Can someone please explain what the graph is? I can't quite figure it out. I'm assuming that the green is total distance traveled... but I can't figure out what the black one means.
For each iteration there are 20 individuals. Each gets a score according to how far they get. The horizontal line is the generation. The black line shows the best in each generation, and green line shows the average over the 20 individuals in that generation.
The black line is always above the green, but sometimes crashes way down. The green line doesn't change dramatically, and generally climbs.
There is a great discussion of this (and a further mapping of fitness functions and evolutionary algorithms to a 2-dimensional "fitness landscape") in The Origin of Wealth by Eric Beinhocker - http://www.amazon.com/Origin-Wealth-Evolution-Complexity-Eco...
Absolutely phenomenal exploration of complexity economics.
Nope it's a lot simpler than that as said above. Basically the x axis is generation, y axis is distance. The black line is the max and the green line is the average.