On: Genetic Algorithm Walkers

[lukev]

One interesting thing is that progress very much happens by fits and starts, as it waits for the "lucky mutation" that will enable evolution to continue.

For example,

  0	Bedaaa Ceeici	6.07
  1	Bocodo Bidobo	105.93
  3	Aibebe Docoeo	107.74
  7	Diaebe Eocoeu	107.88
  10	Ciaabe Eocoeo	107.95
  25	Diaebe Facodu	108.19
  28	Biaebe Eocoeo	108.20
  30	Biaeae Eacoeo	108.47
  35	Beaebi Fucieo	109.88
  36	Biaebi Eucici	203.60
  42	Biaibi Fuceci	204.65
  45	Aiaibi Fuceeo	206.30
  47	Aiaibi Fucici	206.60
  48	Aeaebe Eoceeo	412.96
  56	Beaebe Euceeo	414.05
  59	Beaebi Fubiei	415.76
  73	Beaebi Focieu	519.01
  75	Beaebi Eocido	519.39
  96	Baaebi Gidido	521.00
  99	Baaebe Focedo	627.14

There are pretty massive jumps at generation 36, 48, 73 and 99.

By the way, this is at 50% mutation probability and 25% mutation amount. It got stuck way earlier with large less frequent mutations (as one would expect, if the probability of a beneficial mutation occurring is the limiting factor).

[fivedogit → lukev]

This is called punctuated equilibrium. Evolution happens in fits and starts after periods of relative non-change.

http://en.wikipedia.org/wiki/Punctuated_equilibrium

[im3w1l → fivedogit]

If you look at how the scores for the walkers increase as they walk, you will see that it jumps in increments of 100. I guess it is some kind of "milestone bonus".

[codys → im3w1l]

The page says "bonus points are given for each proper step forward".

So it appears they are optimizing for whatever their idea of a "proper step" is.

[rednuht → codys]

That's every time the legs switch places. Without that bonus, you'd get a lot of QWOP-ish individuals dragging one foot behind. :)