This is the last comment I will make to you.
Those who carefully read my previous replies will notice that I absolutely did not step over this question. The book I recommended details more than just animal and ecological examples, it also addresses physiological differences people of different sexes, sexual orientations, and gender identities.
Here’s the truth: the binary categories of male and female are not simple biological ones. Organisms cannot be neatly categorized as male or female, including humans. To put humans into these boxes is to ignore huge grey areas in our understanding of the biology underlying these traits. Even among XX or XY individuals, sex characteristics are polygenic and vary continuously, meaning that even looking at a person’s karyotype (which, you should understand, we hardly ever do) you could not reliably predict the appearance of external genitalia, the presence or absence of other sex characteristics like body hair or breasts, or the identity or orientation of a person.
Although I do not personally believe that having an underlying biological justification is necessary for a trans woman to be a valid woman, there definitely are physiological and biological realities that validate her experiences. Moreover, I don’t think we determine womanhood by biology at all-- for example, a XY human with complete androgen insensitivity would likely not even know HERSELF that she had a Y-chromosome, perhaps for her whole life, and you-- a random person on the street-- would be absolutely unable to tell.
If the question is, then, is there natural precedent for an organism’s sex chromosomes to be unpredictive of their sex characteristics or social roles? The answer is YES, unequivocally. If the question is, is there natural precedent for organisms to be able to intentionally change their sex? The answer is YES, absolutely. If the question is, is there natural precedent for organisms to have a social role that does not match the standard for individuals of their sex? The answer is also YES, 100%, certainly.
Thus, if the question is, are trans people representative of the norms of nature and the biological sciences? The answer is: You fucken BET.
Anyone who claims that trans women are somehow categorically distinct from other women is ignoring how loose the boundaries of womanhood already are. They are trying to twist the facts present under close examination of the biological world to fit their own human social narrative of gender essentialism. The facts of biology are absolutely on the side of trans individuals, this is the consensus among researchers-- and it is being ignored for political purposes in the same way the consensus among researchers on climate change is being ignored.
Like I said, I don’t have all day to engage on this, especially since almost everyone talking about trans people in relation to biological essentialism is not engaging in the discussion in good faith. The take home message is this: if you are earnestly wanting to understand what biological science says about trans people, go read that book, and listen to myself and other experts that trans women have every right and every fact on their side to support their identities.
I just want to be clear (not to this person but to anyone reading) that they are wrong.
They are assuming what they will read as evidence in books and literature. It’s frankly kind of astonishing that I can say “I’m an expert, I’m a biologist, and trans women are women with tons of biological evidence for that validity” and then have this person say “AH but the SCIENCE says I’m right, you just have FEELINGS!”
To be clear, the science says I’m right, the feelings are irrelevant. Toodles!