Susan Blackmore, the noted parapsychologist and author of The Meme Machine, gave an interesting talk on memetics at this year's TED conference. (The video is embedded below, click here to go directly to the video at the TED website). While I found her talk interesting and stimulating, overall, I must say I wasn't all that impressed. I have always been skeptical of memetics and "universal Darwinism" because it seems to me at best a potentially interesting rediscription of cultural phenomena, but not a genuine causal account of them. Blackmore does nothing to assuage my concerns in this regard, indeed, she reinforces them. Natural selection, as we all know and Blackmore explains, requires just three assumptions to work: variability, heredity and scarcity. In biological evolution, we know exactly how these mechanisms work even if the details of specific cases elude us. In memetic evolution, however, there is no proper general account of heredity (which ideas are imitated by whom and why) and the accounts of scarcity and variability are somewhat iffy as well. Moreover, I'm not sure the memetic research program has produced particularly interesting or fruitful results, in stark contrast to biological evolution. (I must admit, though, that I don't know the field at all well, I haven't even read Dennett's Breaking the Spell. I'd therefore be happy to stand corrected). In my view memetics is best employed to understand phenomena like the variations on poems like "One Fine Day in the Middle of the Night" or how languages change over time, not as a universal explanation for design.
Blackmore also asserts several blatant falsehoods and commits at least one serious logical error. She claims, for example, that humans are the only true imitators, that other organisms imitate hardly at all. That is utter hogwash: some of the most important ethological findings over the last couple of decades is just how smart some non-human animals are and how many species engage in "differential social learning". Indeed, chimps as well as whales and dolphins have culture and crows are veritable geniuses (pdf). Blackmore even offhandedly suggests humans are the only species that uses tools!
The serious logical error comes in when she argues, amazingly, that humans have big brains in order to copy memes. That is, she argues there is a "memetic drive" favoring brains that are better at copying memes completely independently of genetic evolution. Language, on this view, is a parasite which we only later "adapted to". How such a process is meant to operate I have no idea. Why would selfish genes altruistically code for proteins that build bigger brains to help selfish memes replicate? I can see how memetic evolution could take off as a by product of increased intelligence brought about by biological evolution; I simply can't see how memetic evolution could cause larger brains to evolve in the absence of a biological fitness benefit. If that's right, then it's simply illogical to argue the large human brain evolved in order to copy memes more effectively, and memetics therefore is not nearly as important as Blackmore suggests.
(See also: Blackmore's reflections on the TED conference on her blog).