I read an interesting article in the New York Times today, by one of the principle proponents of memetics, Susan Blackmore. For those of you who don't know, memetics has its roots in Richard Dawkins' The Selfish Gene, where he somewhat speculatively supposes that ideas might change and grow based on the same or similar principles as biological evolution. Since his initial memetion (haha, yeah, I'm not funny, I know) of this idea, it has taken on many forms. Most of them are utterly useless drivel and tripe.
Let's parce memetics down to its simplest possible stated form: "Ideas can change via transmission." I think of this as the telephone game. You whisper to your neighbor that you've just finished work on a neat new idea, and by the time word gets around to Lancashire, you're engaging in orgies with young goats. Memetic ideas aren't quite that trite, but the principle is the same. You take an idea, expose it to a new network of ideas via some method of transmission (like talking to someone), and this new person modifies the idea to suit his or her needs.
This is a load of cock and bull, so to speak. For starters, this isn't evolution, no more than saying that a new airplane design based on groundbreaking materials breakthroughs is the "evolution" of the airplane. Yes, things do change, but ideas rarely change in an evolutionary manner. When ideas are modified, we tend to modify them consciously. This is called design. That most recent rickroll video, say it replaces Rich Astley with the Muppets is an intentional change, not a random mutation.
We can see how natural selection still plays a role though: a good idea might stay popular for a while, though less popular things disappear pretty fast. Still, that's not sufficient to qualify for evolution.
Okay, so memetics doesn't look like evolution, but NDAtheist, you say, you can see the similarities between evolution and memetic change - look at how networks of ideas cross and interact in order to give rise to hybrids or new combinations! That rickroll was a perfect example of the crossing of the "Muppet" meme and the "Rickroll" meme.
I'll happily concede that point, though you'll have to grant me this: evolutionary mutations occur in specific swathes which affect (in general) alleles. So... what's the basic unit of an idea? At what point does an idea change from designed to evolved? This is the root of my objection to the memetic model. Much like how a few beans becomes a mound of beans at some uncertain point (5, 10, 23, 100 beans), when does natural evolution replace design? Moreover, don't other models describe cultural change more completely (some branches of semiotics, what about economic forces and historical forces)?
So... what is memetics good for? It describes ideas that spread rapidly very well. Memes, for instance, in all their internet glory, are well described. Many short lived popular ideas seem to fall nicely within the framework of memetics as well. Which leads to an observation:
Most things that operate memetically seem to have, at base, some anchor idea that is broader and more resistant to change. To use literary terms, memes are like the unique presentation of a broad theme in a particular book, while a broad theme is much slower to change. Popular music often goes on about romance and love, these being central interests to the songwriter, and very much resonant with us as consumers. I want to be loved. You probably want to be loved (maybe we should talk?), and most people have loved or love in some capacity or another. The romantic ideal of love is relatively static. It does change - the 18th century isn't much like today (or even the 60s) as far as specific presentations and understandings of love go. But the basic idea, driven in large part by biological and psychological needs, remains identifiably similar to the same ideas of virtually any other era within the current historical era (say the past 300 to 500 years).
On the other hand, music and poetry are in constant flux as writers and singers find different ways to express the same basic idea. The smaller and shorter lived idea we take, the increasingly applicable memetics is.
Edit: Clarification - There is considerable room for debate here, since ideas certainly seem to be subject to selection (of a sort, possibly similar to natural selection). But mutations in ideas don't necessarily arise from the pre-existing structure of the idea. The inclusion of muppets to rickroll isn't evolutionary. There is nothing in the rickroll that could be manipulated to give rise to muppets. Instead muppets are added in a manner identical (or closely similar) to the process of engineering. Hence the problem with describing memetics as evolutionary in a strict sense.