Where New Adaptations Come From

 I posted a video in which I explain where new evolutionary adaptations, and cultural innovations, come from. I filmed the video in Strasbourg, which has many old villages crammed together, such as Hoenheim (where I live) and Bischeim and even one called Souffelweyersheim.

Here is how I learned the process of natural selection. A new mutation appears, then if it is a good one, natural selection favors it. It starts off very rare—only one individual carries it—and ends up common, maybe even going to fixation (completely replacing the other versions of the gene). This is the way I taught it, and the way I wrote about it in my Encyclopedia of Evolution.

But the reality is more complicated, as is usually the case in science. If the mutation appears in a large population, say, a million organisms, then it is extremely rare—one in a million. No matter how good it is, it can get lost by random events before it has a chance to get selected. It has virtually no chance.

But suppose the large population, a million individuals, consists of small interconnected populations, maybe a hundred each. If the mutation occurs in one of them, it has a chance of becoming common, maybe even going to fixation. One chance in a hundred. Then if it spreads to another population, it has another one chance in a hundred to go to fixation. If this happens a hundred times, the new mutation now has ten thousand chances out of a million to be successful.

This is the shifting balances theory of Sewall Wright, who was one of the most important figures in the modern theory of evolution. He was publishing books right up until his death almost at age 100. New adaptations get started in small populations. That is the only way they have a ghost of a chance of succeeding. This is how natural selection must work.

Cultural evolution works the same way, but with ideas instead of genes. Suppose somebody got a great new idea in Hoenheim (or even Souffelweyersheim!). In a small village, the idea might have a chance to spread. If it becomes common in Hoenheim, it might become common in Strasbourg as well. And from there it might have a chance of success in Paris. (This may be unlikely, since Parisians consider themselves the cultural center of the universe, and Strasbourg, to them, is unspeakably provincial.) And from Paris, maybe the world. But the new idea popping up in Paris would get swamped out by all the other ideas in Paris.

This is not the whole story because, of course, Paris consists of lots of small populations, local neighborhoods and arrondissements. A big new idea in the 49^th arrondissement might spread to the 5^th.

One of the major examples of a cultural innovation starting in a place considered provincial is the printing press. Johannes Gutenberg perhaps had to start in an out of the way place—in fact, it was Strasbourg, where I now live. He did not start in Paris or Vienna.