Stochasticity in evolution.
The debate over the role of stochasticity is central in evolutionary biology, often summarised by whether or not evolution is predictable or repeatable. Here we distinguish three types of stochasticity: stochasticity of mutation and variation, of individual life histories and of environmental change. We then explain when stochasticity matters in evolution, distinguishing four broad situations: stochasticity contributes to maladaptation or limits adaptation; it drives evolution on flat fitness landscapes (evolutionary freedom); it might promote jumps from one fitness peak to another (evolutionary revolutions); and it might shape the selection pressures themselves. We show that stochasticity, by directly steering evolution, has become an essential ingredient of evolutionary theory beyond the classical Wright-Fisher or neutralist-selectionist debates.
Lenormand
Thomas
T
Centre d'Ecologie Fonctionnelle et Evolutive, UMR 5175, 1919 Route de Mende, Montpellier cedex 5, France. thomas.lenormand@cefe.cnrs.fr
Roze
Denis
D
Rousset
François
F
D000220:Adaptation, Biological; D005075:Biological Evolution; D004777:Environment; D040961:Genetic Drift; D014644:Genetic Variation; D009154:Mutation; D011157:Population Dynamics; D012641:Selection, Genetic; D013269:Stochastic Processes; D013816:Thermodynamics