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.新环境适应性的基因组基础，是演化生物学领域的核心问题之一；在当前全球变化议题备受关注的背景下，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（实验演化，experimental evolution）与全基因组DNA混样下一代测序（Pool-Seq），旨在筛选出在新型实验室环境中具有适应性优势的等位基因，并追踪其在适应性演化过程中的频率轨迹。仅历经15代繁育后，我们便检测到显著的基因组选择响应信号：近5000个单核苷酸多态性（SNP，全基因组错误发现率<0.005%）的频率偏离了中性演化预期。值得注意的是，受选择等位基因的演化轨迹呈现显著异质性，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；其二为初始阶段快速增长，随后频率趋于平稳的等位基因。综上，本研究数据表明，选择作用引发的基因组响应可涉及大量受选择SNP，其演化轨迹却呈现出远超预期的复杂性，这一现象或由非加性效应所导致。