+1 for Reticulum. Biggest barrier is ease of use, but that’s improving with things like Columba and the most recent reference release including an autodiscovery bootstrap interface.

Not a biologist, but the problem is that sex is a human concept for a natural phenomenon which doesn’t sit neatly into binary conditions.

A zygote is not sexed beyond chromosomal sex because it’s immature. A zygote cannot be said to have genetic, hormonal, or physical sex of any sort because they haven’t developed enough for any such determination.

The confusion arises because the Y chromosome carries largely suppressive genes which prevent the zygote from fully developing feminine characteristics, so laypeople say “we all start out female”. That’s not accurate, it’s a gross simplification, but it’s catchy, so it gets attention.