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Fitness Causes Bloat

  1. Search starts with short trial progs  
  2. Rate of improvement quickly falls  
  3. Fitness selects best in population  
  4. 2. & 3. Fitness selects children which behave like their parents  
  5. There are many more long programs than short which behave the same  
  6. 1. & 4. & 5. Selecting one at random is likely to be longer than its parent
    I.e. Fitness causes bloat



William B Langdon
Thu May 14 11:09:24 BST 1998