Natural selection is a form of evolution that is favorable to the weak and not the strong.
Natural selection is proof positive that providence favors the lusty over the learned, and that human evolution will eventually return us to our rowdy paleolithic roots.
Natural selection explains how bacteria will gain antibiotic resistance or how insects get insecticide resistance, but it doesn't explain how you get bacteria or insects in the first place.
Natural selection is the process that has brought all living things to be the way they are, is best seen at the gene level, is best seen as a process of differential survival among genes, and therefore living organisms and their bodies are best seen as machines programmed by the genes to propagate those very same genes.
Natural selection is the reproductive screening process by which the gods determine whose genes will represent the future of the species, based solely on a proclivity for fruitful sex.

Natural selection is the principle, by which each slight variation, if useful, is preserved.
Natural selection is a weakening process, not an empowering one. Species do not grow more perfect, rather they grow weaker. The weak, being more numerous and more clever, continually dominate the strong (who become so strong that they abandoned mind as unnecessary).
Natural selection is a phenomenon that does not bode well for monks, nerds, women with ticking clocks, reclusive scholars, a significant percentage of interior decorators, and other mild-mannered gentlefolk.