Apr 27, 2010

Evolution is Not Optimal Solution?

While reading about Evolutionarily Stable Strategies (ESS), I came across an example... and then I got to thinking...

Background:  One species with 2 members, with differing traits
(Points corresponding to action performed in parenthesis)
  1. Hawks - behave aggressively
    • If opponent runs, eat food (+50)
    • If opponent fights back, they will fight to near-death
      • 1 always wins (+50), 1 always loses (-100)
  2. Doves - behave submissively
    • If attacked, will run away (+0)
    • If not attacked, will make threatening display
      • 1 always wins (+40), 1 always loses (-10)

Scenario 1 - Doves Only
  • Average of 15 points per confrontation to each member
  • However, susceptible to Hawk mutation
    • One Hawk will receive 50 points per encounter
    • More food will result in increased Hawk population

Scenario 2 - Hawks Only
  • What if Hawks take over?
  • Average of -25 points per confrontation to each member (DISASTER)
  • Population would go extinct (Fighting is costlier than the food)

Scenario 3 - Equilibrium
  • 5:7 Dove to Hawk ratio
  • Stable population balance
  • Average of 6.25 points per confrontation to each member

Why is this so interesting?

The real world is probably closer to Scenario 3 than Scenario 1.  However, Scenario 1 is BY FAR, the better world to live in (15 points vs 6.25 points).  Evolution led us to where we are, but quite likely there are better ways to improve life in our communities through concerted efforts to 1) cooperate, and 2) resist the urge to act in our own self-interest at the expense of others - Love Thy Neighbor

Note:  if the doves decide to make no threatening display, the expected value (per member, per encounter) would increase from 15 to 20 - Ninth Commandment (You shall not bear false witness against your neighbor)


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