Data from: Does phenotypic plasticity for adult size versus food level in Drosophila melanogaster evolve in response to adaptation to different rearing densities?

Recent studies using inbred lines of Drosophila have suggested that there is extensive genetic variability for phenotypic plasticity of body size versus food level. If true, we expect that the outcome of evolution at very different food levels should yield genotypes whose adult sizes show different patterns of phenotypic plasticity. We have tested this prediction with six independent populations of Drosophila melanogaster kept at extreme (low vs. high) densities for 125 generations. We found that the phenotypic plasticity of body size versus food level is not affected by selection or the presence of competitors of a different genotype. However, we document increasing among population variation in phenotypic plasticity due to random genetic drift. Several reasons are explored to explain these results including the possibility that the use of highly inbred lines to make inferences about the evolution of genetically variable populations may be misleading.过往采用果蝇（Drosophila）近交系开展的研究表明，体型对食物水平的表型可塑性（phenotypic plasticity）存在广泛的遗传变异。若该结论成立，则可预期：在差异悬殊的食物水平下发生的演化过程，将产生成年体型具有不同表型可塑性模式的基因型。本研究以在极端（低vs高）种群密度下连续饲养125代的6个独立黑腹果蝇（Drosophila melanogaster）种群，对上述预测进行了验证。研究发现，体型对食物水平的表型可塑性并未受到选择作用或异种基因型竞争者存在的影响。但我们观测到，由于随机遗传漂变（random genetic drift），种群间的表型可塑性差异逐渐增大。本研究探讨了多种可解释该结果的潜在原因，其中包括：采用高度近交系来推断遗传变异种群的演化规律，可能会得出误导性结论。