  Perhaps the most popular attempt to understand cultural evolution is Richard Dawkins’ (1976) invention of the “meme.” Dawkins observed that what lies at the heart of biological evolution is differential reproduction. Evolution in general was then the competitive dynamics of lineages of self-replicating entities. If culture was to evolve, on this view, there had to be cultural “replicators”, or entities whose differential replication in culture constituted the cultural evolutionary process. Dawkins dubbed these entities “memes”, and they were characterized as informational entities which infect our brains, “leaping from head to head” via what we ordinarily call imitation. Common examples include infectious tunes, and religious ideologies. The main difficulty with this approach has been the problem of how to provide specifications for the basic entities. The identity conditions of genes can be given, in theory, in terms of sequences of base pairs in chromosomes. There appears to be no such fundamental “alphabet” for the items of cultural transmission. Consequently, the project of “memetics” as a contending basis for evolutionary epistemology is on hold pending an adequate understanding of its basic ontology. The online  Journal of Memetics contains some early papers on memetics. Although the journal has ceased publication, the existing papers are still accessible online. See Atran (2001) and Sperber (2001) for reservations about the viability of memetic models of cultural evolution. For a recent defense of this approach, see Dennett (2017).