I don't know for sure about scholarly work on memes, but language changes over time. Language is used to convey ideas, and in turn is changed, shaped by which ideas need to be represented in different cultures and different times. Maybe on some level you could consider components of language (words, grammatical rules) to be that discrete unit.
Languages definitely have been classified phylogenetically/cladistically. Drift and change eventually leads to different languages stemming from a common ancestor. See for instance Indo-European languages or even Nostratic languages.
For instance, on a more granular level, examples of this phenomenon would be the more and more common confusion between "it's" and "its" or "your" and "you're" as well as "they're" and "their". It's a minor drift, a permutation which seems almost a neutral mutation at a very low level of language. But I see people using it more often, even educated people who seem to have otherwise perfect command of English (I couldn't find scholarly work on this topic though).
Language is used to convey ideas, and in turn is changed, shaped by which ideas need to be represented in different cultures and different times. Maybe on some level you could consider components of language (words, grammatical rules) to be that discrete unit.
Not unless you want to confine memes to language. Memes are intended as general units of cultural inheritance - and are not specific to language.
My two cents on the subject may be found in the article: Are memes discrete?.
"All models are wrong, but some are useful" — George E. P. Box
As a student of linguistics, I’ve run into the idea of a meme quite a lot. I’ve even looked into some of the proposed mathematical models for how they transmit across generations.
And it certainly is a compelling idea, not least because the potential for modeling cultural evolution alone is incredible. But while I was researching the idea (and admittedly, this was some time ago; I could well be out of date) I never once saw a test of the model. Oh, there were several proposed applications, and a few people were playing around with models borrowed from population genetics, but I saw no proof of concept.
This became more of a problem when I tried to make the idea pay rent. I don’t think anyone disputes that ideas, behaviors, etc. are transmitted across and within generations, or that these ideas, behaviors, etc. change over time. As I understand it, though, memetics argues that these ideas and behaviors change over time in a pattern analogous to the way that genes change.
The most obvious problem with this is that genes can be broken down into discrete units. What’s the fundamental unit of an idea? Of course, in a sense, we could think of the idea as discrete, if we look at the neural pattern it’s being stored as. This exact pattern is not necessarily transmitted through whatever channel(s) you’re using to communicate it — the pattern that forms in someone else’s brain could be different. But having a mechanism of reproduction isn’t so important as showing a pattern to the results of that reproduction: after all, Darwin had no mechanism, and yet we think of him as one of the key figures in discovering evolution.
But I haven’t seen evidence for the assertion that memes change through time like genes. I have seen anecdotes and examples of ideas and behaviors that have spread through a culture, but no evidence that the pattern is the same. I haven’t even seen a clear way of identifying a meme, observing it’s reproduction, or tracking its offspring. Not so much as a study on the change of frequency of memes in an isolated population. Memetics today has less evidence than Darwin did when he started out; at least Darwin could point to discrete entities that were changing.
Without this sort of evidence, all the concept of a meme gives me is that ideas and behaviors can get transmitted, and that they can change. And I don’t need a new concept for that. Every now and then I’ll run a search on memetics just to see if anyone’s tried to address these problems — after all, a model describing how the frequency of ideas change in a population could be extremely useful to me — but so far I’ve seen nothing, and I don’t usually have the time to run a truly thorough search.
If any of you have, and if you know of evidence for the concept, please send me a link.