Originally Posted by
billl
In the brief summary at that Wikipedia link, I don't see any objections to the "physical existence of memes", but rather to their definition (or the usefulness of their conceptual role). We see ideas replicate, spread, die away, etc., but they don't have an internal code (like DNA). So a meme is different from a gene in that way, and thus perhaps genetics (and all of the processes involved in genetics) is not a suitable metaphor for them. There is also, at the end, an objection made by a semiotician, who seems to basically think that memes sort of make a mess of a conceptual system he's already been involved in (but he isn't wondering about what the material manifestation of memes would be, because it would be of the same nature as the signs that he speaks of).
When people study or talk about memes, there should be no question about what memes are made of: they are made of brain cells, ink on paper, sound waves, etc., even made of something like (in a "famous" Susan Blackmore example) the triangular fold at the end of a roll of toilet paper in a freshly cleaned hotel bathroom. To wonder where memes materially exist, and to be skeptical on such a basis, is similar to wondering where ideas and traditions materially exist and therefore being skeptical about those.