1. Nerd of Redhead, OM says

    How do you get two separate sexes with two separate reproduction systems by natural selection, which takes time.

    Shiloh, three things. We don’t have to satisfy you with the science. You have to satisfy us with any other explanation than science.

    Second, there is this search function called Google Scholar. Designed to look for research papers.

    Three, from the first page using “evolution and sex”:

    Book A
    Book B
    Article A
    Book C

    The information is there. You should look for it on your own.