There is a metal thread, and we actually discuss these genres a lot in there.
"My goal this year is to prove natural selection on the show. It's gonna take a while, it's gonna be very hard to make it fascinating on film in the context of our narrative structure, but I figure screw it. The sky's the limit. Let's do natural selection. I'm sick of fifty percent of this country thinking creationism is reasonable. It's appalling."
Adam Savage of Mythbusters