2. None of this is even remotely new, Im not sure where you're getting that impression from. Germany had an entire institute dedicated to studying trans people at the turn of the 20th century [1]. I'd agree that for a variety of (usually discriminatory and religious) reasons it hasn't been well studied, but trans people certainly arent new.
[0] https://journals.sagepub.com/doi/full/10.1177/24702897188036...
[1]https://en.wikipedia.org/wiki/Institut_f%C3%BCr_Sexualwissen...
2. Transgender is not new. But the broader public debate about the distinction between sex and gender is recent.
Your specific exposure to the public "debate" is recent, sure. But just because you hadn't heard of it before the heritage foundation spent millions of dollars to insure you did didn't mean it wasn't happening.
Surely, if we're trying to group people by biological sex, we'd use chromosomes and ternary logic: male / female / intersex.
You won't easily find support for that on hacker news =)
Like yeah, Im aware HN (as a population) hates women, and GSM in general, but somehow im always surprised by how much yall do.
You shouldn't believe me you should believe science. I'm not arguing any of that go read about it yourself.