Sexual reproduction certainly does involve more than just the gametes themselves, but the definition of sex is based on gametes - and that they comprise two distinct classes of cell, in size and form. Otherwise, in gonochoric species, how would anyone know which sex characteristics are female and which are male, and how the female and male sex development pathways differ? And in hermaphroditic species, which anatomical and cellular structures correspond to the female and male halves of the reproductive system. It all comes back to anisogamy. This is the fundamental definition of sex.

Regarding your second point: that there are variations in phenotype, some of them disordered, doesn't mean that "sex is a spectrum". For DSDs, we can describe them in terms of specific developmental differences compared to normal sex development. These are a set of discrete conditions that can be understood without conjuring up ill-defined spectrums. In fact, DSDs in humans have given those who study developmental biology considerable insight into the mechanisms of human sex development more generally.

I see after reading those papers you linked that they further illustrate the point I made earlier: that suppression of testosterone weakens males in some ways, but they still retain physiological advantage from testosterone-driven development earlier in their lives. To advocate for the inclusion of such males in female competitions is to advocate for female athletes to compete at a disadvantage.

If you look at the world records for pretty much every sport, the difference between female and male athletes is very clear. That there exists some overlap between weaker-performing male athletes and higher-performing female athletes doesn't mean that male advantage is significant in almost all sports, especially in ones more reliant on raw strength, such as weightlifting.

You mention the transmen who compete in the Olympics. This is true but they are competing against other female athletes, e.g. Hergie Bacyadan in the most recent Olympics, competing in women's boxing (and in that same Olympics, two males - controversially - won gold, in two other women's boxing divisions). None of them would even come close to qualifying against elite male athletes.

Here is the definition of sex from the Merriam-Webster dictionary:

1a: either of the two major forms of individuals that occur in many species and that are distinguished respectively as female or male especially on the basis of their reproductive organs and structures 1b: the sum of the structural, functional, and sometimes behavioral characteristics of organisms that distinguish males and females 1c: the state of being male or female 3: genitalia

Among those who study gender and sexuality, a clear delineation between sex and gender is typically prescribed, with sex as the preferred term for biological forms, and gender limited to its meanings involving behavioral, cultural, and psychological traits. In this dichotomy, the terms male and female relate only to biological forms (sex), while the terms masculine/masculinity, feminine/femininity, woman/girl, and man/boy relate only to psychological and sociocultural traits (gender). This delineation also tends to be observed in technical and medical contexts, with the term sex referring to biological forms in such phrases as sex hormones, sex organs, and biological sex.

https://www.merriam-webster.com/dictionary/sex

So what dictionary are you using where "sex" is purely defined by gametes? Please use references and support. I have literally provided studies, textbook chapters, and dictionary entries. You're not actually arguing anything, or if you think you are, you're begging the question. Sex is based on more than gametes and we've known that for decades.

> I see after reading those papers you linked that they further illustrate the point I made earlier: that suppression of testosterone weakens males in some ways, but they still retain physiological advantage from testosterone-driven development earlier in their lives. To advocate for the inclusion of such males in female competitions is to advocate for female athletes to compete at a disadvantage.

They literally concluded there wasn't a measurable difference in most of the aspects that they're considering after two years (though there was still an advantage in running after 1 year), so that's a very creative interpretation. There are more studies too, but I can see there's limited point in listing them, since you're reading with your own bias.

Also, keep in mind with the papers that I provided, the authors of these papers are PhDs in this specialty studying trans individuals. Meaning that people who are way more knowledgeable about all this view trans individuals as exiting, since before you seemed to be denying that. Also please notice, that they aren't measuring gametes, they're measuring the effects of hormone therapy specifically and how that might apply to sports. Rules etc in sports, sure, we can measure and change them, but there are plenty of phds out there studying both gender and sex. If you're trying to argue that nuances in the Olympics and college-level sports means trans can't exist, that seems like very faulty logic.

> If you look at the world records for pretty much every sport, the difference between female and male athletes is very clear. That there exists some overlap between weaker-performing male athletes and higher-performing female athletes doesn't mean that male advantage is significant in almost all sports, especially in ones more reliant on raw strength, such as weightlifting.

There are many, many sports where this is not the case and separating between men and women happened late, if at all. Sharp shooting et cetera. There are other sports where yes, there are measurable differences. Testosterone can help in certain sports, that's certainly true, but though that CORRELATES with gametes, it's not absolute, once again demonstrating that what we're actually interested in in sports is testosterone etc, not actual gametes.

> You mention the transmen who compete in the Olympics. This is true but they are competing against other female athletes, e.g. Hergie Bacyadan in the most recent Olympics, competing in women's boxing (and in that same Olympics, two males - controversially - won gold, in two other women's boxing divisions). None of them would even come close to qualifying against elite male athletes.

Incorrect. The transmen are competing against other men. Chris Mosier had an injury at the Olympics, which is unfortunate, but he qualified. In 2015 Schuyler Bailar competed in NCAA Div 1 men's team and did pretty well, top 15%. 2018 Patricio Manuel boxed professionally and won. Transathletes are a small percentage of the population and haven't been allowed at the Olympics for very long, so we'll see what happens there.

Overall, I'm not sure what elite sports has to do with the existence of trans people or human sexual development phenotype or how sex is "only gametes" (or chromosomes, you seem to go between both). The rules in elite sports are always changing, and I'm sure they'll change more. You've essentially assumed your gamete argument is true, despite going against the dictionary, the book chapter I listed, and the studies that I provided, all of which acknowledge trans individuals. This is called "begging the question." If we're going into rhetoric, this is sounding very motte-and-bailey fallacy.

One thing I will say, is that fundamentally science is about asking questions and measuring phenomena, generally using models etc to try to discern causality (probability and statistics). Science is NOT about telling people who or how to be or denying people's experience. Science can tell us what will happen when we take a drug, not if we "should or shouldn't" take the drug (that's for us to decide). In studying other cultures or experiences, science isn't about labeling "good" or "bad," or erasing experiences we don't understand. For example, we know from studying many other cultures and languages that there are multiple understandings of "sex" across cultures, especially where there are explicit terms for intersex et, which is why terms like "gender" can be useful.

I'm not sure why you have such a strong reaction to "trans people exist" or why you're trying to act like your views on it are "scientific," when I have provided (1) textbook, (2) dictionary, (3) studies showing that your views that (A) trans people do not exist and (B) sex and sexual phenotype are only determined by gametes are not supported by science and you have fundamentally misunderstood several key aspects of biology and math (binary vs bimodal). I've provided explanations for how we use models in science and how we talk about data. If you're actually interested in learning about this stuff, I hope some of the resources I have listed are helpful. Otherwise, I'm going to assume that this is not a productive discussion of two people trying to understand the world better. I'm sad this is your view of what science is, and if you're ever actually curious about this kind of thing, I hope you find it interesting.

It is very straightforward to show that sex is defined by gametes.

Imagine a biologist discovers a new sexually reproducing species. She does not yet know whether it is hermaphroditic or gonochoric, nor, if gonochoric, which individuals are female and which are male.

What does she investigate to find out?

She examines gamete production: which gonads produce small, motile gametes and which produce large, nutritive ones. That is the criterion that has defined "female" and "male" across all sexually reproducing organisms for well over a century of modern biology.

Everything else - chromosomes, hormones, genitalia, secondary characteristics - are species-specific downstream mechanisms that evolved to achieve that single binary outcome. They are not the definition itself.

I did ask a version of this earlier in my first reply to you, but I think its significance may have been missed. Anyone with a solid grounding in biology should recognise immediately that gametes are the root criterion. No other answer makes sense.

> It is very straightforward to show that sex is defined by gametes.

I read and corrected your previous comments then, and I will correct them again now. I know this is more or less what they teach in middle and high school biology, just like you might have learned "electrical current is like water flowing between between two voltages" (not a good metaphor, but one that is often taught) and "evolution is the survival of the fittest" (incorrect, but still sometimes taught). What you learn in college is that a lot of the metaphors that were helpful at the beginning can actually make it harder to learn a more nuanced view that's closer to reality. But there's a reason the dictionary definition is different and not just based on gametes. You're confusing applying abstract concepts to individuals.

>She examines gamete production: which gonads produce small, motile gametes and which produce large, nutritive ones. That is the criterion that has defined "female" and "male" across all sexually reproducing organisms for well over a century of modern biology.

Correct, when talking about species as a whole, this is quite useful. "Female" and "Male" can refer to many different types of species. We even refer to asexually reproducing species as "females" by default. Just like "English-speaking" can be a useful general label in numerous contexts. It's great being able to talk about "English-speaking people" as a generalization, but that label doesn't differentiate between someone who speaks at a first-grade level and a college-level. When we're talking about an individual person, we normally take a more nuanced view, as is reflected in the data.

Please see my previous comments on models, binary, etc. Being able to apply a label to something does not necessarily make it true, but we're back at the beginning and I see no point in going over my points again. You're also essentially confusing genotype and phenotype. There's a reason biologists differentiate between that. But again, I've gone over all this already. As someone with a solid background in biology, yes, gametes are important and are great abstractions for talking about specific things, but more than just gametes go into human sexual phenotype and we've known that for decades.

Anyone who has any kind of background in science or engineering at a college level should be able to understand models and data terms, like binary, type 1 and type 2, error, and abstraction. This is fundamental. If you're actually interested in learning more, please reread my previous comments.

* Edit: I missed one of your points.

> Regarding your second point: that there are variations in phenotype, some of them disordered, doesn't mean that "sex is a spectrum". For DSDs, we can describe them in terms of specific developmental differences compared to normal sex development. These are a set of discrete conditions that can be understood without conjuring up ill-defined spectrums. In fact, DSDs in humans have given those who study developmental biology considerable insight into the mechanisms of human sex development more generally.

I already addressed this in a previous comment, but please see Type 1 and Type 2 errors in models. I think the example I used in it was there are no horse-human hybrids (outside of fiction) because we can create a true binary model with horses and humans. That is NOT the case for male and female phenotypes in humans. There are individual humans with both organs, different gametes, different chromosomes, both characteristics etc etc. Obviously-intersex are on the order of red hair in humans, so "it's uncommon" isn't a good counterargument. Again: type 1 and type 2 errors in models.

For your other points about disorders, let's use red hair again. Red hair isn't "a disorder," even though technically it's a result of a type of melanin dysfunction: "Red hair occurs due to a genetic mutation in the MC1R gene, which affects the production of melanin pigments in hair. This mutation leads to higher levels of pheomelanin, resulting in the characteristic red or ginger hair color." It's a normal, but uncommon phenotype. We understand why it happens and how it occurs, similar to intersex. We don't actually know all the types of intersex or how they interplay with each other, but either way, it doesn't honestly matter. If someone appeared with genuine blue-pigment hair, that would break our model. Red hair is just another phenotype in the spectrum of hair colors. Same with grey hair. Same with intersex.

We can list all sorts of things as "disorders" or whatever, which is why we use models to discuss data in science, it's a more structured way of evaluating the world. Types of errors are important in evaluating models. There is as-of-yet no binary model for human sexual phenotype. We still generally sort everyone into two discrete categories, but that's what we choose to do as a society, the data itself is not binary. Just to emphasize this once again: models and data how we evaluate and categorize the world using science. Everyone can apply whatever label they want to something. That isn't science. We make progress in science by evaluating models.

Sex is still very bimodal, no one is arguing that, but fundamentally it's a spectrum. It is not just gametes. We have some of types of intersex listed, sure, but it's also just a normal, uncommon human phenotype.

Intersex has provided insights and is interesting to study. We're in agreement there.

For sports, we're not talking chromosomes or gametes at all. They're irrelevant. What they're actually measuring and evaluating is testosterone, muscle mass, etc, which does CORRELATE with gametes, yes. If we're actually concerned about sports, we'll measure and see what happens. But once again, I can assure you that it has nothing to do with gametes or chromosomes or whatever, and a lot more to do with hormones, muscle mass etc. The studies I listed seemed promising, but I'm sure we'll learn more over time.

I think we're in agreement that ultimately, we want athletes to be able to participate in a way that seems fair, by whatever measure that may be. I'm sure they'll collect more data and we'll decide what we want to do as a society. I am certainly not an expert. The studies I mentioned and several others seem promising. There have been some transmen in the Olympics against other men, though not many. There have also been women who have won gold against men in other sports (skeet I think?) before they were separated. There are obviously several sports where men have measurable advantages to women. For trans-athletes, I suppose we'll see what happens and what the data says.

Absolutely none of this justifies statements such as "transwomen are men." They are not. Sex and gender are both real, useful terms, and they have their own applications. Also, much like genotype and phenotype, they do not always match. Sexual phenotype does not always match genotype (chromosomes), organs etc.

We can see and measure the two groups. We can talk about fairness in sports. It is perfectly fine to talk about measuring differences between transwomen and ciswomen. It's perfectly fine to talk about measuring differences between transwomen and (cis or trans) men. It's even perfectly fine to talk about concern for fairness in sports with the inclusion of transwomen and transmen. All of that is fine.

It is not okay (disrespectful) and incorrect to (1) say that they don't exist (2) say that they're something other than what they identify as. None of that is supported by science. Sex and gender as useful, distinct terms are supported by science. We use those terms to study multiple species, cultures, in whatever forms. Intersex is an uncommon, but well supported phenotype that we literally have records of since ancient times and has been fairly common across many cultures. And across many species. It's honestly so broad it is difficult to define. Literally we have entire hermaphroditic species AND hermaphroditic individuals in non-hermaphroditic species. Similar to homosexuality, it's just a natural phenomenon that happens. You can view trans as part of intersex, or as more of a sociological construct, like gender identity. The data is there.

If you're actually just concerned for fairness in sports, then you could have talked about the athletes in a respectful way ("I'm concerned about the fairness of transwomen in sports with ciswomen"). You chose not to. In general, your way of thinking sounds more like religion than science, and I've heard it all before already.

Science isn't a rhetorical weapon. It's a way of studying, evaluating, and communicating about the world, not imposing judgement on it. There is plenty of data supporting trans, gender, intersex, whatever. There are also plenty of respectful ways to discuss this topic, as previously mentioned.

Why go out of your way to talk about it in a disrespectful way? Why hide behind trying to sound scientific, when it's clear you don't have a background in it? Why the focus on sports?

I think it's time we stop dancing around the topic and get to the meat of this discussion.

I do not consider it disrespectful to state someone's sex, particularly when it's relevant to the topic.

Consider my original comment on this thread:

"Most of the actual work to stop males from competing in women's sports, through evidence-guided changes in policy, has been driven by female athletes who are directly affected by this, feminists and feminist allies, scientists that study sex differences, and experts in the philosophy of sport.

That it's become such a well-known topic of contention is because sports are a spectator event and there have been some very high-profile instances of this unfairness towards female athletes."

Followed by this reply to a user who had a different view:

"They are male, and retain male physiological advantage even if they undergo interventions like testosterone suppression. It's not the only route by which a male athlete with such advantage might compete in women's sport, nor is it an issue limited to the USA. This is a broader issue affecting the fairness of women's sport in competitions across the world.

For instance, all three medallists in the women's 800m at the 2016 Rio Olympics were male. They had been issued with female birth certificates by their home countries due to having underdeveloped external male genitalia - and therefore according to the rules at the time could enter as female - but they still benefited from testosterone-driven development."

There is no disrespect in these comments.

As to why our conversation has focused on sports and sex differences, it is because it was the original topic before you joined the discussion.

As a side note, it's pretty widely accepted that referring to humans as "male" or "female" instead of "men" and "women" in general is dehumanizing. Using it as an adjective "male athletes" isn't considered disrespectful. Your personal opinion that it is NOT disrespectful isn't super relevant, since there are obviously more respectful and relevant terms (transman, transwoman, cis, pre- and post-transition). You weren't actually referring to all "males" in general in the previous discussion, you were specifically talking about transwomen athletes post-transition competing against ciswomen. If this wasn't intentional, then that was part of the confusion.

Some of your comments seemed to be removed, but for clarification, transwomen are women and transmen are men. Why not just use those terms in general? Why say "males," when you are actually talking about transwomen, which is a more accurate and relevant description? Then talk about pre and post transition, since that is the whole point of the discussion surrounding sports (criteria and debates around transition).