Natural Selection in Minecraft

I made a simple contraption to demonstrate natural selection on a small scale with three variables. Each sheep is made with the same variable values as its parent, plus or minus one. Each sheep has a 20% chance of reproducing every cycle, and also has a chance to be killed based on its predation chance variable. Lower predation chance means less chance of being killed. Food rate is how much food each sheep consumes per cycle, and the amount it gets might not be enough so that it dies. Life time is how many cycles each sheep will survive maximum, but i can be killed by random chance before then or run out of fod due to overpopulation. Its a really basic concept, that can be easily simulated even in Minecraft. If you want to see it in action, download it, and use the color code and time control buttons to visualize what is going on.