Scheiner Samuel M, Barfield Michael, Holt Robert D
Division of Environmental Biology National Science Foundation Arlington VA USA.
Department of Biology University of Florida Gainesville FL USA.
Ecol Evol. 2017 Sep 18;7(21):8788-8803. doi: 10.1002/ece3.3429. eCollection 2017 Nov.
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.
我们使用了一个基于个体的模拟模型，来检验表型可塑性在持续存在以及适应两种环境变化模式（单一的、突然的阶跃变化和持续的、线性变化）方面所起的作用。我们的模型检验了遗传同化理论的假设和预测，探索了鲍德温效应的进化动态，并给出了对气候变化进化响应的预期。我们发现，最初假设的遗传同化不太可能发生，因为由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长得多。另一方面，只要可塑性几乎没有或没有成本，作为对持续进化变化的增强的性状可塑性，可能是一种重要的进化机制。在环境发生阶跃变化后，可塑性是有助于还是阻碍进化拯救，取决于可塑性是否有成本。对于线性环境变化，无成本的可塑性总是会降低灭绝率，而有成本的可塑性会造成适应性拖累并增加灭绝的可能性。因此，随着气候的变化，在某些条件下可塑性可以增强适应性并防止灭绝，但在其他条件下则不然。
