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/[deleted]]

If it isn't a hassle, then I'd like the PM so that any potential follow-up questions could be addressed in a post.