Do You Have Eggs or Sperm In There?
Trump's Absurd Definition of Biological Sex
Have I ever told you about my $40,000 notebook?
My very favorite class in graduate school was a reproductive biology class taught by a retired medical school professor with a great sense of humor and a lot of anecdotes (not all of which proved to be true). The class met on Saturdays from 8 am to 4 pm. It was long before people carried laptops around, and I took copious notes. I have never been known for having good handwriting. It slopes to the right, and by the end of the day, it was hard to read at best.
I would spend some time during the week recopying my notes on dark-lined, narrow ruled paper with a skinny tip pen (I’m a 0.5 girl in a 0.7 world), clarifying things as I went. The act of doing so helped me understand the material and cement the information in my brain so that I could see pictures of the pages when it was time to take the test. (I got an A+ in the course. Toot-toot.) The resulting notebook is a great reference, at least for me, and it only cost me 40k in tuition. Hence the name.
I took the notebook off the shelf this this week after Trump’s anti-trans executive order came out with this absurd definition of biological sex:
“Female” means a person belonging, at conception, to the sex that produces the large reproductive cell.
“Male” means a person belonging, at conception, to the sex that produces the small reproductive cell.
As a friend said, it’s straight out of a 15th century medical textbook where it’s probably followed by a way to test whether women are witches. It’s barely been a week, and this was far from the first that’s not how it f**king works moment. It might not even be the worst of them, but I find it particularly frustrating because it’s provably incorrect.
So come with me on a deep(ish) dive into fetal sexual development by way of an order comically called “Defending Women from Gender Ideology Extremism and Restoring Biological Truth to the Federal Government.” I mean, what the f**k?
We’ve all heard biological sex boiled down to whether you have a penis or a vagina (four-year-olds are really good at that dichotomy). That’s usually how sex is assigned at birth, because it’s easy to see. We may have also heard it described at the chromosomal level with XX being a girl/woman and XY being a boy/man. Reducing it to whether we will make eggs or sperm after puberty is a new one (or, as I said, a very, very old one). So right off the bat we know we’re not in medical or scientific territory.
Another way we can tell that we’re not doing this by the textbook is the use of the word conception, which is a religious term. This is a not-so-subtle attempt to get fetal personhood language into our rules and laws. Before SCOTUS took such a sharp right turn, when anti-abortion advocates wanted to codify the idea of a fetus as a full human with rights that may very well trump the rights of the person carrying it, they would at least use the term fertilization because that is a medical term. No need to pretend now. If fetal personhood becomes accepted, abortion becomes murder with penalties such as life in prison or death.
Yes, they used an anti-trans rule to shore up anti-abortion policies (the next four years are going to be so much fun).
Whether you call it conception or fertilization or even start the clock at implantation, suggesting that an embryo has a sex from the very start is wrong. We are all undifferentiated until at least six weeks of development. The idea that everyone develops either male or female is also wrong. There are lots of steps—and lots of ways things can differ from the norm—along the way.
The differentiation actually starts before sperm and egg come together (whatever you’re calling that). The first time I taught a college-level human sexuality class was in a science department, and I had to do a lecture on mitosis and meiosis (I drew transparencies to use on the overhead projector). I’m not sure I remember enough to give that lecture again even with the notebook for reference. For now, it’s sufficient to know that mitosis is the way most cells divide, and meiosis is how sex cells—sperm and ova—divide. Meiosis is supposed to end up with ova that have one X chromosome each and sperm that have either an X or a Y chromosome.
Sometimes that’s not how it happens, however. This means that sometimes you end up with an embryo that has one X chromosome and nothing else (XO), which causes Turner’s syndrome. Sometimes you end up with an embryo that is XXY (Kleinfelder’s Syndrome) or one that has XYY syndrome. You can also have an XX male because one of the X chromosomes has a little but important piece of a Y chromosome on it. Or you could have an XXX metafemale.
In all of these cases except XXX there will be certain anomalies that makes a person’s external genitalia appear different or their internal reproductive organs function differently. They may also have other differences in appearance such as a webbed neck, nipples that are further apart, or unusual height (tall or short). In the case of metafemales, the body just discards the extra X chromosome along the way and most people will never know.
You’ll notice there’s no such thing as YO. That’s because we all need at least one X chromosome to develop (yes, the future is female). In fact, during development if you “do nothing,” all embryos will become female.
Embryos begin by creating undifferentiated gonads. There’s a protein on the Y chromosome called TDF (testis determining factor) that tells those gonads to become testes. If the Y chromosome doesn’t have TDF, the gonads will go on to become ovaries instead.
The testes are then supposed to produce testosterone, and it’s this sex hormone (or lack of it) that controls the development of the rest of the internal reproductive organs. There are two sets of ducts (Wolffian and Mullerian) that either break down or become things like the fallopian tubes, uterus, and upper part of the vagina or the seminal vesicles, vas deferens, and epididymis. With testosterone you’ll get male internal development. Without it you’ll get female.
Hormones (testosterone and later estrogen) are important in the development of external genitals as well. You may have heard me say that the clitoris is analogous to the penis. That’s because in its undifferentiated form it’s the same structure, just how the structures that make up the scrotum could instead develop into labia. See the picture below and then examine some genitals in real life (yours or someone else’s). It’s kind of fascinating.
There can also be variation in either the external or internal differentiation process because of hormone issues. An XY embryo may create testicles, but the testicles don’t produce testosterone. Or an XY embryo may create testicles, and the testicles produce testosterone, but other systems in the embryo’s developing body aren’t able to process testosterone. Or perhaps only some cells are able to process testosterone.
The modern phrase for these issues is Disorders of Sexual Development. People born with DSD are often called intersex, though not everyone identifies with or appreciates this term. In some cases, the differences in sexual development are immediately visible at birth. A baby may be born with an enlarged clitoris or a very small penis. In other cases, the differences don’t become apparent until puberty when a person doesn’t develop as expected. Some people may not know until they struggle with infertility. Others may never know at all.
(One of the anecdotes my professor told that is true is about a small community in the Dominican Republic where a genetic mutation that causes the genitals to look female at birth and change rapidly at puberty is well known. Their testes descend and their penis—which was likely mistaken for a clitoris—grows. These individuals are referred to as "Guevedoces,” which roughly translates to “penis at 12.”)
Intersex individuals are not the target of Trump’s attack, they are merely collateral damage. The real targets aren’t people who are born different, but people who identify differently than expected after they are born. Unlike biological sex, gender identity manifests after we’re born as we learn what it means to be male or female, figure out how we feel about it, and express ourselves accordingly. (There is research to suggest that hormones in utero may impact gender identity as well, but it is far from settled science.)
The Right is obsessed with the idea that someone’s gender identity might not match what’s between their legs. I can’t wrap my brain around their objection exactly, except that it falls at the intersection of sex and “different,” and that makes people feel squidgy.
Politicians have seized on this and turned trans people into the boogeyman that they need to sow fear and division. They did this with gay people and same-sex marriage in the early aughts, but that stopped winning elections, so they needed something new.
Last year, there were a slew of anti-trans bills targeting what bathroom someone can use, what sports team they can join, and whether their parents can make medical decisions for them. This election season we got Trump saying that kids were getting gender reassignment surgery at recess without a parent’s consent. (Anyone who has ever had a child in public school can spot the bulls**t dripping off of this one: the nurse can’t even give a kid Tylenol without written permission from a doctor in triplicate.)
The goal of the order is to erase the identity of trans and nonbinary people (and intersex people as a byproduct). The order itself removes protections for transgender and non-binary people such as selecting an X for gender on their passports or using the bathroom for the gender they identify with. (Apparently, Lauren Boebert has volunteered to be the country-wide bathroom police.) The order also impacts federal prisons, migrant shelters, and rape/domestic violence shelters by requiring them to be segregated by sex as defined by the order.
I realize that the medically absurd definition is not the biggest issue with any of this. The impact of this order will be to make people’s lives less safe. There has already been a rise in anti-trans violence and hate crimes in recent years. GLAAD has recorded over 2,000 incidents of anti-LGBTQ+ violence since the start of 2022. Transgender people are over four times more likely than cisgender people to be victims of violent crime. We also know that transgender young people face more mental health challenges and an increased risk of suicide. A 2024 peer-reviewed study published in Nature Human Behavior found that anti-transgender state laws directly caused an increase in suicide attempts among transgender youth by up to 72%.
All of this is dangerous and horrifying. Focusing on why it’s also flat-out wrong could be seen as missing the forest for the trees, and the forest is bigger than just sexual and reproductive rights issues. Robert Reich had a pretty convincing piece earlier in the week that suggested the blitz attack on social issues was intentional busy work to keep us from noticing all of the ways they’re trying to fundamentally reshape our government into an oligarchy. (Perhaps the scariest part of his explanation was that the plan relies on Trump dying and JD Vance being Peter Thiel’s puppet president.)
I don’t disagree. There are probably more important things to do here than explain the difference between Wolffian ducts and Mullerian ducts, but I do still think facts matter. Or at least I want them to. Also, explaining things carefully helps ground me, whereas thinking about the intent behind rules like this or the bigger picture end of Democracy just makes me sad, rageful, and afraid.
Screaming “that’s not how it f**king works” into the forest will likely not make a huge difference, but I don’t want to live in a post-fact world. Hopefully you’ve now learned something from my $40,000 notebook, but don’t worry. I don’t expect anyone to have taken notes with an extra fine tip pen and I promise I won’t be giving a quiz next Wednesday.