The path of evolution is always through the adjacent possible. Every stage of evolution has to be viable, a living, breathing answer to its environment.
Each step into the adjacent possible opens up new adjacent possibilities, changing the environment, and what is possible, what is viable. Stepping stones in possibility space.
See also: Gall’s law
“You can’t build railroads before it is railroad time.” (Chuck Thacker)
Link to original
Evolution by natural selection only works if each mutational step itself is advantageous. There’s no such thing as advantageous in a general sense. It’s advantageous in the circumstances you’re living in. (Olivia Judson, 2019. Complexity Podcast.)