After a hiatus, Scientific American once again shows signs of wokeness, dissing the binary nature of biological sex

UPDATE:  Carole Hooven called my attention to a paper in Hormones and Behavior, on which Maney is co-author, which is far more explicit about the author’s motivation to depose the hegemony of binary sex.  Carole also tweeted about Maney’s paper:

“This species challenges the practice of flattening nature’s wondrous diversity into two categories, male and female.” White-throated Sparrows are indeed fascinating, challenging stereotypes about sex differences. I learned lots from your explanation of how that works.

But sex…

— Carole Hooven (@hoovlet) February 26, 2025

I had hoped and expected, after the departure of woke editor Laura Helmuth from Scientific American, that the magazine would go back to what it was good at and famous for: presenting solid articles on popular science actually written by scientists. The ideology-imbued science, I thought, would disappear, as readers were canceling their subscriptions.

Sadly, it appears that the magazine may well be creeping back to “progressive science,” at least as judged by the latest biology article I read, as well as a similar critique of binary sex and, as lagniappe, an op-ed promoting gender activism and “affirmative care”.

The good news is that the biology article presents some solid and interesting data on the white-throated sparrow, a bird with a unique system of genetics and mating behavior. The bad news is that the author, neuroscientist Donna Maney of Emory University, couches all her results, and those of her colleagues, as casting aspersions on the binary nature of sex. It’s the usual argument that “things are complicated here, and if we are blinded by the idea that sex is binary, we miss the complicated and interesting stuff.”  In other words, the biology presented is used partly to do down the sex binary.

Click to read (the article is archived here).

The article is long and complex (perhaps too complex for the non-biologist reader), but the phenomenon is quite interesting.  Here are the salient facts (wording is mine):

a.) The North American white-throated sparrow (Zonotrichia albicollis) comes in four varieties. There are two sexes (something the author admits but doesn’t emphasize), and each sex has two varieties that differ in color and behavior.

b.) Both males and females come in two flavors, and each sex has roughly 50% of each. Each morph behaves and looks the same whether it’s in males or females.  The “white” morph, shown on the left below, has a white stripe on its head, and, in both males and females, is more aggressive, defending its breeding territories more vigorously than do individuals of the tan morph (right below), which has a tan stripe and spends more of its time bringing food to the offspring.  The diagram below is from a paper by Romanov et al. in BMC Genomics.

c.) The genes for striping differences, as well as for the behavioral differences between morphs, reside on the birds’ second chromosome, and within an inverted section of that chromosome, where the chromosome has broken multiple times and been rearranged.  The white morphs have one copy of the rearranged chromosome and one of the “normal” chromosome, while the tan morphs have two copies of the “normal” chromosome. You can see the difference in the chromosome-2 photo at the bottom left above: in the white morph, the  copies of chromosome 2 are of different configuration because of the rearrangements.

d.) What happens if you get two copies of the rearranged chromosome containing the genes for aggression and white head color? Well, that doesn’t happen, and that’s the interesting part of the story. It turns out that white males will mate only with tan females, and tan males will mate only with white females.  Because of this, the white chromosome can occur only in a single copy.

Note also that, as far as the sexes are concerned, males have two copies of the “sex chromosome” and are ZZ, while females have unlike sex chromosomes and are ZW; this differs from the way sex is determined in humans and many other mammals. The Z and W chromosomes are, like our Xs and Ys, members of a pair, but they are not the second chromosome, which carries the genes for color and behavior. It is not unusual for genes involved in producing sex-specific traits to reside on chromosomes different from the sex chromosomes. Each male in humans, for example, carries genes for other sex-related traits like breasts and vaginas, but they aren’t expressed because they aren’t activated. Even genes involved in producing the human male vs. female reproductive system, like SOX9, DMRT1, NR5A1, and DHH, are spread throughout the genome.  We’ve long known this, and it’s not unexpected, but the author appears to think that this is an unexpected finding.

e.) Because there are two morphs of each sex, and each morph mates with a member of the opposite sex that has the opposite pattern and behavior, the system is stably maintained in this species.  How it evolved is another question, and the author implies it’s a mystery.  I can’t find any speculation about how the system arose in this species, but perhaps those speculations exists somewhere, and perhaps a reader/bird expert can help.  All I can say is now is that this system of sex-morph variability can maintain itself, and, also, the fact that there is an inversion on the second chromosome prevents gene exchange (that normally occurs during gamete formation) between the “normal” and “inverted” chromosomes. Crossing-over between inverted chromosomes, which leads to gene mixing between the two copies of each chromosome, leads to wonky chromosomes that cannot function. This prevention of gene mixing allows the two versions of the second chromosome to diverge evolutionarily and accumulate different genes, explaining why the color and behavioral differences we see reside largely on that chromosome.

There’s a lot more stuff in the article, and some good biology, but the data relevant to this post is above. The system is fascinating and somewhat of an evolutionary puzzle, though Maney and her colleagues are working out which genes are involved in color and behavioral differences, and how they result in differences between the morphs.

Note that there are only two sexes here, not four. Some benighted authors have said that this species has four sexes, but they are deluded. We have a case of two sexes and “polymorphism” (different behaviors and appearances) within each sex.  The author recognizes this, but, as you can see from the big-print heading below, she wants us to know that this system detracts from the importance of the sex binary:

The point is the usual one: “things are complicated here, and can’t be fully understood simply by recognizing that there are just two sexes.”  And that’s true, but nobody thinks that recognizing two sexes brings a stop to further research on any biological system. After all, work on this sparrow had to begin by recognizing that there are two sexes, and then realizing that each of the two sexes comes in two forms.  First, here are quotes showing that the author recognizes that there are two sexes. Bold headings are mine; the indented bits are quotes from Maney’s article:

Recognizing that there are two sexes, not four. Maney adopts the consensus definition of sex: males produce sperm in their testes and females eggs in their ovaries:

This interesting and complex situation has earned this species the nickname “the bird with four sexes.” But to be clear, White-throated Sparrows do not have four different types of gonads. As in other birds, each individual typically has either two testes that produce sperm or a single ovary that produces eggs.

, , , The sex chromosomes, which in birds are known as Z and W, influence whether primordial gonads develop as ovaries or testes. Birds with both the Z and the W typically develop an ovary, whereas birds with two copies of the Z develop testes.

. . . . Although color morphs in White-throated Sparrows are not technically sexes, the standard and supergene-bearing versions of chromosome 2 share features with the human sex chromosomes X and Y, respectively.

. . . . In White-throated Sparrows, we see “masculine” and “feminine” traits distributing themselves in a manner clearly orthogonal to gonadal sex. White-striped birds with ovaries behave in a way that is more masculine than we expect for female songbirds, and tan-striped birds with testes look and behave in a relatively feminine way.

So yes, the author admits that there are two sexes, with each having two varieties.

But despite that, she says that admitting the binary nature of sex somehow inhibits us from studying this system; it “flattens” the diversity.  So throughout her paper there are attempts to show that recognizing that there are two sexes somehow either inhibits research or stifles our interest in how this system evolves.  It does neither; this is pure ideologically-based attempts to do down the palpable fact, which the author recognizes, that there are only two sexes.  As I said, that recognition is the very beginning of an attempt to understand the multi-morph system, and I know of no biologist who would say, “Yes, there are two sexes here. That’s the truth, and we needn’t study anything else or ask further questions. And so we get to this:

Dissing of the sex binary. A few quotes from the author:

Nevertheless, as recent research has shown, this species has much to teach us about the nature of sex variability—the way in which sex-related behaviors are influenced by genes, the complex structure of sex-associated chromosomes and the evolution of sexual reproduction itself. Importantly, this species challenges the practice of flattening nature’s wondrous diversity into two categories, male and female.

Um. . .  well, the wondrous diversity is flattened into four categories: white males, white females, tan males, and tan females. But let’s pass on to more binary-dissing:

Even genes involved in gonadal development and hormone synthesis can be found on most any chromosome, mapping to locations throughout the genome that freely recombine. Each individual inherits a new combination of genetic and epigenetic material, resulting in diversity that defies binary categories.

We’ve known for years that sex-specific genes producing intraspecific or intra-sex variability don’t need to be on the sex chromosomes. There is no “defying binary categories” here.

A few more disses:

In most sexually reproducing species, making an embryo requires two gametes: one egg and one sperm. That binary is clear. But the egg-sperm binary does not apply to the eventual development of that embryo into a sexed body with sex-related behaviors. That development is conceptually separate and decidedly nonbinary in many ways.

This is the “development in sex is complicated, implying that the sex binary is simplistic” argument. Finally, there’s a Big Finish:

The development of sex-related traits is astonishingly diverse not only across species but within them. Every individual, sparrow or human, has masculine and feminine characteristics. That diversity is obscured when we lump individuals into two categories and consider each as a homogeneous group. When we compare the categories “female” and “male,” we often report a “sex difference”—a binary outcome made inevitable by a binary approach. This approach fails to acknowledge the profound overlap between sexes on almost any measure.

White-throated Sparrows help us see past the sex binary by forcing us to acknowledge sources of variability other than sex, which is, in reality, only a small contributor to variability for many species. Diversity and plasticity of phenotypic expression is the norm, particularly for traits that correlate with sex. Sex-related traits are simply not hardwired. Evolutionary biologists believe that this plasticity—like the dazzling diversity of sex-determining molecular pathways—may be adaptive in changing environments. Individuals retaining maximal flexibility in the expression of sex-related traits are better able to adapt quickly to changing environments or, in some cases, may even be able to change their sex.

I’m not sure what the author means by saying “every individual, sparrow or human, has masculine and feminine characteristics”.  Males and females do of course share common traits, like having (usually) five fingers and two legs, but inspection of myself this morning revealed neither a vagina nor breasts.  At any rate, the author is attacking a straw man here and throughout her paper. NOBODY argues that recognizing that there are two sexes in all plants and animals either stifles research or “flattens diversity”.

Once again, the recognition that there are just two sexes is the beginning of research to explain diversity.  This recognition, as Darwin realized, for example, gave rise to his explanation of why there is sexual dimorphism (differences in temperament, behavior and ornamentation between males and females). Hie explanation was sexual selection (Darwin saw two varieties, “combat” and “preference for beauty”). And sexual selection that is the direct result of females investing more in offspring than do males, something that starts with the different gametes.  Note that differences between animal sexes, which involve weapons like antlers, behavior like building bowers, or plumage and display traits, need not reside on the sex chromosome, and in fact cannot because there are simply too many differences between the sexes. The important part, though, is that this inter-sex and interspecific diversity can be understood ONLY as a result of the sex binary, which involves the ability to produce either high-investment eggs or lower-investment sperm.

I won’t go on except to say that perhaps we need a name for the tactic of doing down the sex binary (or pretending it doesn’t exist), by emphasizing both diversity of nature and the complication of sex determination and expression of sex-related traits. I will call it “The Argument from Complication” which says something like this:

“Nature, including the determination and expression of biological sex, is complicated and diverse.
Therefore the sex binary is relatively unimportant, because by itself it can’t explain everything.” 

I’m not sure why the author flaunted this straw man, and I have no idea who the new editor of the journal is. But what is clear is that either the author or the editor, or both, decided to slant what is otherwise an informative article towards criticizing the very important fact that there are two sexes in all plants and animals, and that the defining traits of those two sexes, involving gametes, is both universal and explanatory. If you want to read more about this, see this free article by Richard Dawkins.

Two additional notes. First, this article appears on the website, published yesterday (click to read; I just saw it and haven’t yet); it’s by our old friend Agustín Fuentes, who is making a living attacking the sex binary:

And there is this one, reporting a new study that seems to lack a control (click to read):

An excerpt from the Santora piece:

Suicide attempts among transgender and nonbinary youth jumped by as much as 72 percent from 2018 to 2022 in states that had recently passed laws to curtail their rights. And President Donald Trump took this onslaught to the federal level last month when he signed an executive order to cut federal medical care support for trans people aged 19 and younger, which two federal judges have since temporarily blocked. These political actions affect a set of young people who already had much higher rates of depression, anxiety, self-harm and suicide attempts than their nontransgender peers. Many of the recent state laws ban gender-affirming care—which a 2022 study suggests is a lifeline for many trans youth. In the study, those who received gender-affirming care had 60 percent lower odds of depression and 73 percent lower odds of suicidality over a 12-month follow-up than those who did not.

A growing body of evidence supports the mental health benefits of gender-affirming care for trans youth—including puberty blockers, hormone therapy and, in very rare cases, surgery. Now a new study adds to this evidence: it’s the first of its kind to show that hormone therapy improves overall emotional health among trans youth.

For the new study, published in January in the Journal of Adolescent Health, researchers tracked the emotional health of 315 trans youth aged 12 to 20 for two years after they began using hormone therapy (testosterone or estrogen). Emotional health is a component of mental health that concerns feelings; it shapes how we act in relationships, react to struggles and generally behave in everyday life. The study also tracked appearance congruence, a measure of how much a person’s physical presentation matches their gender identity.

Two points about it.  First, the “new study” doesn’t seem to have a control, so (and I just scanned it) the improvements in emotional health can’t be ascribed to hormone therapy. This is what controls are for! We know that gender dysphoria generally resolves and disappears in 80% of untreated children, so those controls are essential.

Second, the article does not mention the contradictory results in the literature, nor does it mention the famous but unpublished study of Johanna Olson-Kennedy that, over a period of two years (same as above) found contradictory results (the Olson-Kennedy study remains unpublished because the results weren’t ideologically acceptable!). From the NYT:

The doctor, Johanna Olson-Kennedy, began the study in 2015 as part of a broader, multimillion-dollar federal project on transgender youth. She and colleagues recruited 95 children from across the country and gave them puberty blockers, which stave off the permanent physical changes — like breasts or a deepening voice — that could exacerbate their gender distress, known as dysphoria.

The researchers followed the children for two years to see if the treatments improved their mental health. An older Dutch study had found that puberty blockers improved well-being, results that inspired clinics around the world to regularly prescribe the medications as part of what is now called gender-affirming care.

But the American trial did not find a similar trend, Dr. Olson-Kennedy said in a wide-ranging interview. Puberty blockers did not lead to mental health improvements, she said, most likely because the children were already doing well when the study began.

My conclusion from all this: Scientific American is, after a short hiatus, going woke again. Keep your eye on it.

h/t: Robert