Extending the Alife metaphor

1
Extending the Alife metaphor

• Eric Dimperio
• 1/31/2005

2
Overview

• Tierra quirks and challenges
• Darwin's postulates
• Planes, trains, and automobiles
• Urban legends
• Cha-ching

3
Evolution is hard to stop

• Tierra allows evolutions even when all mutation
  is stopped
• Sloppy Replicators
• System Errors
• The Reaper
• What other ways can variability be introduced
  other than mutation and sexual reproduction?

4
Is self-replication necessary?

• Self-replication is critical to synthetic life
  because without it, the mechanisms of selection
  must also be pre-determined by the simulator.
  Such artificial selection can never be as
  creative as natural selection. The organisms are
  not free to invent their own fitness functions.
  - Tom Ray
• What about viruses?
• Doesn't natural selection still succumb to some
  grand fitness function?

5
A-life Tautology

• That which survives, persists.
• That which reproduces, increases its numbers.
• Things change.

6
Darwin's Postulates

• More individuals are produced than can survive
• Variation among individuals
• Variable traits are inherited
• Variable traits affect an individual's chances
  for survival and reproduction

7
Cha-Ching

• Essays on Genetic Evolution and Economics
  (Burnham, T. 1997)
• Evolutionary Economics
• http//www.business.aau.dk/evolution/
• Nelson and Winter
• Evolutionary Theory of Economic Change (1982)
• Kwasnicki and Kwasnicka
• http//prawo.uni.wroc.pl/kwasnicki/e-model.htm

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Industrial dynamics

• Kwasnicki and Kwasnicka
• Firms producing similar products are defined by a
  genotype. These are policies regulating price,
  RD, investmenst, modernization of product, etc.
• Variability is introduced by
• mutation (moderate modification) - autonomous
  research, in-house development
• recombination, imitation
• transition
• transposition
• recrudescence - search for radical novelty
  through reshaping of the active set of routines
  (large number of transpositions and/or frequent
  modifications by means of mutation)

9
Software tools

• Laboratory for Simulation Development (lsd)
• Maple
• MEGA (Molecular Evolutionary Genetics Analysis)
  for phylogenetics
• Sugarscape
• SWARM

10
Planes, Trains, Automobiles

• More individuals are produced than can survive
• Variation among individuals
• Technology, materials, style
• Variable traits are inherited
• Incremental changes of old models
• New models that 'borrow' from old
• Variable traits affect an individual's chances
  for survival and reproduction
• trends