Evolution may be the mysterious "antientropic force" that generates complexity, at least in the living world and, just perhaps, in the universe at large. (Although, of course, evolution is not a force at all.)
The evolving biosphere and econosphere have both exhibited astonishing increases in diversity and complexity over time. One common biological ancestor diversified, we believe, into the millions of species we see today. Except for some extinction events, the diversity of species shows a steady increase.
Similarly, the diversity of goods and production capacities 50,000 years ago across the globe might have been a few thousand. Now this diversity numbers in the billions.
Why does this diversity increase?
One view is that this process is just a "random branching, birth and death process." Here is the theory: consider a token "person" on an infinite-square lattice. At each discrete moment in time he takes one step north, and at random chooses to go one step east or one step to the west. This process iterates and the "person" performs a random walk, a well-studied stochastic process. Now let the single "person," divide occasionally into two "persons" at the same spot on the lattice. Call it a "birth process." Thereafter each "person" walks fully independently of the other. From time to time there are similar "birth" processes to "persons" walking. Now add "deaths" where "persons" die and disappear from the lattice. This is a random branching, birth and death stochastic process, well studied.
On average, if births happen more frequently than deaths, the ensemble of persons will branch out on the graph in increasing numbers.
This model is commonly in mind when considering the increase in the diversity of species, economic goods and production capacities.
I think this view is deeply inadequate, if partially true.
Instead, I want to suggest that biological and economic evolution are self-creative, supracritical and progressive.
The heart of what I wish to say of organisms and businesses is that they both maintain their structure, evolve and literally create empty "Adjacent Possible" biological or economic niches. These new empty spaces are places where new organisms or businesses can come into existence.
Life confronts us with something totally novel: its evolution is self-creative. It creates new niches without selection or intent. This process can be supracritical and progressive in its diversifying complexity.