The genetics of phenotypic plasticity. XV. Genetic assimilation, the Baldwin effect, and evolutionary rescue
The genetics of phenotypic plasticity. XV. Genetic assimilation, the Baldwin effect, and evolutionary rescue
复制标题
表型可塑性的遗传学。
作者：
S. Scheiner;M. Barfield;R. Holt
摘要：我们使用基于个体的模拟模型来研究表型可塑性对两种环境变化模式（单一突变阶跃变化和连续线性变化）的持久性和适应的作用。我们的模型检验了遗传同化理论的假设和预测，探讨了鲍德温效应的进化动力学，并为气候变化的进化反应提供了预期。我们发现，最初假设的遗传同化不太可能发生，因为固定遗传效应取代可塑性所需的时间比环境可能保持稳定的时间要长得多。另一方面，只要可塑性的成本很少或没有，性状可塑性作为持续进化变化的增强可能是一种重要的进化机制。可塑性是否有助于或阻碍环境发生阶跃变化后的进化救援，取决于可塑性的成本是否昂贵。对于线性环境变化，无成本的可塑性总是会降低灭绝率，而昂贵的可塑性会产生适应性阻力并增加灭绝的机会。因此，随着气候的变化，可塑性可以在某些条件下增强适应并防止灭绝，但在其他条件下则不然。
Abstract We used an individual‐based simulation model to examine the role of phenotypic plasticity on persistence and adaptation to two patterns of environmental variation, a single, abrupt step change and continual, linear change. Our model tested the assumptions and predictions of the theory of genetic assimilation, explored the evolutionary dynamics of the Baldwin effect, and provided expectations for the evolutionary response to climate change. We found that genetic assimilation as originally postulated is not likely to occur because the replacement of plasticity by fixed genetic effects takes much longer than the environment is likely to remain stable. On the other hand, trait plasticity as an enhancement to continual evolutionary change may be an important evolutionary mechanism as long as plasticity has little or no costs. Whether or not plasticity helps or hinders evolutionary rescue following a step change in the environment depends on whether plasticity is costly. For linear environmental change, noncostly plasticity always decreases extinction rates, while costly plasticity can create a fitness drag and increase the chance of extinction. Thus, with changing climates plasticity can enhance adaptation and prevent extinction under some conditions, but not others.