Data from: Adaptation of Drosophila to a novel laboratory environment reveals temporally heterogeneous trajectories of selected alleles

The genomic basis of adaptation to novel environments is a fundamental problem in evolutionary biology that has gained additional importance in the light of the recent global change discussion. Here, we combined laboratory natural selection (experimental evolution) in Drosophila melanogaster with genome-wide next generation sequencing of DNA pools (Pool-Seq) to identify alleles that are favourable in a novel laboratory environment and traced their trajectories during the adaptive process. Already after 15 generations, we identified a pronounced genomic response to selection, with almost 5000 single nucleotide polymorphisms (SNP; genome-wide false discovery rates < 0.005%) deviating from neutral expectation. Importantly, the evolutionary trajectories of the selected alleles were heterogeneous, with the alleles falling into two distinct classes: (i) alleles that continuously rise in frequency; and (ii) alleles that at first increase rapidly but whose frequencies then reach a plateau. Our data thus suggest that the genomic response to selection can involve a large number of selected SNPs that show unexpectedly complex evolutionary trajectories, possibly due to nonadditive effects.适应新型环境的基因组基础是进化生物学的核心研究问题，而随着近期全球变化相关议题的讨论升温，该问题的研究价值进一步凸显。本研究结合黑腹果蝇（Drosophila melanogaster）的实验室自然选择（实验进化）体系与DNA混池全基因组下一代测序（Pool-Seq）技术，鉴定新型实验室环境中具有适应性优势的等位基因，并追踪其在适应过程中的频率动态轨迹。仅历经15代培养后，研究团队便观测到显著的基因组选择响应：近5000个单核苷酸多态性（SNP）的频率偏离中性预期，其全基因组错误发现率低于0.005%。值得注意的是，受选择等位基因的进化轨迹存在显著异质性，可分为两类截然不同的模式：其一为频率持续上升的等位基因；其二为初期快速增长后趋于频率平稳的等位基因。综上，本研究数据表明，选择作用下的基因组响应可涉及大量受选择的单核苷酸多态性，其进化轨迹呈现出超乎预期的复杂性，该现象可能由非加性效应所致。