I watched his sermon. Snakes have both male and female reproductive organs and impregnate themselves. If snakes don't need mates, who's to say the first sexual organism did?
Are you sure?
Can snakes impregnate themselves
Answer
They cannot impregnate themselves per say but they can retain sperm from one breeding to the next as well as have litters from multiple partners.
Just to add to this thread: There was a man who claimed not too long ago that his snake impregnated itself. He claimed it had never been in contact with another snake. I think its his word against science, but just for the record their have been people who have said such things...