Comment by zz3

Comment by zz3 12 hours ago

5 replies

Sure! It's pretty trivial. I'm going to assume at least a high-school knowledge of math, since I'm assuming you're unfamiliar with terms like bimodal distribution, categorical data, et cetera. If you're interested in learning more, this kind of thing generally falls under statistics.

So this boils down to the question of essentially "if everything is on a spectrum, how can we categorize it?" and the answer basically boils down to "it's arbitrary." This is essentially called analog-to-discrete conversion. To skip ahead, human sex is on what's called a bimodal distribution. That means there's two big bumps on either end of the spectrum, and very little in the middle, but it's still accepted to be a spectrum. We can just "summarize" it by sorting them into discrete categories. Let's use voltage as an example! Common voltages have 0V for "False" and 1V for "True," right? For discrete signals. But what if the voltage is .3V? If the exact voltage isn't important, we can "summarize" it by setting an arbitrary limit (generally .5V), and then anything below gets summarized to 0V or "False," and anything over or including .5 V gets sorted into 1V or "True," but it's important to note that this has NOTHING to do with the underlying voltage we are measuring. The limit is arbitrary and we're only doing it because the exact measurement in this particular case isn't that important. Science is like this in general: we have the data that we don't understand, and we try to categorize it to make sense of it. But this obviously fundamentally doesn't change whatever we are actually measuring, this is just how we are defining and categorizing that information.

We don't have to imagine other forms of sexually reproducing species; we have many, many, many other examples across life, insects, mammals, bacteria all have different ways of combining genetics and reproducing. Clown fish are pretty much all hermaphrodites and can switch genders under stress, and this isn't that uncommon. There are plenty of examples of intersex individuals who can still reproduce, and plenty who can't for a variety of reasons. Humans are one of the few species that go through menopause, for example. The general idea for this two is talking about general reproductive strategies (for example, XY chromosomes etc etc) is different from talking about an individual, which might be sterile, intersex, whatever. This also is where societal roles come into play et cetera. This is a much larger discussion, though, and it would be difficult for me to summarize here, but I hope I've at least given you some terms so you can understand what's happening. Basically what science does is work from a bottom up approach: we have a lot of data, and we try to understand what is going on by applying labels and seeing if that helps, but these labels and limits are all changing and arbitrary, it doesn't actually affect what we're measuring. We try to use words to describe biology, we can't use words to influence biology, if that makes sense. A statistics class would probably help describe this better.

Edit: So part of the reason why I initially responded was because I was hoping to understand your perspective a little better, since I've heard it before and I find it fairly perplexing. I have a background in biology, science, and engineering in general, and this is just generally how science is done, I haven't said anything particularly controversial here as far as I'm aware. We create models based on what we think is happening, come up with a hypothesis and an intervention and then we experiment on it and try to see how our model compares to what's actually happening. We try to update words to match the data that we see, we don't try to impose words on data, that seems backwards. Are you open to talking a bit more about how you're thinking and reasoning about this?

BolexNOLA 10 hours ago

Just want you to know I appreciate all the hard work you’re putting into trying to educate somebody even if it is likely they will barely register it. I’m sure others like myself found the write up overall interesting and helpful.

  • zz3 10 hours ago

    Thanks! I find all this super interesting, and I hope other people do too! It's a pretty wild world out there.

fringol_ 7 hours ago

[flagged]

  • zz3 6 hours ago

    Sure! I think I understand what's going on here. I think we're having a few different misunderstandings, let me see if I can describe them.

    By "human sex" I'm referring to everything that developmentally contributes to a human sexual genotype or phenotype. Here is a fun textbook example of all the things that go into human sexual development: https://open.lib.umn.edu/evosex/chapter/8-7-variations-in-hu...

    From all these variables alone, we know there is some kind of spectrum to human sexual development. When we say something like "binary" that specifically means a discrete data type: true or false (nothing in between). Binary explicitly means there are two options and nothing else (discrete). For example, humans and butterflies, there's zero half-human half-butterfly hybrid. They're discrete. Most things in real life, however, are some form of continuous spectrum, and that's where "spectrum" comes is. We already know based on how many variables go into human sexuality that it's some form of spectrum for an individual, at the very, very least: male, some kind of intersex, or female. It's not binary (two options) for individuals.

    (NOTE: also this is just for humans. As I mentioned, "female" and "male" aren't even that useful in a large part of life on Earth. There's a type of sea slug that essentially has penis battles to determine who donates which gamete, essentially, since every individual is capable of both at all times. As I mentioned before, all clownfish are hermaphrodites, they can switch if they need to. Many frogs and lizards can be too. That's why "female" and "male" are such abstract concepts, trying to describe generalized reproduction can be pretty gnarly once you get into any kind of detail, so no wonder the terms are fairly overloaded).

    As I mentioned before, some of the factors that go into human sexual development include (1) number of chromosomes, (2) number of X's and Y's, (3) SRY gene on the Y chromosome, if present, (4) human sex hormones including the many forms of estrogen, testosterone, androgens etc, (for this discussion, probably not hormones like FSH, LH etc), (5) the receptors for these hormones. All of these things (and more) go into human sexual development. But you might have already noticed an issue with it: for example, all humans, regardless of sexual phenotype generally have both testosterone and androgens ("male" hormones) and various forms of estrogen ("female" hormones), so how does that work? How can we "measure" "sex"? What even is "sex"?

    There's a few different abstractions at play. There's general abstractions like "female" and "male," which have multiple meanings. When we're making big generalizations about reproduction, it's helpful to talk about two general types of roles for mammals. For example, the male and female gametes for mammals are ova and sperm. We can also use it to talk about male and female hormones, estrogen, androgens, progesterone, FSH, LH, testosterone, to name a few. These are useful for talking about general reproductive abstractions, but each individual has aspects from both of these abstractions (estrogen, testosterone, androgens), so it's not a one-to-one mapping. You can't say "oh, human sexuality is determined by chromosomes," because it's not: XXY, XYY, and SRY gene all exist. You can't say "human sexuality is completely based on gametes" because hermaphrodites can have both ova and sperm, so are they male or female? That kind of thing. There's no "one determining" factor for human biological sex. Multiple things go into it, and therefore it's some kind of spectrum based on all the factors that go in.

    When we talk about gender this becomes even more readily apparent. There's no "one determining factor" for what makes a woman or a man. It can't be chromosomes, SRY, hormones, gametes, or any one thing alone. We also know that it can't purely be about reproduction: infertile or sterile men and women can still be considered men and women. And this is just English, there are plenty of other languages that have had and have always had more than two main gender roles etc. So what on earth is it? The truth is, it's literally just an arbitrary line in the sand that we're trying to come to some form of consensus on. In general, we've found the most respectful way to do this, is to treat everyone as fully functional humans and have them self-report based on their language, culture, experience et cetera. Language and words are constantly changing and updating with our understanding, so whatever we decide on today, might change in the future too and that doesn't matter either.

    Does that help the discussion at all? This is all fairly standard, there are quite a few textbooks on it, including the one I linked if you're interested.

    • fringol__ 3 hours ago

      That textbook chapter you linked is quite revealing, thanks. I see that diagram in particular as a good demonstration of how the "sex is a spectrum" concept can't possibly work in practice. The number of arrows criss-crossing back and forth shows how impossible it would be to order disorders of sex development (DSDs) into a spectrum in any logically consistent manner.

      More importantly, there's not really any reason to do so, as every one of those DSDs can be explained with the binary sex model and a mechanistic understanding of human sex development. Take 5-alpha reductase deficiency for example, it's caused by mutations in the SRD5A2 gene, which adversely affects conversion of testosterone to dihydrotestosterone, causing internal testes and an underdeveloped penis, but otherwise normal male sex development including testosterone-driven male puberty. It would be pointless to try to place this somewhere on a spectrum, as it offers no additional explanatory power and just obfuscates the detail.

      In your spectrum model, you seem to be using the word "sex" to describe some sort of undefined (and apparently undefinable) composite statistical scoring of a set of dissociated sex-linked characteristics, that is focused almost entirely on those present in humans. However, this is not how biologists would typically think of sex. Fundamentally it is about evolutionary questions, like: why does sex exist, why is it a stable reproductive strategy across almost all complex life? And it is about developmental questions: what makes sexed bodies, what are the underlying mechanisms? I don't understand how adopting a "sex is a spectrum" belief would help answer these.

      You mention hermaphrodites but again I don't see how the spectrum model does anything but fail here? It offers no useful insights - the binary sex model is perfectly adequate to explain that an individual embodies both female and male halves of the reproductive system.

      I hope this helps clarify my points, interested to read your response.