Why does blood clot? Aliens. I have no empirical data or reproducible science, but evolution is complicated so I'll just say aliens make blood clot.
From a letter to the editor's description of evolution and the alternatives. Put it in your scrapbook for use when the school board requires you to discuss differing theories of human origins in a science class. Distribute a photocopy (I'm 100% certain that the author, Adam Broyles, won't complain about copyright violations, even if fair use didn't protect you) and you'll have discharged your legal obligation to discuss the issue.