[VanShuyten]

A good start is for you to study phylogeny/taxonomy. After seeing how different organisms do things, it becomes easier to see how a shark clasper-type organ on a prehistoric fish could evolve into a mamalian penis.

Then take a quick look at embryology. You'll see how human, lizard, and bird embryos all have gill slits. Why would humans have gill slits?

[papertyger]

Embryonic recapitulation has long been discredited There are no gill slits on human embryos.

[DennisR]

... but you have not even come close to answering my seven questions, have you? Why?