Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada.
Genetics. 2022 Jan 4;220(1). doi: 10.1093/genetics/iyab134.
Observations about the number, frequency, effect size, and genomic distribution of alleles associated with complex traits must be interpreted in light of evolutionary process. These characteristics, which constitute a trait's genetic architecture, can dramatically affect evolutionary outcomes in applications from agriculture to medicine, and can provide a window into how evolution works. Here, I review theoretical predictions about the evolution of genetic architecture under spatially homogeneous, global adaptation as compared with spatially heterogeneous, local adaptation. Due to the tension between divergent selection and migration, local adaptation can favor "concentrated" genetic architectures that are enriched for alleles of larger effect, clustered in a smaller number of genomic regions, relative to expectations under global adaptation. However, the evolution of such architectures may be limited by many factors, including the genotypic redundancy of the trait, mutation rate, and temporal variability of environment. I review the circumstances in which predictions differ for global vs local adaptation and discuss where progress can be made in testing hypotheses using data from natural populations and lab experiments. As the field of comparative population genomics expands in scope, differences in architecture among traits and species will provide insights into how evolution works, and such differences must be interpreted in light of which kind of selection has been operating.
必须根据进化过程来解释与复杂性状相关的等位基因的数量、频率、效应大小和基因组分布的观察结果。这些构成性状遗传结构的特征，在从农业到医学的应用中，可以极大地影响进化结果，并为了解进化过程提供了一个窗口。在这里，我回顾了在空间均匀的全球适应与空间异质的局部适应下，遗传结构进化的理论预测。由于分歧选择和迁移之间的紧张关系，局部适应可能有利于“集中”的遗传结构，这些结构富含更大效应的等位基因，集中在少数基因组区域中，相对于全球适应的预期。然而，这种结构的进化可能受到许多因素的限制，包括性状的基因型冗余、突变率和环境的时间可变性。我回顾了全球适应与局部适应预测不同的情况，并讨论了在使用自然种群和实验室实验数据检验假设方面可以取得进展的情况。随着比较群体基因组学领域的扩展，性状和物种之间结构的差异将提供有关进化过程的见解，并且必须根据哪种选择起作用来解释这些差异。
