Two... semi-weird looking gametes pair up.
Produce a kind of, sort of, not really good looking diploid zygote.
That zygote... goes out into the world. Let's call zygote, "gene" now.
Gene goes out and finds another gene that is weird looking. Genes have hot gene sex. Produce little genes that are simply fucking ugly.

Here's the thing. I hate the fact that the ugliest people breed the most. (Not in all cases... but in most cases). Most of the people i'm talking about, have children and grandchildren that look like the products of incest. Hmmm... wait a minute...