From Wikipedia, “Memetics is a theory of the evolution of culture based on Darwinian principles with the meme as the unit of culture. [...] All evolutionary processes depend on information being copied, varied, and selected, a process also known as variation with selective retention.”.
I may be getting this completely wrong, but sounds like what's being posited here is that the culture around memes evolves according to Darwinian principles... And it kind of makes sense!