The lifeless earth was dominated by a handful of basic molecules. […] Each of these molecules was capable of a finite series of transformations and exchanges with other molecules in the primordial soup. […] Think of all those initial molecules, and then imagine all the potential new combinations that they could form spontaneously. […] If you could play God and trigger all those combinations, you would end up with most of the building blocks of life: the proteins that form the boundaries of cells; sugar molecules crucial to the nucleic acids of our DNA. […] Basic fatty acids will naturally self-organize into spheres lined with a dual layer of molecules. […] Once the fatty acids combine to form those bounded spheres, a new wing of the adjacent possible opens up, because those molecules implicitly create a fundamental division between the inside and outside of the sphere. This division is the very essence of a cell. Once you have an “inside,” you can put things there: food, organelles, genetic code. […] When the first fatty acids spontaneously formed those dual-layered membranes, they opened a door into the adjacent possible that would ultimately lead to nucleotide-based genetic code, and the power plants of the chloroplasts and mitochondria—the primary “inhabitants” of all modern cells. The same pattern appears again and again throughout the evolution of life. Indeed, one way to think about the path of evolution is as a continual exploration of the adjacent possible.
Steven Johnson, Where Good Ideas Come From: The Natural History of Innovation