Division of Environmental Biology, National Science Foundation 4201 Wilson Blvd., Arlington, Virginia, 22230.
Ecol Evol. 2014 Feb;4(4):505-15. doi: 10.1002/ece3.951. Epub 2014 Jan 23.
One potential evolutionary response to environmental heterogeneity is the production of randomly variable offspring through developmental instability, a type of bet-hedging. I used an individual-based, genetically explicit model to examine the evolution of developmental instability. The model considered both temporal and spatial heterogeneity alone and in combination, the effect of migration pattern (stepping stone vs. island), and life-history strategy. I confirmed that temporal heterogeneity alone requires a threshold amount of variation to select for a substantial amount of developmental instability. For spatial heterogeneity only, the response to selection on developmental instability depended on the life-history strategy and the form and pattern of dispersal with the greatest response for island migration when selection occurred before dispersal. Both spatial and temporal variation alone select for similar amounts of instability, but in combination resulted in substantially more instability than either alone. Local adaptation traded off against bet-hedging, but not in a simple linear fashion. I found higher-order interactions between life-history patterns, dispersal rates, dispersal patterns, and environmental heterogeneity that are not explainable by simple intuition. We need additional modeling efforts to understand these interactions and empirical tests that explicitly account for all of these factors.
一种潜在的应对环境异质性的进化反应是通过发育不稳定产生随机变异的后代,这是一种风险分摊。我使用基于个体的、遗传明确的模型来研究发育不稳定的进化。该模型单独考虑了时间和空间异质性,以及它们的组合、迁移模式(踏脚石与岛屿)和生活史策略的影响。我证实,仅时间异质性就需要一定量的变异来选择大量的发育不稳定。对于仅空间异质性,对发育不稳定的选择反应取决于生活史策略和扩散的形式和模式,当选择发生在扩散之前时,岛屿迁移的选择反应最大。时间和空间变异性本身选择了相似数量的不稳定性,但组合起来导致的不稳定性比任何一种单独作用都要大得多。局部适应与风险分摊相权衡,但不是以简单的线性方式。我发现了生活史模式、扩散率、扩散模式和环境异质性之间的高阶相互作用,这些作用不能仅用简单的直觉来解释。我们需要额外的建模工作来理解这些相互作用,并进行明确考虑所有这些因素的实证测试。