It's hard to argue about this without some idea about what the original author considers "real"/"not a myth". If he considers genes to be "real" in comparison

It's hard to argue about this without some idea about what the original author considers "real"/"not a myth". If he considers genes to be "real" in comparison (which I cannot totally infer from this piece of writing; but he does seem to put a lot of stock in the identification of a physical mechanism for projecting the idea of genetics onto, in DNA), there's a pretty straightforward map-vs-territory argument to reduce that (and pretty much everything else) to equivalence. All of thought and semantics are imperfect metaphors. The question "are memes real" is exactly equivalent to "are genes real" is exactly equivalent to "is math real" is exactly equivalent to "are trees real" is exactly equivalent to "is anything in our understanding of reality real". Short of a physical "theory of everything", the only description of physical reality that is "real" is the total enumeration of all of physical reality.