Allele is a very important concept represented by a terribly unpopular word. If you compare allele with gene in a search engine duel, you will probably see that "gene" outnumbers "allele" over 30:1. Even after you adjust for usage of "gene" as a name, the result is still a landslide against "allele".
If you look at the usages of the term "gene" you will find that many of them use the term to mean "allele". Indeed, if you compare search volumes for:
- "gene for blue eyes" with "allele for blue eyes" - the former wins 4:1;
- "gene for tongue" with "allele for tongue" - the former wins 3:1;
- "tongue rolling gene" with "tongue rolling allele" - the former wins 23:1;
- "gene for hairy ears" with "allele for hairy ears" - the former wins 100:1.
"Gene" is more popular than "allele" - even in the cases where "allele" is technically more correct.
Problems with "allele" adoption include issues with pronouncing and spelling it, and the possibility that your audience will not understand the term.
Memetics imported the "gene-as-allele" meaning without blinking. Whenever you see "meme", usually it refers to an "allomorphic meme", or a "meme instance". There are "allomemes". However, that term is even less frequently used, with only 277 hits on the whole internet at the time of writing. If "alleles" had been called "genestances" there could have been "memestances" - but that terminology is not from this universe.
The term "allele" has done so poorly, that I think the best thing to do at this stage is ditch it. It is easy to switch to the term "gene" to describe "allele" - since the majority regularly use the term "gene" that way anyway. There will be a few anal-retentive types who will say "don't you mean allele?". Now those folk can be directed to this page.
Providentially, there's already a term for the spot which alleles compete over - a "locus". You can have a "genetic locus", and a "memetic locus" (e.g. "red", "rouge", "rot" and "rojo" compete for the same memetic locus) - so the concept is portable to memetics. A particular locus could be called a "gene locus" - or a "meme locus". Those concepts are all longer than "gene" or "allele" - but they do have the virtue of being pretty self-explanatory, and often the context will be clear enough to just say "locus".
The term "allele" can be ditched unilaterally, without much explanation being needed. The ditchers of the "allele" term might sometimes pay a small cost - in that sometimes readers will think: "(s)he probably means allele - does this chap know what (s)he is talking about?" This seems to be endurable to me, killing off terminology often has some associated costs.
One objection is that this involves more heavily overloading the term "gene". However, the term "gene" is already being overloaded in exactly this way - simply through popular usage. Ditching "allele" would pave the way towards ditching the old meaning of "gene" and promoting the term into what popular usage has made of it.
"Allele" may die hard, partly since using it signals being an expert. However, in this post, I am putting the boot in. If you agree, please feel free to engage in some public allele-trashing.