Angry letters respond to a review article in Science which suggested that cooperative game theory is a better model of reproduction than Darwin's sexual selection. (by Nick Atkinson)

A certain bacteria-eatring virus plays the prisoner's dilemma, with "cheat" a substantial proportion evolving to play "cheat." (by Paul E. Turner)

An evolutionary take on public goods contribution experiments, in which subject populations may converge to mixed strategies

Colonies of generally competitive ants have been found with a genetic mutation that turns off competitiveness and allows for large-scale cooperation (by Ingrid Sanders)

The finding that monkeys have an innate sense of fairness may mean that altruism may be quite rational.

A (dubious) study finds that a species of monkeys has an innate sense of fairness. Perhaps the monkeys should have played an ultimatum game.

In the evolutionary mating game, experienced partners of a number of species prefer weaker males, potentially as a signal of less abuse to come.

One researcher suggests a hormonal cause of good will in games and an inverse link between religion and altrusim. (by Ken Grimes)

When species coevolve, the one that adapts slower effectively commits and may be better off.

Blue Jays trained to play the prisoner's dilemma appear to adopt a tit-for-tat strategy, leading to cooperation.

Describes evidence of Amotz Zahavi's "handicap principle" by which risky, extravangant behaviors by many species of animals signal strength and ability.

Trees signal defenses to insects.

Trees signal defenses to insects.

Laying a final pale egg deters free riding "egg dumpers" by signaling that incubation has begun.

Multiple mating strategies survive in the mixed-strategy equilibrium

Multiple mating strategies survive in the mixed-strategy equilibrium

Examines cooperation in extensive-form games on the TV show "Survivor."

Evolutionary biologist George Pierce believed in the evolution of cooperation

Primitive phages, bacteria-infecting viruses, play the prisoner's dilemma on a genetic, evolutionary level.

Evolutionary game theory explains how animals react to meeting a rival from the same species face to face. (by Mike Mesterton-Gibbons and Eldridge S. Adams)

Can cooperation in prisoner's dilemma -type games evolve without repeated interaction, through indirect reciprocity?

Describes the use of tit for tat throughout the natural world and notes Axelrod's findings.

Poisonous frogs adopt different behaviors than their nonpoisonous kin, including brighter colors and dayime activity. (by Verne G. Kopytoff)