Evolving Creatures

Each creature is a handful of masses joined by springs, and some springs are muscles that push and pull on a rhythm set by that creature's genome. All of them race to the right at once. When the clock runs out, the farthest travelers breed with a little mutation and the next generation starts. It is a toy genetic algorithm, and it is usually enough to turn wobbling blobs into steady runners. You can also build your own creature from dots and edges and let evolution figure out how to drive it. You design the body; evolution finds the rhythm. Inspired by Karl Sims' Evolved Virtual Creatures (1994). All code here is original.