title: Baldwin effect under multipeaked fitness landscapes: phenotypic fluctuation accelerates evolutionary rate.
abstract: Phenotypic fluctuations and plasticity can generally affect the course of evolution, a process known as the Baldwin effect. Several studies have recast this effect and claimed that phenotypic plasticity accelerates evolutionary rate (the Baldwin expediting effect); however, the validity of this claim is still controversial. In this study, we investigate the evolutionary population dynamics of a quantitative genetic model under a multipeaked fitness landscape, in order to evaluate the validity of the effect. We provide analytical expressions for the evolutionary rate and average population fitness. Our results indicate that under a multipeaked fitness landscape, phenotypic fluctuation always accelerates evolutionary rate, but it decreases the average fitness. As an extreme case of the trade-off between the rate of evolution and average fitness, phenotypic fluctuation is shown to accelerate the error catastrophe, in which a population fails to sustain a high-fitness peak. In the context of our findings, we discuss the role of phenotypic plasticity in adaptive evolution.
authors.affiliation: Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Tokyo 153-8902, Japan. saito@complex.c.u-tokyo.ac.jp
authors.forename: Nen
authors.initials: N
authors.lastname: Saito
authors.forename: Shuji
authors.initials: S
authors.lastname: Ishihara
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Kaneko
mesh_terms: D000818:Animals; D003198:Computer Simulation; D017753:Ecosystem; D019143:Evolution, Molecular; D056084:Genetic Fitness / Q000235:genetics*; D005828:Genetics, Population; D006801:Humans; D008957:Models, Genetic; D015233:Models, Statistical