Users, snoozers, and losers: Evolutionary implications of fungal behavior.

The Baldwin effect is an important theoretical mechanism in evolutionary theory in which beneficial mutations follow the adoption of new behavioral adaptations in animals. This model has not been applied to fungi and other microorganisms because they cannot transmit behavioral routines between individuals within a population before they are encoded genetically. Nevertheless, a version of the Baldwin effect may drive the evolutionary trajectories of the fungi when individual mycelia make choices as they grow and branch in different directions. Through these displays of phenotypic plasticity or individuality some mycelia produce more offspring than others and will thereby stabilize post hoc mutations that favor specific mycelial geometries in response to environmental pressure.