. Read my review, if you can, and if you think you’d like the book, get it. Everyone interested in the nature and source of differences in behavior and mentation between the sexes should, I think, be interested in it.

Luana’s revealing class survey of the biological definition of sex

March 17, 2026 • 9:30 am

Yesterday I wrote a bit (well, more than a bit) about a dire paper in Ecology Letters promoting a unusable “multivariate” view of sex and criticizing the gamete-based definition of biological sex recognized by most savvy biologists as the best definition, corresponding to reality, being universal, and being the most useful definition in promoting research. Sadly, but perhaps understandably, the average person wouldn’t be able to define “biological sex”, though.  This was demonstrated yesterday by my colleague Luana Maroja, an evolutionary biologist who works at Williams College in Massachusetts.

This semester Luana is teaching Evolution to undergraduates, and, fortuitously sent me the slide below with a note:

Today I taught about sex binary in Evolution.  Here is the clicker slide I presented and the responses:

A “clicker slide” is one which gives students in the class a chance to vote on alternatives. Each student has a device that records their vote. In this one, Luana asked her students to choose one of five alternatives to answer the question, “How many biological sexes in animals and vascular plants?” (Note that “biological” is in italics; she’s not talking about gender but gave the students the chance to conflate sex and gender. They have five choices:

 

A.  Binary (males and females)
B.  Three sexes (males, females, and intersexes)
C. 4 sexes (males, females, intersexes, and hermaphrodites
D. Over 150 sexes (from “agender” to “zoogender”) .
E. Impossible to tell since sex is a continuum.

First the five alternatives were presented and then Luana put a box around the correct answer, which is shown below (click to enlarge):

 

Note that by far the most common answer was C:  four sexes: males, females, intersexes, and hermaphrodites.  The correct answer, two, was less than half of that at 21%, followed by a tie of 14% for “three sexes” and “over 150 sexes.”  The “impossible to tell because sex is a continuum” answer garnered only 7% of the votes (in this small class that is just one person): I guess the students have not yet been propagandized by the likes of Agustín Fuentes and Steve Novella.

Intersex individuals do not represent a distinct biological sex because their sex is indeterminate, while hermaphrodites are simply individuals that have both sexes (both gamete types) in single individuals. They are common in plants but, since they produce sperm and eggs only, and not any other types of gametes, combine both functions in one individuals. Hermaphrodites are quite rare in animals though more common in groups like worms.  “True hermaphrodites”—individuals capable of delivering both types of gametes—are not present in mammals, and I’ve found only a handful humans with both testicular and ovarian tissue, none of which had viable gametes of both types.

These students are smarter than the average American because Williams is a highly rated and selective undergraduate college. Nevertheless, they have no idea that sex in animals and plants is a binary representing two types of gametes: a large immobile gamete, characterizing females, and a small, mobile gamete, characterizing males.

You can see why so many people are susceptible to people who argue that sex is not a binary: they are already predisposed to believe that.

Luana asked me to mention that “the class is small and this is an improvement over what I had two years ago (the last time I surveyed the students). At that time most people chose the last option.”  (continuum). When I asked her what the improvement was, she added that, “The improvement is because they are not answering E anymore and many more people are picking the correct response.  ‘C’ is not as bad as ‘E'”

But note this other info from Luana, “With a small class like this one, we really don’t know where the bulk of students stand, but it is also important to notice that this is a 300 level class, thus all students already had Biology 102 (organismal biology) and thus should know better.”  Bio 102 is apparently not doing its job!

Of course you’ve learned by now that the entire debate about how many biological sexes there are is spurred solely by ideology.  If gender activists were not so eager to promote the incorrect idea that sex and gender are the same thing, and that we should confect scientific definitions to match people’s view of themselves, then biologists wouldn’t be arguing about this stuff. Alas, even some biologists (I’ve named two) have been seduced by the sirens of ideology. Others include the Presidents of the three major evolution societies. As I wrote on February 13 of last year:

. . . . the Presidents of three organismal-biology societies, the Society for the Study of Evolution (SSE), the American Society of Naturalists (ASN) and the Society of Systematic Biologists (SSB) sent a declaration addressed to President Trump and all the members of Congress. (declaration archived here)  Implicitly claiming that its sentiments were endorsed by the 3500 members of the societies, the declaration also claimed that there is a scientific consensus on the definition of sex, and that is that sex is NOT binary but rather some unspecified but multivariate combination of different traits, a definition that makes sex a continuum or spectrum—and in all species!

As it happened, a letter with about 125 signers from the evolutionary biology community took issue with the embarrassing “sex spectrum” claim, and the Tri-Society presidents decoded to remove it from the Internet, though I archived it and you can see it at this link. It stands as depressing testimony of how even influential evolutionary biologists can distort science when they want to conform to an au courant ideology.

But enough; the survey above gives you an idea of the extent of public misunderstanding of biological sex.

Another journal drinks the Kool-Aid: Ecology Letters publishes a misguided article that “There is no consensus on biological sex”

March 16, 2026 • 9:45 am

Ecology Letters, which I thought was a reasonably respectable journal, has now accepted a “viewpoint” article arguing that there is no consensus on biological sex, and that a definition based on gamete size—a consensus if ever there was one—is just viable as “multivariate” definition that incorporates a combination of chromosomes, genetics, and morphology.

They’re wrong and misguided in many ways, but, as Colin Wright notes in a tweet at bottom, there are so many mistakes and misconceptions in this paper that it would take a full reply to the journal to correct them.  I’ll just tender a few comments here, but you can read the paper for free by clicking the title below, or download the pdf at this site.

The authors give three definitions of sex: the classical one based on gamete size (males have small, mobile gametes, females large and immobile ones); a “multivariate” one, popular in some nescient quarters, that defines sex base on some combination of morphology, chromosomes, and “genetics,” and, finally something called “sex eliminativism,” which “eliminates the concept of sex altogether.” They graciously admit that they won’t discuss the last one because “rigorous research on sex-based variation remains vital.” True enough.

But they add that the “rigorous research” they propose be done “also challenges simplistic and harmful ideologies of the sex binary”.  This is a red flag that their criticism of the sex binary is partly (if not wholly) based not on biology but on ideology, for the “sex binary” is described as “ideological” and “harmful”. (They are talking, of course, about how a binary may harm people who don’t see themselves as fitting into it.) They later add that there are “ethical and political implications of defining sex.”  Only if they care to draw them; most real biologists don’t.

But sex was defined by gamete type long before the “gender” ideology began questioning the view that there are two sexes. And definition has been widely adopted, as I’ve said, not on ideology but on universality and utility. (See this discussion by Richard Dawkins.) All animals and vascular plants have only two sexes corresponding to gamete size, so the gametic definition holds across the animal kingdom. That leads to research questions about why this is so: why do animals, for instance, have only two sexes (some rare parthenogenetic species have only one sex: egg-producing females), but not three or more sexes. There are many papers discussing this question, and the answer seems to be that isogamous species evolve by natural selection to be anisogamous ones (two types of gametes), with that state now seen to be an evolutionarily stable to invasion by more sexes. This already shows that defining sex based on gametes is universal among animals and plants and, because it leads to research questions, also utilitarian. It becomes even more utilitarian when we see that the gametic sex dimorphism helps us understand many facts about biology, most notably the morphological and behavioral differences between males and females explained by sexual selection—an approach first suggested by Darwin in 1871.

What are the problems with a biological sex definition? The authors claim that in most cases biologists don’t look at gametes when discussing or enumerating sexes, and that is usually true.  When I divided fruit flies into piles of males vs. females, I looked not at their gametes, but their genitals. This is not a problem because in virtually all species there are proxies for gametes: traits like chromosomes or morphology that are closely correlated with sex. They are not 100% correlated, but pretty close to it.

But that’s not a problem, for the authors don’t seem to realize that there’s a difference between defining sex and recognizing sex.  The binary gamete-based definition is universal (and of course useful), while a definitions based on chromosomes, appearance, or genetics is not universal. (Many species have sex determined not by chromosome type or genetics but by rearing temperature, social milieu, haploidy, so on.) Still no matter how sex is determined, if you look at gamete types you always find two sexes.  Further, the authors don’t tell us how one is to combine the other traits in a multivariate way to define sex in any species. Would they care to give us a multivariate definition of sex for humans (or any other animal)? They refrain—and for good reason: it would be a futile task.

Their other criticisms of gametic sex are that it doesn’t deal with those species like algae or fungi that don’t have morphologically distinct gametes but are isogamous, with gametes looking the same. These species can have dozens of “mating types” based on genes, each of which can fuse only with gametes of a different type. These have long been called “mating types” and not “sexes” by biologists, and are not a problem for most species we’re interested in—including, of course, humans. As Colin notes below:

But anisogamy (reproduction via the fusion of gametes of different sizes) isn’t meant to apply to isogamous organisms (organisms that reproduce via the fusion of same-sized gametes). Anisogamy and the sexes—male and female—are fully intertwined and inseparable. Isogamous organisms don’t have sexes; they have “mating types.” They’re different from sexes, and that’s why biologists aren’t “inclusive” of isogamous organisms when talking about males and females.

The other criticism of gametic sex are just dumb: we can’t tell the sex of an individual before it produces gametes (like young men [in humans, newborn girls already have eggs!]) or after reproduction has stopped and gametes are no longer produced. From the paper:

 . . . this narrow [gametic] definition is not inclusive of reproductive approaches beyond anisogamy (e.g., isogamy) and does not classify organisms before sexual maturity or after reproductive cessation as having a sex.

According to these authors, then, newborn boys do not have a sex (newborn girls do) nor do postmenopausal women or some old men who don’t produce sperm.  That is crazy because the gametic definition of sex involves having the biological apparatus to produce large or small gametes; it does not have to be operational. To quote Colin again:

And the notion that a gamete-based definition doesn’t apply to sexually immature individuals or individuals who have ceased producing gametes ignores that the sexes are defined by having the biological FUNCTION to produce small or large gametes—and things still have a function even when it’s not being currently realized.

Below is a table from the paper comparing the gametic versus “multivariate” definitions of sex (the latter broken down into chromosomes, genetics, and morphology), seeing how useful each of the types is in defining sex in nine species (click to enlarge). Note that only one species, the New Mexico whiptail lizard (Aspidoscelis neomexicanus) is said to defy definition by gametes.  Yet it is called, in the footnoes, a “female only species”.  It is parthenogenetic, formed by the hybridization of two regular species having two gametic sexes, and the hybrids cannot produce males but produce females from unfertilized eggs that are diploid and genetic clones of the mother.  So if it’s hard to define organisms in this species as male or female, why do the authors call it a “FEMALE ONLY SPECIES.”  Because it produces eggs, Jake! It does not defy the binary at all, and you can put a “yes” in the first column where there’s a “no”.

Note that no other form of classification has “yes” all the way down: not chromosomal definitions, not genetic definitions, not morphological definitions (they again make the ludicrous claim that immature individuals don’t have sexes). And when you combine each of the three univariate non-gametic definitions in some multivariate way, you get a mess.  Only the first column, the operational definition using gametes, holds in all organisms. But we already knew that.

There’s another table that’s even more ludicrous. This one points out (as they do in the text, so the table is superfluous) that in some species of hummingbirds, some (not all) females have male-like coloration, even though they have large gametes. There is thus a disparity between the gametic definition of sex and a morphological one. But note that the morphology is used as a species-recognition trait here, not as a way to define sexes. This is one case where a proxy trait for sex doesn’t jibe with the gametes.

Are the females with male-like coloration really males? No biologist would say that, and if you look at the references for the table, you see papers like this (my bolding):

Bleiweiss, R. 1992. “Widespread Polychromatism in Female Sunangel Hummingbirds (Heliangelus: Trochilidae).” Biological Journal of the Linnean Society of London 45: 291–314.

Diamant, E. S., J. J. Falk, and D. R. Rubenstein. 2021. “Male-Like Female Morphs in Hummingbirds: The Evolution of a Widespread Sex-Limited Plumage Polymorphism.” Proceedings of the Royal Society B: Biological Sciences 288: 20203004.

Falk, J. J., D. R. Rubenstein, A. Rico-Guevara, and M. S. Webster. 2022. “Intersexual Social Dominance Mimicry Drives Female Hummingbird Polymorphism.” Proceedings of the Royal Society B: Biological Sciences 289: 20220332.

Falk, J. J., M. S. Webster, and D. R. Rubenstein. 2021. “Male-Like Ornamentation in Female Hummingbirds Results From Social Harassment Rather Than Sexual Selection.” Current Biology 31: 4381–4387.e6.

These all say that the male-appearing hummers are females that have evolved a male-like coloration (they apparently have done to avoid harassment and get more food). These are cases of polymorphism: some of the females look like males, while others look like regular females. The important question is this: why do all the authors call these male-looking birds “females”? It’s not hard to see: they produce large gametes and lay eggs (the authors used other traits associated with female-ness, like body shape in non-mimetic females, to suss out the male-like females).  The females that look like males also show territorial behavior characteristic of males, and that’s because biological males have to acquire territories to attract females. Why do only the males do this? Because of the disparity in gamete size—the male mating strategy is to mate with as many females as they can, while females are more selective. (This is a classic behavioral difference due to sexual selection.)

In sum. the authors only buttress the gamete-based definition of sex in their tables.  They do show argue that, in cases where you can be deceived about gametes by other traits, biologists like ones studying hummingbirds should describe the criteria they use for assessing sex. That seems okay to me and in fact that’s what’s done in the paper. But sure enough, the authors use color as a proxy for gamete size, not the other way around! Gamete size is fundamental. This is one case, where, as Colin says:

. . . every non-gametic view of sex is logically incoherent and self-refuting because they all rely on gametes as the conceptual anchor.

Here the color serves as a clue to what the conceptual anchor is and, sure enough, it’s gamete size.

In the end, this paper is deeply misguided and, I suspect, driven by ideology rather than biology. What else but ideology would cause four biologists to make such incoherent and misleading arguments? I could think of other reasons, but ideology is the most parsimonious (and the most au courant) given that the authors call the sex binary a “simplistic and harmful ideology” (it’s not an ideology, but an observation) as well as claiming that the definition of sex has ethical and political implications.  No, it doesn’t—unless you are an ideologue.

Colin says in his tweet below, “I have reached out to the editors of Ecology Letters asking if they would consider publishing a counter-Viewpoint.” I hope they do. If they don’t, then they are suppressing valid scientific dissent in the name of maintaining a “progressive” ideology. I would like to think that Ecology Letters would do that. Stay tuned.

Here’s Colin’s tweet, which should be expanded to see his take:

🚨ALERT: Top-ranking ecology journal Ecology Letters has published a “Viewpoint” paper titled “There is No Consensus on Biological Sex.”

h/t: Michael

Jesus ‘n’ Mo ‘n’ “woman”

February 20, 2026 • 11:45 am

Here Mo puts on a burqa and asserts that he’s a woman because he feels like one.  Of course this panel is triggering for “progressives,” and, though the strip is six years old and recycled, the artist says this:

A Friday Flashback from almost exactly six years ago. Lost a couple of patrons that day. Let’s see if it happens again.

I suspect it will!

Another critique of Agustín Fuentes’s claim of a sex spectrum in humans and other species

February 1, 2026 • 11:20 am

Although the view that sex is a spectrum, and that there are more than two biological sexes in humans and other species, is still prevalent among the woke, others are realizing that sex in humans (and nearly every other species of plant and animal) is indeed a binary, with a tiny fraction of exceptions in humans. These include individuals with “differences in sex determination” (DSD) and almost nonexistent hermaphrodites. Estimates of exceptions in our species range from 0.02% to 0.005%.

The rise of the “sex is a spectrum” notion is due solely to the rise of gender activism and to people who identify as nonbinary or transgender.  But gender is not the same thing as biological sex: the former is a subjective way of feeling, while the latter is an objective fact of biology based on a binary of gamete types.

I personally don’t care if someone identifies as a member of a nonstandard gender, but I do care when people like Steve Novella, who should know better, argue that biological sex is not a binary but a spectrum. In fact, there are far more people born with more or fewer than 20 fingers and toes than are born as true intersexes, yet we do not say that “digit number in humans is a spectrum.”

It’s a shame that many of those who claim that sex is a spectrum are biologists who recognize the sex binary and its many consequences, like sexual selection. The misguided folks include the three main scientific societies studying evolution, who issued a statement that biological sex was a spectrum, and further that this was a consensus view. (Their original statement is archived here.) The societies then took down their claim when other biologists pointed out its inanity (see here, here, and here). And it’s not only biologists who recognize the ideology behind the claim that sex is a spectrum; the public does, too.  NBC News reported this in 2023 (note the conflation of sex and gender):

A new national poll from PRRI finds Americans’ views on gender identity, pronoun use and teaching about same-sex relationships in school deeply divided by party affiliation, age and religion.

Overall, 65% of all Americans believe there are only two gender identities, while 34% disagree and say there are many gender identities.

But inside those numbers are sharp differences. Fully 90% of Republicans say there are just two genders, versus 66% of independents and 44% of Democrats who believe the same

Sadly, if you’re on the side of truth in this debate, at least as far as the number of sexes go, you’re on the side of Republicans. So it goes. Further, Americans and sports organizations themselves are increasingly adopting the views that trans-identified men (“transwomen,” as they’re sometimes called) should not compete in sports against biological women. This is from a 2025 Gallup poll.

Sixty-nine percent of U.S. adults continue to believe that transgender athletes should only be allowed to play on sports teams that match their birth sex, and 66% of Americans say a person’s birth sex rather than gender identity should be listed on government documents such as passports or driver’s licenses.

Thus, although wokeness is like a barbed porcupine quill: easy to go inside you but hard to remove, I’m pretty confident that the claim of a biological sex spectrum will eventually decline even more. But there are still some ideologues who twist and misrepresent the facts to argue that there are more than two sexes. (The argument centers on humans, of course.)  One of these is Princeton anthropologist Agustín Fuentes, who has written several papers and a recent book arguing for the human sex spectrum. I’ve pushed back on his arguments many times (see here), and wrote a short review of his book Sex is a Spectrum, a book that should be read with a beaker of Pepto-Bismol by your side. There’s another and better critical review of Fuentes’s book by Tomas Bogardus, here,  which Bogardus has turned into his own new book, The Nature of the Sexes: Why Biology Matters.

This post is just to highlight another critical review of Fuentes’s book and his views on sex, one written by Alexander Riley and appearing at Compact. You can get to a paywalled version by clicking on the title below, but a reader sent me a transcript, and I’ll quote briefly from that below.

A few quotes (indented). I don’t know how readers can access the whole review without subscribing:

Fuentes, an anthropologist who has extensively studied macaques, begins with a primer on the evolution of sexual reproduction in life on the planet. To show how “interesting” sex is, he offers the example of the bluehead wrasse, a fish species in which females can turn into males in given ecologies. The example, he says, is “not that weird” in biology.

But the reality is that species like this one most definitely are weird, not only in the animal kingdom, but even among fish, who are among the most sexually fluid animals. Among fish, the number of species that are sexually fluid in this way is perhaps around 500 … unless you know that there are approximately 34,000 known fish species. In other words, even in the most sexually fluid animals, transition between male and female by one individual can happen in only 1.5 percent of the total species. What Fuentes describes as “not that weird” is certainly highly unusual. [JAC: note that switching from male to female or vice versa does not negate the sex binary.]

This sleight of hand is typical of Fuentes’s handling of evidence. He attacks a classic argument in evolutionary biology that differences in male and female gametes (sperm an eggs, respectively) explain many other differences between the two sexes. In short, because eggs are much costlier to make than sperm, females have evolved to invest more energy in the reproductive chances of each gamete compared to males. This bare fact of the gamete difference means, according to the Bateman-Trivers principle, males and females typically develop different mating strategies and have different physical and behavioral profiles.

The distortion below is typical of ideologues who promote Fausto-Sterling’s data even when they know it’s incorrect:

Fuentes notes that what he calls “3G human males and females,” that is, those individuals who are unambiguously male or female in their genitalia, their gonads (the gland/organ that produces either male or female gametes), and genes, do not make up 100 percent of human individuals. He goes on to suggest that at least 1 percent of humans, and perhaps more, do not fit the 3G categories. This is a claim unsupported by the facts. The citation he links to this claim is an article by biology and gender studies professor Anne Fausto-Sterling. The claim made by Fausto-Sterling about the percentage of those who are intersex has been thoroughly debunked. She includes a number of conditions in her category of intersex (or non-3G) that are widely recognized as not legitimately so classified. One such condition (Late Onset Congenital Adrenal Hyperplasia, or LOCAH, a hormonal disorder) makes up fully 90 percent of Fausto-Sterling’s “intersex” category. Individuals with LOCAH are easily classed as either male or female according to Fuentes’ 3Gs, and nearly all of them are able to participate in reproduction as normal for their sex. The percentage of those who are actually outside 3G male or female classes is likely around 0.02% percent, which means that 9,998 out of every 10,000 humans are in those two groups.

What’s below shows that trans-identified men do not become equivalent to biological women when they undergo medical transition:

Transwomen are much more likely to exhibit behaviors of sexual violence and aggression than women. A 2011 study showed clearly that even male-to-female transsexuals who had undergone full surgical transition, and who therefore had undergone hormone therapy to try to approximate female hormonal biology, still showed rates of violent crime and sexual aggression comparable to biological males. They were almost twenty times more likely to be convicted of a violent offense than the typical female subject. This is reason enough to keep individuals who have male hormonal biology out of spaces in which they interact closely with semi-clad girls and women.

And Riley’s conclusion:

The fact that Fuentes can make such ill-founded claims without fearing serious pushback is an indication of how captured academic culture is by the ideology behind this book. A healthy academic culture would not so easily acquiesce to political rhetoric masquerading as science.

Yes, anthropology has been captured—especially cultural anthropology—and, as I said, even some biologists have gone to the Dark Side. I have nothing but contempt and pity for those who know that there are two sexes but twist and mangle the facts to conform to the woke contention that the sexes can be made interchangeable. But I should add the usual caveat that, except for a few exceptions like sports and prisons, transgender people whould be given the same rights as everyone else.

Another sign of people rejecting the “sex is a spectrum” claim is that Fuentes’s book didn’t sell well. Despite coming out less than a year ago. it’s now #301,447 on Amazon’s sales list, and has only 25 customer ratings, totaling 3.8 out of 5 stars. It didn’t exactly fly off the shelves.

Here are two Amazon reviews by savvy readers (note: none of the reviews on Amazon are by me):

 

Videos: Dawkins on sex differences; Neil deGrasse Tyson on sport and sex

October 13, 2025 • 9:30 am

The first article in the new anthology The War on Science (compiled, edited, and with an introduction by Lawrence Krauss) is a piece by Richard Dawkins called “Scientific truth stands above human feelings and politics.”  It’s basically a two-part essay on how ideology has distorted science, with the first part being about Trofim Lysenko’s distortion of Russian genetics under Stalin, and the second bit being about sex and gender, concentrating on the biological nature of sex. In the UnHerd interview below, Richard dilates on the part about sex and gender, but concentrating on the evolutionary biology of sex.  As I’ve said, the book has been attacked by miscreants—many of whom hadn’t read it, but damned it nonetheless because some of the authors were deemed politically unpalatable and because the topic was how the left has damaged science. (“We should”, say these miscreants, “have written only about the damage that Trump and his minions have done to science.”)

Dawkins is one of the people who has brought opprobrium down on the book, because, after all, he’s an “old white man”, a member of the most oppressive group at all. But his age, sex, and race are irrelevant to his essay, which is one of the very best in the anthology.  In his characteristically clear and eloquent writing, he explains what he calls the “universal biological definition of sex” (“UBD”): the now-familiar claim that biological sex is based on relative gamete size. This definition leads ineluctably to the view that sex is binary: there are two and only two forms of gametes in a given species. He underlines something that I’ve also emphasized: the UBD is not only ubiquitous, applying in binary form in all animals and vascular plants, but is also explanatory: the sex binary is the only concept of sex that can explain, usually via sexual selection, a number of phenomena that puzzled biologists before Darwin proposed this form of selection in 1871.

In the UnHerd video discussion with Freddie Sayers shown below, Richard runs through 14 of these phenomena, making an airtight case for the utility of the UBD.  He also takes up issues raised by the Miscreants to try to show that sex is a spectrum: the sequential switching of sex by clownfish and wrasses (they’re still male or female), the presence of intersex individuals, whose frequency is very low and no damaging to a binary view, and the fact that male seahorses can get “pregnant,” holding fertilized eggs in a pouch until they hatch (notice I say “male seahorses”, for these individual still produce only small, mobile gametes).

Because advocates of the “spectrum of sex” view are ideologues, who hold their position simply because they think the sex spectrum buttresses transsexual and nonbinary individuals, Richard’s talk here, or his essay in the book, won’t convince these opponents. (By the way, these people never tell us how we can define the sexes given that “sex is complicated.)  But if you’re open minded, have a listen, or better yet, buy the book, as the essay has a lot more than does the interview below. The universal and explanatory advantages of the UBD make it far superior to any other concept of biological sex.

h/t: Luke

In the short (4-minute) clip below from The Rubin Report, astrophysicist and science popularizer Neil deGrasse Tyson takes another point of view. Interviewed by Michael Shermer, Tyson gets all worked up on the topic of sports, finding it deeply weird that we split males and females when it comes to athletic competition. Two women, broadcaster Sage Steele and former swimmer Riley Gaines, weigh in on Tyson’s confusion.

Finally, below is the full interview of Tyson by Shermer. It’s on sex and race, and I’ve started it when they begin discussing sex (31:15).  You can see that Tyson apparently thinks from his astrophysical background that nature is structured against binaries, which he sees to consider an argument for the continuum of sex. He seems to deny, in fact, that there’s any value in discussing biological sex, and that gender is what’s important. (Remember Tyson’s famous “today I feel 80% female and 20% male” statement?)  As far as sports is concerned, Tyson suggest dividing sports up in to “hormone categories”, so people compete against others having with similar hormone ratios. (That’s problematic for several reasons, not the least being that people who take hormone supplements, like trans-identified males, may still have a strength advantage over biological women having a similar hormone titer, because the advantage is already there at puberty,  before most takes testosterone).

Then, pressed by Shermer, Tyson says that maybe we should use a combination of body weight and hormone titer. It’s a mess, which becomes simplified if you have three categories: “bioloigcal [natal] female,” “biological [natal] male,” and “other”. Alternatively, you might stipulate that anyone who is not clearly a biological female compete in the men’s class. (That too has problems, like a higher risk of injury for trans-identified females in competitive sports.)

At any rate, this discussion is really an add-on to the Dawkins video above, so listen if you have the time.