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Showing posts from February, 2024

The Evolution of Cooperation

The Tragedy of the Commons occurs when a group’s individual incentives lead them to take actions which, in aggregate, lead to negative consequences for all group members. It is a multi-player version of the Prisoner’s Dilemma. In the version of the game from which it got its name, the players are two prisoners, held in separate cells. Each has to choose between “cooperating” with the other (keeping quiet) or “defecting” (giving evidence against the other). Each makes the choice without knowing what the other will do. If both prisoners keep quiet, they are each sentenced to one year in prison. If one rats on the other, he or she goes free and the other gets 10 years. If they both rat on each other, they each get 5 years. The problem arises because whatever your opponent does, defecting gives you a higher payoff than cooperating.  In 1984 Robert Axelrod published a book called The Evolution of Cooperation, which contained a surprising reflection: if you play a Prisoner’s Dilemma game, n


In Denmark the remains of Early Neolithic settlements on the banks of the lake have been preserved. The bog has good preservation conditions for animal bones and plant remains. The pollen from the bog strata shows how the vegetation changed after the arrival of the farmers, c. 4000 BC. Tree pollen was superseded by grain pollen and herb pollen when primeval forest was transformed into arable land.