Dr. Hooven (“Carole” to me) has a new piece in Tablet (click headline below to read for free) explaining why all sensible biologists see sex as a binary defined by two (and only two) types of gametes. Perhaps you’ll already be familiar with some of her arguments in the article below (click to read), as I’ve written extensively on the topic. But she adds some good angles in the piece, which she ties together by reporting how she was forced to leave Harvard because her department couldn’t abide her teaching that sex was binary (see her story here).
The impetus for the Tablet piece begins with Agustín Fuentes’s recent book Sex is a Spectrum: The Biological Limits of the Binary, a book that is ideologically rather than scientifically based (see my own short review here and another critical review here). It’s simply a bad and misleading book. And, like so many other people denying the binary nature of sex, Fuentes is motivated not by any new scientific developments effacing the binary, by rather by ideology: if he and others are able to say biological sex is not a binary but a spectrum, it supposedly gives succor to those who don’t identify themselves as “male” or “female”. This motivation becomes clear in Fuentes’s last chapter. (Please note that the concept of “transsexual” implicitly assumes a sex binary, as there are only two ways to transition.)
Carole was inspired to write her piece, however, by a positive review of Fuentes’s book in Lancet, written by Sarah Richardson—a Professor of the History of Science and Professor of Studies of Women, Gender, and Sexuality at Harvard, as well as director of the Harvard GenderSci Lab. She was a colleague of Hooven but they have clearly parted intellectual ways. (See my take on Richardson’s piece here,). Richardson’s review, also attacking the binary, is not only ideological, but also mean-spirited, attacking the motives of those who tout the sex binary. (See below.) My report on Richardson’s misguided piece gives a screenshot of her review as well as some of Carole’s tweets that gave rise to her Tablet piece.
As Carole says in her new piece, Richardson prefers to attack the binary people (we can call ourselves “anisogamists”) on ideological rather than scientific grounds. We are, Richardson avers, motivated by a desire to erase trans and nonbinary people. That is dumb; none of us want to do that!
A quote from Hooven in Tablet:
Richardson not only thinks the “gametic” definition of sex is wrong; she also insists that its adherents have sinister political motives:
Although the gametic definition makes reference to biological systems, it is sophistry, not science. Those who promote this definition favour the assertion that sex inheres in gamete (sperm and egg) production because, in part, it facilitates their political aims by fuelling unhinged panic in some quarters about transgender threats to traditional gender roles. … Like scientific bigots of yore … the recent favour bestowed on [this] definition of sex … appeals selectively to science to naturalise and rationalise inequality and exclusion.
Richardson goes on to praise Fuentes for recognizing scientists’ “responsibility to respond to harmful deployments of inaccurate, overly simplistic, and reductionist science by those attempting to naturalise and depoliticise their hateful views.”
This is intellectually dishonest in the sense that many anisogamists, including me, favor trans rights (though they are limited in a few respects, involving things like sports participation and prisons). It’s even more dishonest in that previously Richardson herself had promoted the sex binary. To wit: a tweet from philosopher Tomás Bogrdus, followed by the first of four critical tweets by Hooven:
It gets more awkward for Richardson. In this 2025 review, Richardson says the gametic view of the sexes is sophistry, and those who promote it are motivated partly by bigotry.
Buuuuut in her own 2013 book, Sex Itself, Richardson seems to promote the gametic view. See attached. https://t.co/IxpFAGwVrb pic.twitter.com/xu8YsOUKbd
— Tomas Bogardus (@TomasBogardus) August 6, 2025
Since there have been no important advances in sex concepts based on science in the last 12 years, we can hypothesize that Richardson changed her views on the binary to conform to the Zeitgeist: in this case to the rapid increase of people who see themselves as nonbinary, and whose self-identification must be considered sacred.
Now Carole is extremely nice and her Tablet piece, while pointing out the misguided rancor of Richardson, is itself perfectly polite, sticking to the facts. One thing I like about it is how she introduces the binary, not simply by asserting the universality of only one distinction between males and females (gamete type) or of the utility of a binary concept (see Dawkins’s piece here for that), but through the act of sexual reproduction itself. This then naturally segues into the gamete binary. The bolding in Carole’s excerpt below is mine.
The question of how to define sex is not a new one, but the answer has taken on new urgency, given its implications for areas such as law, public safety, healthcare and sports. Despite the urgency, the correct answer has been understood since the late 19th century.
It might be helpful to think about the act of sex, perhaps in nonhuman species like chickadees or chacma Baboons. In sexually reproducing organisms (the overwhelming majority of animal species), while sex often satisfies a deep drive and is generally enjoyable, enjoyment is not the primary purpose of sex; it is instead a strong motivator, natural selection’s solution to get animals to engage in an often-risky behavior that requires a significant expenditure of energy. The primary purpose of sex is to produce offspring that combine the genetic material of their parents, so that those offspring can go on to pass on their DNA to future generations, and so on.
Moreover, sexual reproduction in animals can only occur when two distinct types of gametes (specialized sex cells containing DNA) fuse: the small mobile ones (sperm) and the large immobile ones (eggs). We call animals that produce sperm “male” and those that produce eggs “female.” That’s about it. The bottom line is that there are two gamete types and thus two sexes. There are no other sexes, no other reproductive categories.
Among mainstream evolutionary biologists, there is simply no disagreement on these basic points: The “gametic view” is the established orthodoxy of our field. It applies across sexually reproducing animals and accommodates all the complexity and variation within the sexes. It holds in nonreproductively viable animals—like postmenopausal me—that don’t produce gametes; it holds in male seahorses that get pregnant; in clownfish who change from male to female (first producing sperm and then eggs); in females who identify as male (trans men) and take male levels of testosterone and have a deep voice and a thick, bushy beard.
There are no additional or intermediate gametes. There are only sperm and eggs. Therefore, there are only two sexes, even if some people (or other animals) don’t fit obviously or neatly into one sex or the other. Traits associated with sex—like chromosomes, hormones, brain, feelings, or behavior—are not binary; nor do they define sex. However, there are two, and only two, sexes.
Hooven herself segues into the implications for science education, and mentions Harvard’s “kick in the pants” by the Trump Administration:
What happens on campus and in scientific journals carries tremendous influence beyond the academy. So when those institutions promote this kind of pseudo-debate and name-calling over consensus science, knowledge is subordinated to political goals. When a prestigious university signals that a scientifically grounded view is socially radioactive, that framing leaks into the wider culture—into media, politics, and policy. Soon, an orthodox fact becomes unsayable in polite company, making it harder to have good-faith public debates and contributing to political extremism.
. . . Harvard has made some meaningful and positive changes that are designed to increase viewpoint diversity, including the abolition of mandatory DEI statements in hiring and the adoption of an institutional neutrality policy, which prohibits the administration (from department chairs to the president) from issuing public statements on issues not directly relevant to the core mission of the university. More recently, under pressure from the federal government, DEI offices have been rebranded, statements about the importance of viewpoint diversity have been issued, and committees established to investigate and report on other problems with campus culture (most concerning bias on campus in the wake of Oct. 7). While these changes are positive, they should not have been necessary, nor should extreme external duress have been required to prompt them.
It’s unfortunate that Harvard’s kick in the pants had to come from the federal government. The punishments levied, including a freeze on more than $2 billion of research grants, may be illegal and vastly out of proportion and will likely do more harm than good. So while Harvard is right to fight back, it would be wrong not to use this as an opportunity to make substantive changes.
Apparently Tablet approached Carole to turn her Twitter posts into this article.
You can read the rest for yourself, but she told me to pay special attention to the video in the second link below. I’ve put the video below to save your having to click (the link is in a discussion of Richardson’s position at Harvard):
[Richardson] is also the head of Harvard’s GenderSci Lab, whose work aims to “counter bias and hype in sex difference research, elevate the importance of context, contingency, and variation in the study of gender and sex in biology … and engage the implications of biological claims about gender and sexual diversity for law and public policy relevant to the lives of gender and sexual minorities.“
The YouTube notes on the video describe it this way (you can read more about Lett here):
Sarah Richardson, PhD, Director of the GenderSci Lab at Harvard University and Elle Lett, PhD, discuss what there is to be hopeful about in the science of gender and science in early 2025 at an Intersectionality Research Salon.
Note that Lett praises Richardson for helping “craft the world we want to see. . . through science.” And Richardson makes no bones about using her work to put out “messages” that, to me, are apparently “progressive” messages. One senses not a motivation to seek the truth, but to buttress those seen as oppressed.
You can of course use science to better the world in a direction that you want. Innovations in medicine, like mRNA vaccines, is one example. But what you can’t do, and what Richardson and Fuentes are trying to do, is to bend science out of shape, pretending that it conforms to and buttresses a particular ideology. (This is what I call “the reverse naturalistic fallacy”.)
Not only do Fuentes and Richardson twist the science, but their harmful activities extend to mischaracterizing their opponents as bigoted transphobes. That, they must surely know, is wrong. But when you can’t attack your opponents’ facts, you can always attack their motives.
Now it hasn’t escaped my notice that I myself characterize Richardson’s and Fuentes’s motives, but they’ve been pretty transparent about them. And besides, we have the facts on our side, facts I’ve adduced many times. Sex is binary.
I’ve asked ‘sex is a spectrum’ people to explain how a 60% male person reproduces. Does he need to find a 60% female person and how can they recognize each other? They never answer.
One of my (many) pre Musk twitter bans was for telling a woman with a ‘nonbinary’ child that the child would know exactly which sex it would need to find to breed.
Every adult knows their sex, even if they pretend they don’t. Those who still have difficulty with it need therapy. An example of that being India Willoughby. He insists he literally became a woman by transitioning. He claims to have a cervix and presumably he doesn’t attend his free prostate checks. He is severely delusional and needs serious help.
I couldn’t agree more. I wish pronouns weren’t included in bios, in emails, or on name tags. There is no “they/them”. And if I’m forced to accept this, then I have to use a subject-verb mismatch: “This is a very nice person.”
I stick with standard English and will not let anyone compel my language. I’m in the fortunate position of not having to worry about employment, so I can be as curmudgeonly as I like.
Several high profile people who supported TRAs are now removing pronouns from their bios, eg Sadiq Khan, Mayor of London.
Then again, there are idiots like actress Lynda Carter who removed her role as Wonderwoman from her X bio after complaints from TRAs, although I suspect it may actually have been gender criticals trying to wind her up 😂
If a research university is like a human body, with the various departments analogous to different parts of the body, then wokeness seems to be an infection of some part of that body.
Many venerable institutions suffer this infection. It seems very resistant to treatment and gangrene is setting in. To save the rest of the body, the affected part may need to be amputated…
More cancer than contagion.
This is typical of the Progressives. They try to introduce new standards and, when people react by defending the existing standards, they cry foul and imply that the reaction is in itself innovation.
The ad hominem fallacy is as old as the hills, and it appears to be core to Ms. Richardson’s critique. When you’ve been reduced to attacking the messenger, you’ve already lost and you know it.
My wife and I read this piece by Carole Hooven last night. Glad to see you highlight it here.
Her book, along with Alex Byrne’s arrived in my mail this week. I had put them both off, my book reading never keeps up with my buying. But then I saw Alex Byrne’s recent commentary “How Many Sexes? How Many Genders?” in the Archives of Sexual Behavior. It should win a prize for getting straight to the point. Here is part one:
How Many Sexes?
Two (Parker, 2011).
I went straight to Amazon and ordered his book! But then I thought, my wife will never read this, but I bet she’ll read the other one. So, I bought Carole’s, too. Is that a man thing to do?
https://link.springer.com/article/10.1007/s10508-025-03209-z
It would make discourse easier if everyone would simply agree to use the separate words “sex” and “gender” for their separate meanings. Somehow decades ago people decided to use “gender” as a synonym for “sex” and now the gender pushers deliberately exploit the ambiguity to confuse things.
Personally I don’t use the word “gender” much. Its meaning is slippery and vague and seems to change a bit every few years. Depending on context, “gender”might refer to one’s psychological self-perception of maleness or femaleness, or it might refer to arbitrary socially constructed roles and expectations, or it might mean whatever the speaker imagines it to mean.
By contrast, “sex” is, or rather should be, a clear unambiguous word. In a scientific context, it is absurd to use the word “sex” in anything other than its traditional meaning which is a matter of reproductive function and structures. And it is silly to say “gender” when one means “sex”. It annoys me if I hear a biologist speak of the reproductive behavior of salamanders and the person says “gender” to refer to the male-female differences of the creatures. In my dialect of English, it is absurd to say that a salamander has a gender. Sex is obviously the right word here.
Either gender is equivalent to sex, or it’s as meaningless as “soul”. Unmeasurable, completely subjective, and useless for any purpose except argument.
Indeed, “gender” is most commonly used today essentially with reference to what we use to call “personality traits”.
Reminds me of an old episode of Happy Days in which the Fonz grows to accept the fact that his nephew (or maybe he was a cousin) likes flowers more than motorcycles and wants to open up a flower shop. Today he would probably be guided on to the road to transitioning.
Your understanding of the history of the word ‘gender’ is wrong. It has been synonymous with ‘sex’ since the Middle Ages. It wasn’t until the late twentieth century that some academics decided to use the word to mean “sex roles” or “gender identity”. In everyday.speech, ‘gender’ and ‘sex’ were synonymous.
The problem is that these academics and the trans rights activists are dishonest and equivocate between the normal meaning of the word ‘gender’ and the meaning that they want to assign to it. The solution is to use the word properly, as a synonym for ‘sex’, because that is what is at issue here. Men and women aren’t made to use separate locker rooms and showers because of the social roles they play or their feelings about their identity, they’re separated from each other because the men have penises and the women have vaginas and if you let humans with penises use the same showers as humans with vaginas, there’s going to be trouble.
A number of years ago, I had been susceptible to the “sex is a spectrum” argument, infused with examples of intersex human conditions which would show that simple models can’t capture the true complexity of the world. Carole Hooven’s writing played no small part in laying out for me the sex binary, which I’m of course completely on board with now.
But as important as the gametic definition is for understanding evolution, I also have come to think that it can’t be the only consideration in any question of society. Principally, it seems clear to me that in the gametic definition, 46XY-CAIS individuals have to be classified as male–they have typically undescended and atrophied testes, and no ovaries–yet there is no aspect of society in which it would be proper to treat them as male. Not athletic participation, not changing room access, not restrooms.
I’ve read the piece The Paradox Institute has in which they call this “sex reversal,” but I don’t find it convincing–it’s an epicycle, trying to force the biological definition to work for questions in society.
(My answers to the questions of society: athletic participation should depend on an androgenizing adolescence; women’s changing rooms should be, essentially, penis-free zones; restrooms–where you never see another person naked to begin with–should be about presentation.)
Hi Tom,
Thanks for your thoughtful comment — and it’s so nice to know that something in my work helped clarify the issue of the sex binary. I wanted to address 46,XY CAIS (complete androgen insensitivity syndrome), which I write about at length in my book T.
Since many readers won’t know what this is, here’s an overview: CAIS is a difference of sexual development, or “DSD.” Almost all people with this condition look and feel completely female, and are sexually attracted to males. Many don’t know they are different from other girls in any way until adolescence, when they fail to menstruate and discover they have XY chromosomes and internal testes.
These individuals start down the male pathway in utero, with XY chromosomes and normal testes that produce testosterone. But because their androgen receptor is nonfunctional, the body cannot respond to (“hear”) the testosterone. The child is born with what looks like a typical vagina (but no cervix, uterus, or ovaries). Unless genetic testing is done, these babies are sexed and raised as girls. At puberty they develop female-typical traits—breasts, hips, fat distribution—though usually without acne or much body hair.
On the strict gametic definition they’d be classified as male, but that makes little sense socially or legally, since the effects of testosterone, or the lack thereof at critical stages are so important for social sex categorization. So I agree that in all areas, they should be treated as female, including sports, locker rooms, bathrooms, etc.
As far as transwomen accessing female sports and bathrooms, those are tougher issues. Some evidence suggests that the high testosterone in early male development may confer athletic advantages, even in males who transition before puberty. (Boys play rougher than girls, even though they have similar testosterone levels…it’s due to permanent effects of high T in males in utero, which may also have permanent physical effects.) But here the evidence for actual outcomes in such adults is weak, and we need more research. So, perhaps we should go with your view until we know more, though some argue the female category should be protected until then.
With bathrooms/locker rooms, lots of women just don’t want males in them, regardless of how they identify, how they look, or what genitalia they have. Bathrooms are kind of a special place for women, to change, do makeup, deal with periods, talk about men, etc. And without men in them, they are relatively clean! At the same time, it must be exceedingly difficult for transwomen use the men’s room (same goes for transmen in the women’s room!). So it’s not easy, but I lean toward letting women decide whether to open up female spaces to males, since many males are still bigger and stronger and have had a lifetime of testosterone exposure. That can feel threatening for many women.
Sorry for the long response, it’s just that you raised the issue of how difficult it is to cleanly separate biology from social policy. I just hope that we can have clarity about which is which, and the freedom to get the facts out there so we can have discussions like these about policy.
By “trans women”, are you referring to men who have surgically modified their appearance – including having genitals removed ? If so, I can see why they may face difficulties using the men’s restroom.
But from what I know, the vast majority of “trans women” are simply men in dresses cosplaying as women – a consequence of “Self-ID is all you need.” They should be using the men’s room, right ?
Only around 5% of trans identifying men go through surgery. The vast majority have no intention of having their penis removed. Most are autogynephiles, ie fetishists who are turned on by the idea of seeing themselves as a woman. They are the ones who are desperate to access women’s spaces as it ‘validates’ them. They are narcissists and many publish photographs of themselves in women’s spaces, sometimes while exposing themselves, and they keep asking if they ‘pass’. As you say, they are the cosplayers. By accessing women’s spaces and crossing our boundaries, it also shows they are predators.
There are many ‘old school’ trans identifying men. They respect women and use the gents. One told me that he gets ‘funny looks’ in the gents, but he gets a lot worse in the street, so it doesn’t bother him. Many are trying to reclaim the word ‘transexual’ to separate themselves from the lunatic TRA mob.
Statistically, more men have been assaulted in women’s spaces than in men’s. Trans identified men are safer in the gents but TRAs don’t care because they need the ‘validation’ of being seen in women’s spaces. That is also why they fight against having a third space.
I get where you’re coming from wrt inclusion and kindness to people with DSDs. So agree with you. But I’m not sure where you’re going wrt 46XY-CAIS. The population frequency of individuals with that DSD who have breasts and an externally normal vulva and other secondary sex traits typical of females but with undescended and undetectable testes (by definition male) is ~0.00001 (the total frequency of all 46XY-CAIS individuals may be higher, but many have obviously unusual genitalia or other male secondary sex traits that indicate they are males). Those folks are vastly outnumbered by genetically and phenotypically normal males who adopt a queer gender identity and insist they have changed sex for the purpose of access to women’s sport, bathrooms, changing rooms, prisons, shelters, dating apps, scholarships, and jobs. I think the first urgent task is to modify social policy to deal with that threat to the sex-based rights of women and girls. I think your answers to the questions of society are potentially ok except wrt presentation (men just need to get used to feminine males in the men’s restroom). After righting the ship along those lines we could find some compromises wrt rare people with DSDs.
[argh posted at the same time as the detailed & thoughtful reply from Dr. Hooven]
46,XY CAIS might be a theoretical conundrum to scientists, the legal system, and society in general as to whether affected persons are “really” male or “really” female. But the problem solves itself. Even if the law said a person diagnosed (typically at 15 or so, as Carole Hooven explains) was legally male and must ensure all documents say so and use only bathrooms etc. that reflect his true male sex, the law would have no way to enforce this. It could not determine except by medical testing which typical female-appearing people were women, and which (a tiny minority) were deemed to be men (with CAIS.) In reality, a person diagnosed with CAIS after 15 years of being a girl would simply carry on as a woman and not change any documents or out herself out as a man. No one in the whole wide world (except her doctor, who can’t blab) need ever know she had testes and a Y chromosome and was living in non-compliance with the law. Problems that solve themselves aren’t problems.
Sex testing for sporting competition would disclose her male sex but CAIS is well-known to sport governing bodies and a waiver would be granted without fuss. Important here is that the sporting body would respect the confidentiality of her medical information and would never out her. She would present as just another competitor who had passed the sex testing and anti-doping rules in place to uphold the integrity of her sport. The sport authorities world would never tell the world she had an Y chromosome and was “technically male” but was being allowed to compete “as a woman”. There would be nothing about her nude body in the locker room (or her punch in the ring) that would tempt suspicion and rumours.
I am less sympathetic to Dr. Hooven’s worry that “transwomen” would be afraid of using a men’s restroom while wearing a dress and makeup. If they are, this is not a problem women have to solve for them by accommodating their proclivities. “Transwomen” are men. Choices have consequences.
The blank slate hypothesis applied to the world? Science does not and cannot change reality, rather, it works the other way around.
If one day I put on a dress and bright red lipstick (not that I’ve ever done that), I will have changed my “gender” (learned culture-specific sex stereotypes) but not my sex, which remains male and cannot be changed. At least that is how I understand the difference between gender and sex.
Yes, that is still exactly what everyone knows to be true, except for the wokes. I suspect even the wokes know this to be true – they are just posturing for virtue points.
The sex-is-a-spectrum partisans never share with us their perspective on crashingly obvious phenomena downstream of the gametic binary: embryonic/fetal development and birth. Do spectralists suppose that some members of the next generation develop in one gender, some in the other, and some in a different place entirely on the “spectrum”?
In mammals, the binary distinction and the unique role of the maternal parent has a lot to do with behaviors, and with the survival chances of the young after birth as well. Who knows, this might even have some corollaries in that primate species in which there are foraging strategies called professor of sociology, professor of critical gender studies, and etc. .
A striking fact is that every one our ancestors, since the beginning of our species, was clearly a male—with testis and a penis—or clearly a female—with ovaries and a vagina. Not a single exception. And the binary is not just in the gametes, but in the whole reproductive apparatus. This means that a person that declares herself/himself “nonbinary”, is the first one in her/his entire genealogy.
Nothing is true until it appears in a peer-reviewed journal. We can safely discard the so-called knowledge of those past.
I do have to admit being amused when I read people who write things like, “We have known what sex is since the 19th century.” Yes, I know what they mean, but it still makes me chuckle.
Testes, penis and vagina, yes, recognized since the beginning of our species (or even earlier). Ovaries, well, these were first recognized as belonging to the reproductive apparatus by the ancient Greek anatomists, at least as far as is recorded. And more widespread (and more exact) knowledge of their existence and function came much later.
This recent summary paper is well worth a read:
https://labs.la.utexas.edu/buss/files/2025/09/There-Are-Only-Two-Sexes-and-There-Can-Never-Be-More-Dougan-2025.pdf
Very helpful, succinct summary, thanks.
Hi Jared; One can also read the history of Geoff Parker’s 2 seminal papers from 50+ years ago, in his own words.
https://www.mdpi.com/2073-4409/10/2/287
eric
the recent favour bestowed on [this] definition of sex [gametic] … appeals selectively to science to naturalise and rationalise inequality and exclusion.
This is untrue in more ways than one.
Anybody who has bothered to acquaint themselves with gender critical arguments and the people making them will know that the arguments are not made in defense of rigid sex roles or traditional inequalities, and many gender critics are themselves sex-nonconforming. (Paging Mr. Menno!)
But, less obviously, it’s ultimately the genderists who unwittingly support traditional sex roles and inequalities. Gender identity theory posits “gender identity,” a vague and unfalsifiable notion, but all transition realistically comes down to is the adoption of (at least some) cross-sex norms. Saying “If you behave, or enjoy behaving, the way women are expected to behave, you’re a woman” is not a brave statement in favor of human freedom from sex stereotypes. In fact, it’s the exact opposite. You’re making those stereotypes central to your “identity” and defining manhood and womanhood by them.
Is this true: “there are two gamete types and thus two sexes?” What about XXY? and XXXY? Don’t these >46 sometimes express female (outwardly) but mostly male? Why are these not-that-infrequents relevant?
Because anyone with a Y chromosome can produce only spermatozoa or no spermatozoa, never ova, and never any internal female structures. They are unmistakably boys and their spermatozoa are completely typical (if they make any at all — many don’t, even though they have the organs to do so.) No “spergs”, as Colin Wight puts it. The more X chromosomes the affected boy has, the more deleterious handicaps he tends to have, particularly mental retardation. But he’s still male-looking. (This isn’t a knock against women. Most children with abnormal numbers of any chromosome will have lower intelligence, along with many other health problems.)
SRY can be thought of as dominant over all the female-making genes on the X chromosome. No matter how many X’s you have, one Y makes you male. All those Mullerian genes go silent once SRY speaks. Even if you don’t have a functioning testosterone receptor, SRY still commits you to male differentiation as far as it can get without androgen effect, to a testis at least,….and abolishes female differentiation.
“The SRY gene (Sex-determining Region Y) encodes a protein known as the sex-determining region Y protein, which acts as a transcription factor. This protein is essential for initiating the development of male gonads (testes) during embryonic development. When the SRY gene is expressed, it triggers a cascade of molecular events that lead to the differentiation of the undifferentiated gonads into testes, preventing the development of female reproductive structures.” -Bing; posted ‘cuz I’m learning and so others may. Looks like I got my answer; thanks!