Saito Nen, Ishihara Shuji, Kaneko Kunihiko
Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Tokyo 153-8902, Japan.
Phys Rev E Stat Nonlin Soft Matter Phys. 2013 May;87(5):052701. doi: 10.1103/PhysRevE.87.052701. Epub 2013 May 2.
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.
表型波动和可塑性通常会影响进化进程，这一过程被称为鲍德温效应。多项研究重新诠释了这一效应，并声称表型可塑性会加速进化速率（鲍德温加速效应）；然而，这一说法的有效性仍存在争议。在本研究中，我们研究了在多峰适应度景观下定量遗传模型的进化种群动态，以评估该效应的有效性。我们给出了进化速率和平均种群适应度的解析表达式。我们的结果表明，在多峰适应度景观下，表型波动总是会加速进化速率，但会降低平均适应度。作为进化速率与平均适应度之间权衡的一个极端情况，表型波动被证明会加速错误灾难，即种群无法维持在高适应度峰值。结合我们的研究结果，我们讨论了表型可塑性在适应性进化中的作用。
