Scientist Stuart Kauffman coined the term "adjacent possible" to describe the limited range of changes available to something in its existing state.
The idea was popularized by author Steven Johnson in his book Where Good Ideas Come From. Johnson recently named his newsletter after it and writes:
In any system that is evolving over time—whether it’s a biological system or a cultural one—at any given point in that evolution, there are a finite set of ways that the system can be changed, and a much larger set of changes that can’t be made.
Single celled organisms had to evolve to become multicellular before something like a fish or chimp could exist.
The internet was science fiction until the computers that needed to be networked were invented.
And if you have dreams of running a marathon in under four hours someday, you'll need a lot of experience at shorter distances first before that becomes feasible.
The adjacent possible goes hand in hand with Gall's Law, which states that any complex system evolved from a simpler one. This is one of the reasons why the US failed in Afghanistan, for example. A government, and the economy it supports, is too complex a system to be implemented top-down. It has to incrementally grow from something simpler.
So if you're trying to scale an organization, embark on personal development, or invent something new, remember that trying to skip over the adjacent possible is setting yourself up for failure.
Like a pyramid of cards, if you're lacking one of the interdependencies at a lower level, the whole system will crumble to the ground.