Susan Blackmore
Susan Blackmore had the guts to pick up the idea of the meme, a cultural analogy to the gene, which seems to display the critical properties of reproduction, competition and variation required for the production of elaborate structures. Yet the meme itself has cheerfully defied definition.
On the present view, memes are collective phenomena defined over P-worlds, and may be no more circumscribable than a wave is in water. But waves can be studied for all that, once their nature is clear. This is one interesting way the P-R distinction may be developed. More in the blog, eventually.