The idea has always attracted me! Create an environment (model it somehow, in a programming language). Define some life form (model their replication, mating, dying etc.) then let them live! Even could model a crypto into it, in order to test how it will be distributed 
The more complex their behavior, the more chaotic will the outcome be. But imagine one of these life forms continue to live! How would you feel, as their creator! 
The more complex their behavior, the more chaotic will the outcome be. But imagine one of these life forms continue to live! How would you feel, as their creator!
That already exists - it's called the Game of Life.
Basically, you die from overpopulation or loneliness, otherwise you have a chance to multiply.
http://www.d.umn.edu/~weis0258/cs2121/GameOfLife.html
https://www.kongregate.com/games/locos/the-game-of-life