Genes, Memes, and the Mess of Cultural Evolution

Next to the Genome, Culture is a Mess, and Its Evolution a Much Harder Puzzle

Okay, so what are memes? This is a term invented 30 years ago by Richard Dawkins, to try to find an equivalent for genes in cultural evolution. The term is now in general usage among those who study cultural evolution, and it has a certain usefulness.

However, it’s a mess compared to the concept of gene. A gene is a discreet string of DNA (or for HIV and some other viruses, RNA) that codes for a protein or for an active piece of RNA. Genes have a beginning (a promoter), a middle (the coding part), and an end (the stop signal to indicate that protein making is done.

These were the ideal real-world match for the genes talked about for half a century, or for that matter the things envisioned by Gregor Mendel when he played around with his pea plants. They were discreet, independent, highly heritable, could be recessive or dominant, and, by making proteins, determined traits we see in ourselves and other organisms.

Unfortunately for simplicity, it was found in the nineties and since that there are very large numbers of short RNAs popping off the DNA-transcription machine that don’t resemble anything made by genes but which are critical in turning genes on and off. Vast domains of the genome which until recently were called “junk DNA” because they were thought to be do-nothing strings of “selfish” DNA that just managed to hitchhike along with respectable genes. In humans there seemed to be so much of this junk that the tail was wagging the dog (yes, this would be true of dogs too).

Enter micro RNAs, or mRNAs. These little bits of RNA bear no resemblance to the long strings that can make proteins, but they are far from do-nothings. On the contrary, the somethings they do by regulating genes and organizing the hierarchy of the genome may turn out to be the most important functions of the genome, and the ones most responsible for the differences between us and dogs, or between mammals and fish.

So the elegant idea of the genome as a collection of genes has suffered a bit, and the idea of selfish genes making up a huge junkpile in the genome is on the ropes.

But what about memes? They are and have always been much worse off than genes, even with recent changes, because the concept of meme covers so many different things. A meme can be a hula hoop or the act of swinging the hoop around your hips, a popular fad in the U.S. in the fifties. It can also be the nation’s flag or the act of saluting it. It can be a casserole recipe, a prayer, the idea of God, the Bible, the game of baseball, a fastball, sexual promiscuity or abstinence, romantic love, Mother’s Day, or war.

You get the idea. Genes are all around the same size, have similar structures, and function similarly to transcribe RNA, which generally translates into proteins, which affect a variety of traits. Memes on the other hand are all different sizes, look different, blend into each other, and are transmitted from one individual to another in totally different ways.

Nevertheless, the analogy to genes is still useful, because every meme is an aspect of culture that can be transmitted from individual to individual, including from generation to generation, and can be adaptive or maladaptive by enhancing or reducing the individual’s ability to pass it on.

I got to thinking about memes again when I read a study published last week in the New England Journal of Medicine, showing that one of the most important determinants of whether or not you smoke is whether or not your friends, relatives, coworkers, or husbands and wives smoke.

At some point I’ll write about that study and how it illustrates the cultural evolution of memes while at the same time showing the limits of the meme concept. But even compared to the increasingly messy genome, cultural evolution has nowhere near the elegance of genetic evolution, and the mathematical models used to simulate it are equally problematic.

Leave a Reply