Why Evolution is True is a blog written by Jerry Coyne, centered on evolution and biology but also dealing with diverse topics like politics, culture, and cats.
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.
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.”
(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).
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.
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.
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.
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 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 unanimouslythat 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.
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
“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.
If you have some good wildlife photos, please send them in. Thanks!
Today we have a text-and-photo tale by Athayde Tonhasca Júnior on his favorite topic: pollination, but also on sex and gender in plants. You should be impressed at the cleverness of plants in having evolved to facilitate reproduction through pollinators. Athayde’s narrative is indented, and you can enlarge the photos by clicking on them.
Nifty gender bias
Once upon a time in Ancient Greece, a young man was sauntering in the woods, enjoying the fine weather, unaware he was approaching a pond inhabited by the naiad Salmacis. Like all naiads, the minor deities that oversaw springs, wells and lakes, Salmacis had a weak spot for youthful, virile men. Awestruck by the lad’s beauty, Salmacis tried to seduce him. Her lascivious prattle only managed to alarm the visitor, so she pretended to give up and walked away. The young man, possibly flustered by the naiad’s unladylike harassment, decided to go for a dip in the pond. Beautiful he might have been, but not very smart: freshwater bodies were naiads’ territory. From behind a tree, Salmacis saw her chance. She leapt into the water to have another go at the shy looker, and the poet Ovid tells us what happened next: She poured herself all over the young man, and finally coiled herself right round him as he struggled against her and tried to slip out of her grasp. She was like a snake whom an eagle, the king of birds, snatches and holds up on high. (Metamorphoses, Book 4). Salmacis, who today would be on the Sex Offender Register, realised that her less than refined tactics were not working. In desperation, she begged the gods to let the two of them stay together forever. The gods complied, but interpreted the feisty naiad’s wishes literally. They merged Salmacis and her quarry in one body, creating a deity half man and half woman, with male and female parts. Perhaps an ironic destiny for a man whose name was also the product of a blend. A son of Hermes, the messenger of the gods, and Aphrodite, the goddess of love and beauty, the youth was called Hermaphroditus.
To 18th century naturalists, who were well versed in the Classics, Hermaphroditus was an ideal trope for a biological phenomenon known from ancient times: the existence of plants and animals with male and female reproductive organs. As biology progressed, the term ‘hermaphrodite’ began to be applied to sexually reproducing organisms that produce male and female gametes. Roughly 5% of all animals, mostly invertebrates, fulfill the condition. Among vertebrates, hermaphrodism is found only in some fishes and frogs: the great majority of species are gonochoric, that is, either male or female; the rare instances of hermaphroditism are considered pathologies.
Hermaphroditism may be unusual among animals, but it’s the way of life for most flowering plants. About 90% of them are functionally hermaphrodites, either by having male and female reproductive parts in the same flower or having male and female flowers in the same plant (these are known as monoecious). Hermaphroditism opens the door for self-fertilization, a handy strategy when mates or pollinators are rare or absent. But this type of shortcut in the dating game has severe disadvantages: it reduces genetic diversity, leading to lower capacity to survive and reproduce, and to adapt to changing environments. So it is not surprising that many hermaphroditic plants have developed physical and genetic barriers to avoid or reduce the possibility of self-fertilisation. Some species inhibit the germination of their own pollen grains; for others, their sex bits are morphologically different, such as long stamens and short styles or vice-versa (herkogamy); some resort to temporal separation of male and female stages (dichogamy).
If self-fertilisation was to be the norm among hermaphroditic plants, Charles Darwin’s evolutionary theory would be seriously dented because outcrossing (the interbreeding of unrelated individuals) sets the stage for adaptation by natural selection. Understandably, Darwin paid much attention to pollination mechanisms in his book about orchids (Darwin, 1862) that followed On the Origin of Species by Means of Natural Selection. His research and observations paid off: he closed his orchid book by stating it is hardly an exaggeration to say that Nature tells us, in the most emphatic manner, that she abhors perpetual self-fertilisation.
While investigating the ways orchids avoid self-fertilisation, Darwin discovered a particularly clever instance involving the autumn lady’s-tresses orchid (Spiranthes spiralis, then known as S. autumnalis), and bumble bees (Bombus spp.), its main pollinators. This orchid produces an erect, unbranched flowering stalk, 7-20 cm tall. Flowers bloom from the bottom of the stalk to the top and are protandrous, a form of dichogamy where male reproductive organs mature before the female ones (studying botany is a sure way to improve your Scrabble scores). These traits are important for what Darwin observed in relation to the behaviour of visiting ‘humble bees’. In his own words: The bees always alighted at the bottom of the spike, and, crawling spirally up it, sucked one flower after the other. I believe humble-bees generally act thus when visiting a dense spike of flowers, as it is most convenient for them; in the same manner as a woodpecker always climbs up a tree in search of insects. This seems a most insignificant observation; but see the result. The result is thus: a bee alighting on the lowest flowers and making her way up may pick up some pollinia (sticky blobs of pollen grains typical of orchids) that may get transferred to apical flowers. However, this pollen will be wasted because upper flowers are functionally male; their pollen is ready to be taken away but their female parts are not yet mature. Bees that gather pollen from apical flowers fly away to the bottom of another stalk, where flowers are older and therefore receptive (functionally female). Thus, cross-fertilisation is assured. This setting has been labelled Darwin’s inflorescence configuration, a fitting tribute to his skills in observation, experimentation and deduction.
Like the autumn lady’s-tresses, the rosebay willowherb (Chamaenerion angustifolium) is hermaphroditic, protandrous, has an inflorescence that blooms from bottom to top, and is pollinated by bees, mostly Western honey bees (Apis mellifera) and bumble bees. Rosebay willowherb too takes advantage of bees’ stereotypical foraging behaviour of moving up along erect inflorescences, but it goes one step further to encourage visitors to follow the script: flowers at the bottom of the inflorescence produce about 1.4 times more nectar than apical flowers (Antoń et al., 2017). Many bees and other pollinators visit flowers sequentially from the highest to the lowest quality, and stop inspecting those below a threshold (Carlson & Harms, 2006). This foraging strategy works to a T for the rosebay willowherb: a bee starts at the bottom where nectar is best, makes her way to less rewarding but pollen-bearing apical flowers, then flies away, hopefully taking some pollinia along.
Functionally female or male flowers secreting more nectar than their counterparts is known as gender-biased nectar production. This phenomenon is relatively uncommon (although data are limited) but has been reported for a range of unrelated species, which suggests it evolved independently several times. Most known examples consist of biases towards functionally female flowers, just like the rosebay willowherb, and in most cases Darwin’s inflorescence configuration and bee pollination are involved (Strelin et al., 2025). We don’t know for sure whether gender-biased nectar production increases the probability of pollen transfer and promotes outcrossing, but it’s a reasonable assumption.
Charles Darwin considered himself a mediocre botanist, even though eight of the ten books he published after On the Origin were about various aspects of plant biology, particularly reproduction (Barrett, 2010). The great naturalist was fascinated by flowers’ ‘beautiful contrivances’ that assured outcrossing and avoided the traps of inbreeding. When we look at the pas de deux performed by the autumn lady’s-tresses and rosebay willowherb with their pollinating bees to keep their hermaphrodite flowers on the straight and narrow towards cross-fertilisation, we can’t help but share Darwin’s fascination.
As everyone knows, I adhere to the gametic definition of sex, in which individuals are classified as male or female (or, as in hermaphroditic plants, both sexes in one individual) based on whether their bodies are set up to produce small, mobile gametes (the “males”) or large, immobile gametes (the “females”). I’ve explained why I adhere to this definition, because it is not only universal in animals and vascular plants, but also because the difference between males and females in investment in gametes, which leads in general to females having a greater overall investment in reproduction, explains a lot of puzzles in evolution. One of them is why sexual selection creates males and females who are often so different in color, size, weaponry, and so on. Just remember: universality and utility.
Here’s a more formal definition given by Colin Wright write in his new post on his website, Reality’s Last Stand.
In biology, the definition of male and female has never been arbitrary or culturally relative. It is grounded in the concept of anisogamy: the existence of two distinct types of gametes—sperm and ova. This fundamental reproductive asymmetry defines the two sexes across all sexually reproducing anisogamous species. An individual that has the function to produce small, motile gametes (sperm) is male; one that has the function to produce large, immobile gametes (ova) is female. This is not a social construct or a philosophical preference—it is a basic principle of evolutionary biology, established long before today’s cultural debates.
Now of course this definition wasn’t pulled out of thin air: it is an a posterioriconclusion about how nature is set up. It is a truth that all animals and vascular plants have only two sexes, male and female, though in some species, as I said, individuals can be of both sexes. (And some individuals, like clownfish, can change their gametic sex.) But there is no third sex, no matter how hard the ideologues squeal about seahorses, clownfish, and hyenas. There is no third type of gamete in any species. In fact, the opposition to the binary nature of sex by gender ideologues have led some of them to argue that the gametic definition of sex is a recent confection sneakily devised by “transphobic” biologists who want to shoehorn all people (and animals and plants, apparently) into two categories. Colin wrote the piece below to show that this claim is false. The gametic definition has been around for about 140 years.
Click on the screenshot below to read the piece (Colin’s bolding).
Now I make no claim that the gametic definition of sex is universal among evolutionary biologists, much less all biologists. I haven’t taken a poll! But the biologists I’ve encountered in my own field almost universally adhere to that definition. At any rate, Colin goes way back in the past to show a passel of biologists (I know many of the more recent ones) who adhere to and have presented the gametic definition of sex. As Colin says:
The historical and scientific record is clear: from the 19th century to the present day, biologists, medical professionals, philosophers of science, and evolutionary theorists have used gamete type as the defining criterion for sex. This document compiles citations from that record, providing a reference point for students, scientists, educators, and anyone interested in understanding what “male” and “female” mean in biological terms.
These citations span more than a century of scientific literature, showing that the gamete-based definition of sex is not a recent invention or a reactionary response, but a longstanding, fundamental biological principle. While sex roles and secondary sex characteristics can vary, the definition of the sexes does not: male and female are reproductive categories rooted in the type of gamete an individual has the function to produce.
This document is a work in progress. If you are aware of additional scholarly references—especially historical ones—that clearly depict the gametic definition of sex, please share them in the comments so I can continue to expand and improve this resource. I encourage readers to bookmark this page and return to it often as a reference in conversations, research, and advocacy.]]
I think I sent him the Futuyma reference (not below), but I can’t remember. At any rate, you can read them all yourself, but I’ll put up five of them spaced apart, starting with the first one in 1888. These are from Colin’s piece:
1888 – Charles Sedgwick Minot. “Sex,” in A Reference Handbook of the Medical Sciences Embracing the Entire Range of Scientific and Practical Medicine and Allied Science, Vol. 6, Alfred H. Buck (ed.) (New York: William Wood and Company), 436-438
As evolution continued hermaphroditism was replaced by a new differentiation, in consequence of which the individuals of a species were, some, capable of producing ova only; others of producing spermatozoa only. Individuals of the former kind we call females, of the latter males, and they are said to have sex.
1929 – Horatio Hackett Newman. Outlines of General Zoölogy (New York, The Macmillan Company), p. 448.
Any individual, then, is sexual if it produces gametes—ova or spermatozoa, or their equivalents. Thus we would be justified in calling any individual that produces ova a female, and one that produces spermatozoa a male. One that produces both kinds of gametes is a male-female or, more technically, a HERMAPHRODITE. Thus we may say that the PRIMARY SEXUAL CHARACTERS of individuals are the ova or the spermatozoa, and that maleness or femaleness is determined by the possession of one or other of these two types of gametes.
A ringer: Simone de Beauvoir!
1949– de Beauvoir, Simone. The Second Sex, translated by H.M. Parshley (New York: Vintage Books), 39
In the vast majority of species male and female individuals co-operate in reproduction. They are defined primarily as male and female by the gametes which they produce—sperms and eggs respectively.
2013 – Roughgarden, Joan. Evolution’s Rainbow: Diversity, Gender, and Sexuality in Nature and People. University of California Press. [Note: Roughgarden is a trans-identifying male]
To a biologist, “male” means making small gametes and “female” means making large gametes. Period! By definition, the smaller of the two gametes is called a sperm, and the larger an egg. Beyond gamete size, biologists don’t recognize any other universal difference between male and female.
2021 – Bhargava, Aditi, et al. “Considering sex as a biological variable in basic and clinical studies: an endocrine society scientific statement.” Endocrine Reviews 42.3: 219-258.
The classical biological definition of the 2 sexes is that females have ovaries and make larger female gametes (eggs), whereas males have testes and make smaller male gametes (sperm); the 2 gametes fertilize to form the zygote, which has the potential to become a new individual. The advantage of this simple definition is first that it can be applied universally to any species of sexually reproducing organism. Second, it is a bedrock concept of evolution, because selection of traits may differ in the 2 sexes. Thirdly, the definition can be extended to the ovaries and testes, and in this way the categories—female and male—can be applied also to individuals who have gonads but do not make gametes.
So much for those chowderheads who say that, using the gametic definition, neither a pre-puberty human, a postmenopausal woman, or a sterile person can be male or female. If you see this argument, you know you’re dealing with someone who’s intellectually dishonest.
Again, this is not a vote to see how many biologists (or feminists!) would define biological sex. It is meant, as Colin said, to show that the gametic definition of sex has been around for well over a hundred years.
