Evolutionarily labile dispersal behavior and discontinuous habitats enhance population differentiation in island vs continentally distributed swallows

The causes of population divergence in vagile groups remain a paradox in evolutionary biology: dispersive species should be able to colonize new areas, a prerequisite for allopatric speciation, but dispersal also facilitates gene flow, which erodes population differentiation. Strong dispersal ability has been suggested to enhance divergence in patchy habitats and inhibit divergence in continuous landscapes, but empirical support for this hypothesis is lacking. Here we compared patterns of population divergence in a dispersive clade of swallows distributed across both patchy and continuous habitats. The Pacific Swallow (Hirundo tahitica) has an insular distribution throughout Southeast Asia and the Pacific, while its sister species, the Welcome Swallow (H. neoxena), has a continental distribution in Australia. We used whole-genome data to demonstrate strong genetic structure and limited introgression among insular populations, but not among continental populations. Demographic models sho..., , , # Data from: Evolutionarily labile dispersal behavior and discontinuous habitats enhance population differentiation in island vs. continentally distributed swallows [https://doi.org/10.5061/dryad.18931zd3m](https://doi.org/10.5061/dryad.18931zd3m) ## Description of the data and file structure Included is a .vcf file of all samples used in the analysis filtered to have minimum depth of 5, maximum depth of 50, minimum read quality of 30, minor allele frequency of 5%, and less than 15% missing data. Outgroup samples are included. Metadata are available in Table S1 of the manuscript. The water_gaps.csv file includes the geographic distances and water gap classifications used in analyses of isolation by distance. * The first column indicates the minimum as the crow flies distance between populations in km. * The second column indicates the distance between the center of two populations in km; this is relevant only for welcome swallows, where dispersed samples from across different regio...移动类群的种群分化成因始终是进化生物学领域的一大悖论：具备扩散能力的物种本可开拓新的栖息区域，这是异域物种形成的先决条件，但扩散同时也会促进基因交流，进而削弱种群分化。此前有研究提出，较强的扩散能力在异质性生境中或可促进种群分化，而在连续生境中则会抑制分化，但该假说尚未获得实证支持。本研究针对同时分布于异质性与连续生境中的一个扩散性燕类支系，比较了其种群分化模式。太平洋燕（Pacific Swallow, *Hirundo tahitica*）在东南亚及太平洋诸岛呈岛状分布，其姊妹种欢迎燕（Welcome Swallow, *Hirundo neoxena*）则在澳大利亚呈大陆分布。我们利用全基因组数据证实，岛状种群间存在显著的遗传结构与有限的基因渐渗，而大陆种群间则无此现象。种群动力学模型显示…… # 数据来源：《进化上易变的扩散行为与间断生境促进岛栖与陆栖燕类的种群分化》（Evolutionarily labile dispersal behavior and discontinuous habitats enhance population differentiation in island vs. continentally distributed swallows） DOI：https://doi.org/10.5061/dryad.18931zd3m ## 数据与文件结构说明 本次分析包含所有用于研究的样本的VCF（Variant Call Format）格式文件，该文件经过严格筛选，过滤标准为：测序深度最小值5、最大值50、reads质量值不低于30、次要等位基因频率≥5%、缺失数据占比低于15%，文件包含外类群样本。样本元数据可参见论文的补充表S1。 `water_gaps.csv`文件包含用于距离隔离分析的地理距离与水域阻隔分类数据： * 第一列代表种群间的直线最短距离（单位：千米）； * 第二列代表两个种群中心之间的直线距离（单位：千米）；该指标仅适用于欢迎燕，其扩散样本覆盖了不同区域……