A question about chromosomes

What's a woman Planet?

This is a really cogent explanation

Was this a response to my post?

In which case no, it's not testosterone that determines sex, but high testosterone levels are evidence that they don't have a female XY condition, but have instead developed as male, because someone with Swyer syndrome wouldn't produce that much testosterone.

XY = man is an oversimplification, which explains over 99% of the population.

It's the SRY that matters in most cases, which is usually found on the Y chromosome but can sometimes transpose onto the X chromosome.

No man can ever get pregnant and give birth. It is impossible. Just as it is impossible for a woman to father a child. That is the basics of human sexual reproduction and what it means to be male or female.

Can humans make a mistake? Sure. Do humans fully understand the complexities of genetics? No. As our understanding increases, the number of people being incorrectly sexed gets lower and lower.

The boxers clearly don’t have swyer syndrom.

No

XX/XY is a shorthand for female/male because it's true almost all of the time, but it's not 100%.

The SRY gene is what triggers male development, and this is almost always located on the Y chromosome. Sometimes it's not, it's and located elsewhere, so you can find XX men because they still have an active SRY triggering male development.

There are also cases where there is an SRY gene on the Y chromosome but it doesn't activate properly and male development doesn't begin, male puberty doesn't happen etc. and there isn't the male level of testosterone produced.

Whether someone with XY chromosomes but without an active SRY gene is male or female is, I suppose academic, and I'm open as to how a person might be classified.

But relating this to the Algerian boxer Khelif, or Caster Semenya, both have clearly undergone male puberty and are absolutely swimming in testosterone so can't have Swyer syndrome (XY female)

Girls with Swyer's syndrome don't have ovaries, so don't go through puberty unless they get given female hormones (and can't produce eggs). It's a failure to develop male characteristics due to other gene mutations. I assume they would be no stronger than females because they don't go through male puberty or produce testosterone. There would be no problem treating these potential males as women.

The existence of a tiny handful of people with a rare chromosome disorder does not change the fact that women and girls need single sex spaces in certain situations.

Men as a class don’t do any of those things.

Men as a class have two legs.
Just as man with one leg doesn’t contradict that, a man with an anomalous internal reproduction structure doesn’t contradict the fact that men as a class don’t have a uterus.

Men with swyer carry a pregnancy only with massive medical intervention. I’m surprised it’s ethical, given the increased risk to the child. It’s a variation on the idea of men receiving a uterus transplant and being able to carry a pregnancy.

It’s achieved with massive medical intervention.
It doesn’t alter the facts.

Geneticist here. These extremely rare conditions have nothing to do with transgenderism. They are medical conditions and have no connection whatsoever with the belief that people have an innate gender identity that may or may not match with with biological reality. Stop co- opting people with distressing medical conditions in a weak attempt to win an argument.

And in case you're wondering, female is defined as "belonging to the sex class that produces large immotile gametes". That of course does not mean that every member of the sex class does so.

Lots.of people on both sides confuse sex determination with sex identification.

In humans, XY usually but not quite universally gives rise to a male phenotype (sex determination).

We can identify a male in lots of ways. It was done very reliably from anatomy long before chromosomes were discovered. For athletics categories, karyotype from a cheek swab is a good start but if it conflicts with other evidence then more investigation might be needed.

I would think they are the exception that proves the rule. An extremely rare health condition that puts them in a category of their own.

More to the point I wouldn’t have any opinion on their personal medical history, unless they were attempting to claim something they were not entitled to.