The selection pressures that have shaped the evolution of complex traits in humans remain largely unknown, and in some contexts highly contentious, perhaps above all where they concern mean trait differences among groups. To date, the discussion has focused on whether such group differences have any genetic basis, and if so, whether they are without fitness consequences and arose via random genetic drift, or whether they were driven by selection for different trait optima in different environments. Here, we highlight a plausible alternative, that many complex traits evolve under stabilizing selection in the face of shifting environmental effects. Under this scenario, there will be rapid evolution at the loci that contribute to trait variation, even when the trait optimum remains the same. These considerations underscore the strong assumptions about environmental effects that are required in ascribing trait differences among groups to genetic differences.
Failure of the fittest: limits on asexual adaptation to changing environments
Univ. Brest, CNRS UMR 6205, Laboratoire de Mathematiques de Bretagne Atlantique（布雷斯特大学）；BioSP, INRAE（法国国家农业食品与环境研究院）；Department of Ecology & Evolutionary Biology, University of Toronto（多伦多大学）
Two waves of adaptation: speciation induced by dormancy in a model with changing environment
Institute of Mathematics, BOKU University（博库大学数学研究所）；School of Mathematical and Statistical Sciences, Arizona State University（亚利桑那州立大学数学与统计科学学院）；Department of Mathematics, University of California San Diego（加州大学圣地亚哥分校数学系）
