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[–]Juniperius 13 insightful - 1 fun13 insightful - 0 fun14 insightful - 1 fun -  (6 children)

I'd say you've got it exactly backwards. Sexual dimorphism is a term we use to talk about how different the males and females of a species are. For example, male gorillas are nearly twice the size of female gorillas, as opposed to humans, where the males are around 10% taller. So gorillas hav more sexual dimorphism than we do. Or think of birds, the different colors between males' feathers and females'. On the other extreme, I would have no idea how to tell the difference between a male housefly and a female housefly; they have much lower sexual dimorphism, although I'm sure scientists who study them could describe to me what differences there may be. Basically, if you take a male example and a female example from a given species, what differences will you see, in things like size, shape, color, amount or distribution of hair or feathers or whatever?

Obviously within one sex attributes will fall along some kind of normal distribution: there are taller men and shorter, more and less hairy, there are taller and shorter women, women with larger and smaller breasts, etc. But a shorter man is not more female than a taller man, because the dimorphic attributes are just a result of sex, not a cause of it. Which sex a creature is just means which role it is capable of playing in reproduction (supposing it's healthy and so forth). The external traits, which may be more or less dimorphic depending on species, might help you figure out what sex an individual is, but they do not determine it.

There's a kind of fish (sorry, I never remember the names of these things) where the males and females mostly look different and live separately, but a few males take on a female-looking form, a disguise, so to speak, and slip in with the female school. This strategy allows them to fertilize the females' eggs without having to compete with other males. In other words, they are still firmly within the male reproductive role (fertilize eggs) even though they appear female in terms of the superficial dimorphic attributes.

Most of the attributes mentioned in your comment, which the people you quote claim are part of the definition of sex, are not. Sex is which part of reproduction an individual can potentially provide. In humans this starts with which chromosome is provided by the sperm that fused with the egg to make you. The genes on that chromosome provide a blueprint according to which a body is built that in turn goes on to produce eggs or sperm. Egg-producing bodies and sperm producing bodies have different average size, shape, biochemistry, etc, which all fall under the category of sexual dimorphism, and while some of them may have some consequences for reproductive fitness (a woman whose hips are too narrow might have difficulty in labor, for example), they are not, themselves, of any importance in figuring out what sex someone is.

[–]SilverSlippers 12 insightful - 1 fun12 insightful - 0 fun13 insightful - 1 fun -  (0 children)

Having different types of gametes is what defines sex. Without it there are no sexes. Species that don't produce gametes don't have sexes. Sexual dimorphism refers to differences in phenotype between sexes (i.e. individuals with of the same species that produce different type of gametes). Sex is indeed just the type of gametes an individual produces (or has the equipment to produce). Traits related to sex outside of the sexual organs themselves are secondary sexual characteristics. When talking about sexual dimorphism, we are only talking about secondary sexual characterizes, not the gametes or sexual organs. Sex itself is binary. Many secondary sexual traits are bimodal (i.e. breast size, height, adam's apple size, etc).

A good example of what no sexual dimorphism looks like in a sexual species is society finches. You cannot determine the sex of an individual by observing them or their behavior. The only way to determine the sex of an individual is to examine them to determine whether they have ovaries or testes (or do a DNA test). Extreme sexual dimorphism would be something like anglerfish. What we think of as anglerfish are all female, the males are tiny parasitic fish that merge with the female and become nothing but a pair testicles. Humans are obviously somewhere in between. We have clear sexual dimorphism, but it isn't extreme.

[–]peakingatthemomentTranssexual (natal male), HSTS 11 insightful - 1 fun11 insightful - 0 fun12 insightful - 1 fun -  (0 children)

I’m not sure if I’m understanding the question entirely. Like, if sex is defined by gametes, which I think it is, there are only two types of gametes and nothing in between them. It seems like that has to be binary rather than bimodal. I don’t think gametes can be a result of dimorphism either because they are very different even apart from size. I’ve only heard dimorphism used to refer to traits. Traits among females and males are a distribution with a lot of overlap though so maybe that is what they are getting at. Those traits aren’t sex though. Plus, many of those traits can be changed and do change throughout someone’s life (to varying degrees). For instance, characteristics of my body include breasts and a vagina (or at least something like one 🤷‍♀️), but it is still a male body because I was born male, just not a typical one. Like, using sex to describe someone can be less useful in those situations, but that isn’t a reason to try to pretend sex is something other than what we’ve known it to be throughout human history. 100 years ago, no one had any trouble knowing who was and wasn’t supposed to vote or who the 19th amendment was for. It’s silly we’re pretending like it’s complicated all of a sudden.

[–]CatbugMods allow rape victim blaming in this sub :) 8 insightful - 1 fun8 insightful - 0 fun9 insightful - 1 fun -  (0 children)

Sex isn’t sperm or egg. Sex is which you would produce.

[–]emptiedriver 8 insightful - 1 fun8 insightful - 0 fun9 insightful - 1 fun -  (0 children)

This is the confusion of sex and gender that is always getting us into trouble. Sex is a technical fact, and it is binary and absolute. Which reproductive role is your body capable of playing (or would it be if its reproductive organs were working properly)? There are only two options, and if neither is more accurate then your body is a very rare case - but it also is technically not sexed. To have a sex, your body was born with the basic reproductive potential of one or the other sex. As a female, you are born with hundreds of eggs inside you.

Gender is the larger category we use to describe sexually secondary features, "typical characteristics", and further identity aspects. It's performative, interactive and social. It can be very important, but it doesn't have to be validated as a sex - some people are perfectly happy to be understood as MiT/ FiT and see their genders as distinct from the biological, and some GC types have no problem respecting gender preference when it is social, so long as it does not overlap the legal or take away rights of women as a political unit.

That's why the biological has to be clarified as separate. Women are females, born with eggs, the capacity to menstruate & be impregnated: that's historically, politically, culturally central to our story and our connection to each other. Males who bond with women on a social level can become great friends and for some people the closest "girlfriends" of all, but politically they are allies rather than members of the class.

[–]Iced_Iced_Vovo 7 insightful - 1 fun7 insightful - 0 fun8 insightful - 1 fun -  (0 children)

Hi - Sexual dimorphism is where the two sexes appear differently (google peacock and peafowl) the showy, pretty plumage of the peacock is a great example of sexual dimorphism (the peafowl - female- is just a brown bird in comparison). in the case of the peacock, the sexual dimorphism is probably to attract the female.