When I was 12 or so, I read about John Horton Conway’s cellular automaton Life in Scientific American. Back then (c. 1970) we had to painfully draw each generation on graph paper. The personal computer revolution made it possible for hobbyists and students to simulate large fields and thousands of generations easily, building self-replicating structures and Turing machines… Life could simulate life.
Later in my career, I wrote artificial life simulations similar to what is portrayed in Red Queen — these are an extension to simulation of creatures in a simulated environment. There is a progression as simulations get better and better — eventually the simulation of life in an environment can become as complex as the real world, which has led to current theories that the universe we live in may itself be some kind of simulation on an underlying substrate.
The video below is an amazing zoom from tiny gliders to glider guns to megastructures… and then to Life itself simulated by Life.