Population divergence and gene flow are key processes in evolution and ecology. Model‐based analysis of genome‐wide data sets allows discrimination between alternative scenarios for these processes even in nonmodel taxa. We used two complementary approaches (one based on the blockwise site frequency spectrum [bSFS], the second on the pairwise sequentially Markovian coalescent [PSMC]) to infer the divergence history of a fig wasp, Pleistodontes nigriventris. Pleistodontes nigriventris and its fig tree mutualist Ficus watkinsiana are restricted to rain forest patches along the eastern coast of Australia and are separated into The Northern population is to the north of the Southern populations by two dry forest corridors (the Burdekin and St. Lawrence Gaps). We generated whole genome sequence data for two haploid males per population and used the bSFS approach to infer the timing of divergence between northern and southern populations of P. nigriventris, and to discriminate between alternative isolation with migration (IM) and instantaneous admixture (ADM) models of postdivergence gene flow. Pleistodontes nigriventris has low genetic diversity (π = 0.0008), to our knowledge one of the lowest estimates reported for a sexually reproducing arthropod. We find strongest support for an ADM model in which the two populations diverged ca. 196 kya in the late Pleistocene, with almost 25% of northern lineages introduced from the south during an admixture event ca. 57 kya. This divergence history is highly concordant with individual population demographies inferred from each pair of haploid males using PSMC. Our analysis illustrates the inferences possible with genome‐level data for small population samples of tiny, nonmodel organisms and adds to a growing body of knowledge on the population structure of Australian rain forest taxa.

中文翻译：

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低覆盖率的基因组数据解决了澳大利亚雨林无花果黄蜂的种群差异和基因流历史。

人口差异和基因流动是进化和生态学中的关键过程。基于模型的全基因组数据集分析可以区分这些过程的替代方案，即使在非模型分类单元中也是如此。我们使用了两种互补的方法（一种基于块状站点频谱[bSFS]，第二种基于成对顺序马尔可夫聚结[PSMC]）来推断无花果黄蜂Pleistodontes nigriventris的发散历史。杏鲍菇及其无花果树互惠生榕属watkinsiana仅限于澳大利亚东部沿海的雨林片区，并通过两个干燥的森林走廊（伯德金和圣劳伦斯峡）分为北部居民区和南部居民区的北部。我们产生了全基因组序列数据为每人口2名单倍体男性和使用的BSFS接近来推断的北部和南部群体之间差异的定时P. nigriventris，并用迁移（IM）替代隔离和瞬时混合（ADM）之间进行区分后散基因流模型。黑粉菌据我们所知，其遗传多样性低（π= 0.0008），是有性节肢动物报告的最低估计值之一。我们找到一个ADM模型，其中两个群体分歧强有力的支持CA。在晚更新世后期为196 kya，大约有25％的北方谱系在混合事件中从南方引入。57凯。这种差异的历史与使用PSMC从每对单倍体雄性中推断出的个体人口统计学高度一致。我们的分析说明了使用基因组水平数据对微小的非模型生物的少量种群样本进行推断的可能性，并增加了有关澳大利亚雨林分类群种群结构的知识。