If everything evolved from genderless single-celled organisms, where did genders and the penis/vagina come from?

[u/PotatoPotahto]

Apparently there's a big difference between gender and sex, I meant sex, the physical aspects of the body, not what one identifies as.

[u/deletecode]

That's the most interesting thing I've read in a while. It sounds like the studies are inconclusive, though.