Nothing defines our use of the internet as clearly as the concept of the meme (pronounced “meem”).

Every day, millions of people laugh at LOLcats, dog shaming, and music videos without music, while others mock injustice, support marriage equality, poke fun at NSA surveillance, or call out racism.

Virally shared “nuggets of cultural currency” such as these are examples of “memetics”, an important mechanism of meaning that pre-dates the internet but is now central to the the internet’s rising creative comment culture.

The term “meme” comes from evolutionary biologist Richard Dawkins. For Dawkins, cultural ideas were no different than genes—concepts that had to spread themselves from brain to brain as quickly as they could, replicating and mutating as they went. He called those artifacts memes, bits of cultural DNA that encoded society’s shared experiences while also constantly evolving.

But Dawkins coined the term in 1976, in his book The Selfish Gene, long before the modern internet, before memes morphed into what they are now. Back then, Dawkins was talking about passing along culture—song melodies, art styles, whatever. Today, denizens of the internet think of memes as jokes passed across social media in the form of image macros (those pictures of babies or cats or whatever with bold black-and-white words on them), hashtags (the thing you amended to what you just wrote on Twitter), GIFs (usually of a celebrity, reality star, or drag queen reacting to what you just wrote on Twitter), or videos (that Rick Astley video people used to send you).