A simple replication theory of coevolution of genes and memes is
proposed. A population composed of couples of genes and memes, the so-called m-genes, is subjected to Darwinian evolution. Three diíferent types of operations over m-genes are introduced: Replication (an m-gene is replicated with mutations onto an offspring m-gene), interaction (a memetic transfer from a donor to an acceptor), and extinction (an m-gene is eliminated). Computer simulations of the present model allow us to identify diíferent mechanisms of gene and meme coevolutions.