Hmmm...
I have a doctorate in genetics and worked as an academic medical genetics researcher for over a decade. So, I think I can claim to know a bit about biology, although sex/gender wasn't my field.
I 'peak-transed' a couple of days ago thanks to you guys alerting me to the fact that the meaning of the word 'woman' is being usurped, and the potential unintended/intended consequences of that.
Sex is (mostly, barring the occasional rare genetic anomaly) straightforward in humans i.e. XX = female, XY = male
Gender is less so. Like many of you, I feel that gender can be a social construct which is frequently detrimental to women, kicked against being a girl as a child and have no strong sense of my own gender now. But someone posted a link to an article in Nature on that thread in AIBU about the Daily Mail article yesterday, which does provide some evidence of a physiological basis for transgenderism nature.
Importantly though, while there were brain differnces between men, transgender women (born men), and women. The brains of transgender women were very similar to those of men, which were clearly distinguishable from those of women.
So, based on that, I am coming to the idea that transgender people are a comparable to those with high functioning autism in some ways - i.e. clealy different to those without the condition, but not necessarily in a pathological way.
It also reinforced the idea that transwomen =/= women.
I haven't read the report from the BCP yet.