How did air-breathing evolve? In The Nature of Economies (p. 87), Jane Jacobs uses it to illustrate the developmental pattern she calls “bifurcation” (air-breathing isn’t a refinement of water-breathing). She speculates on how it started:
Lungfish had both gills and a primitive lung, suggesting that their habitat was swampland. The earliest to take to dry land may have inhabited swamps subject to severe droughts or perhaps they were escaping fearsomely-jawed predators who couldn’t follow them to dry land.
According to Steve Yegge’s already-famous “psst, Googlers” memo, something much like this was why Amazon started selling web computing services, which wasn’t a refinement of their earlier business (selling books, toys, etc.):
Amazon was a product company too, so it took an out-of-band force to make Bezos understand the need for a platform. That force was their evaporating margins; he was cornered and had to think of a way out. But all he had was a bunch of engineers and all these computers… if only they could be monetized somehow… you can see how he arrived at AWS [Amazon Web Services], in hindsight.
People say necessity is the mother of invention. That isn’t even close to true. Trial and error is the mother of true, profound invention. The Bezos story, and Jacobs’s generalization of it, suggest what is actually true: necessity is the mother of development. Necessity pushes people to use, and thereby develop, inventions they had ignored.