In the HN thread, someone asked "how are genetic (algorithms) used?", which is what I'm wondering too. The creator says:
so, i just used them like conceptually..
each boid has a string, when boids come close , they produce a offspring with mixed string + mutation age lets boids die too
nothing fancy, just for sake of sim
If you're unfamiliar with Boids, it's an algorithm that's been around for a while, and simulates flocking like you see in birds pretty well:
https://en.wikipedia.org/wiki/Boids
Can't remember where I saw someone do this, but applying the algorithm to humans in games gives you a very zombie-like behavior.