Language evolves. New words and concepts show up and catch on—“app,” “smartphone,” “podcast”—or die from disuse or dysfunction—“Y2K,” “newsreel,” “rad.” And there’s even a word for how these concepts make their way from person to person: “meme.”

Rhyming with “cream,” the word “meme” was coined in 1976 by Richard Dawkins, an evolutionary biologist, in his book The Selfish Gene. In discussing how communications occurs, Dawkins wrote:

We need a name for the new replicator, a noun that conveys the idea of a unit of cultural transmission, or a unit of imitation. “Mimeme” comes from a suitable Greek root, but I want a monosyllable that sounds a bit like “gene.” I hope my classicist friends will forgive me if I abbreviate mimeme to meme.

Dawkins wrote, “Examples of memes are tunes, ideas, catch-phrases, clothes fashions, ways of making pots or of building arches.” In other words, fads, oral histories, things passed from person to person. Dawkins said that these “memes” are passed along and evolve similar to the way genetic material is passed along and evolves.

(In a similar fashion, the word “organic” has been repurposed to mean “occurring naturally,” even when the things that are occurring are not creatures of nature at all. It’s frequently used in the sense that one idea leads to another. Visual Thesaurus, for example, uses an “organic” method of showing the relationships between words; the connections seem to flow naturally.)

“Meme” caught on and, in a way that Dawkins probably appreciates, has become its own “meme.” Here are a few ways it has been used recently:

• A blogger complained that a dog-positive Mitt Romney story has been ignored “while the ‘Romney treats dogs like dirt’ story has grown into a clearly false yet full-blown meme.

• A writer who dislikes superheroes discussed how the rise of Marvel Entertainment “underscores how the costumed-crusader meme has conquered the entertainment industry.”

• Anonymous, the hacker group, was described as having begun “as an Internet meme in the early 2000s.” (“Internet meme” is a “meme” of its own as well.)

• Even “lolcats” are involved, as an article related: “Great Moments in Cat Memes.”

“Meme” is in vogue, though not every reader is going to know what it means. Sometimes, one just might use a more familiar word, like “story,” “genre,” “idea,” or “history.” Choosing “meme” instead of another word is not always the même chose.