I attended the first half of a five hour lecture on:
Sex, Gender, & Orientation: Nature Isn’t Binary
A person’s biological sex would appear too easy to determine. It is not. We are taught that people with XX chromosomes are female and those with XY are male. From a biological perspective, sex and gender are only loosely coupled. Chromosomes, hormones, and the prenatal environment play independent, and sometimes contradictory, roles in determining gender. Epigenetics shows that parental stress factors can permanently affect fetal development. Explore the complex factors that ultimately define a person’s place on the gender spectrum.
The second half is on Thursday. It has been excellent. The speaker has put all the key pieces: hormones, chromosomes, genetics, epigentics, brains, and evolution, out on the table and is building an exceptionally clear picture of what is going on and how all of those factors influence the way folks see themselves and how their particular bodies are built. And it is quite a lot. I do not think there is an online version.

Lots of you would enjoy it and benefit from it.