On one point, though, I insist. This is that wherever in nature there is a sufficiently powerful illusion of good design for some purpose, natural se… - Richard Dawkins

Things exist either because they have recently come into existence or because they have qualities that made them unlikely to be destroyed in the past.

No doubt some of your cousins and great-uncles died in childhood, but not a single one of your ancestors did. Ancestors just don't die young!

Examples of memes are tunes, ideas, catch-phrases, clothes fashions, ways of making pots or of building arches. Just as genes propagate themselves in the gene pool by leaping from body to body via sperms or eggs, so memes propagate themselves in the meme pool by leaping from brain to brain via a process which, in the broad sense, can be called imitation.