Memes are as old as humanity and are intrinsically related to cultural evolution. Memes are replicators that information, how viruses infect our thoughts affect our behavior, and to propagate from brain to brain, forming our culture. So the meme is the cultural gene that reproduces.
Anything that can be learned and transmitted as a standalone unit is a meme. For example, ideas, party ideas, values, sounds, languages, words, slogans, drawings, can be memes. The doctrines and religions are formed by memes that persist for centuries. Slang are memes. The way we dress are memes.
The term "meme" was coined by Richard Dawkins in his 1976 bestseller "The Selfish Gene", and comes from the Greek word "mimeme" (which means "something that is imitated"). The book presents the idea of universal Darwinism in which not only the species, but anything evolves based on variety, selection and heredity. Thus, the meme is to culture such gene is the gene for. Humans are genetic machines and meme machines.
Importantly, a meme is not a virus, because while viral is a unit of information that spreads without modification, a meme spreads like behavior imitated. The viral meme ends in itself and can reinvent itself every edition. The viral has fidelity copy and not the meme.
And because memes spread? Some of scatter because they are useful, good-looking or because they relate to power, fear, beliefs, novelty, but other without any spread so that there is no explanation, for example, the odd meme "in freezer heads" in which people around the world began posting photos on the internet with his head inside the refrigerator, based on the number 241543903, as shown below.
