Population genetics and invasion history of the European Starling across Aotearoa, New Zealand: Batch 2 samples

The samples uploaded in this project are those sequenced in the second round of DArT-seq in 2023. The reads as provided by Diversity Arrays Technology come with sample barcodes already removed and with some pre-trimming.The expansion of human settlements over the past few centuries is responsible for an unprecedented number of invasive species introductions globally. An important component of biological invasion management is understanding how introduction history and post-introduction processes have jointly shaped present-day distributions and patterns of population structure, diversity, and adaptation. One example of a successful invader is the European starling (Sturnus vulgaris), which was intentionally introduced to numerous countries in the 19th century, including Aotearoa New Zealand, where it has become firmly established. We used reduced-representation sequencing to characterise the genetic population structure of the European starling in New Zealand, and compare the population structure to that present in sampling locations in the native range and invasive Australian range. We found that population structure and genetic diversity patterns suggested restricted gene flow from the majority of New Zealand to the northmost sampling location (Auckland). We also profiled genetic bottlenecks and shared outlier genomic regions, which supported historical accounts of translocations between both Australian subpopulations and New Zealand, and provided evidence of which translocation events were more likely to have been successful. Using these results as well as historic demographic patterns, we demonstrate how genomic analysis complements even well-documented invasion histories to better understand invasion processes, with direct implication for understanding contemporary gene flow and informing invasion management.

本项目上传的样本均为2023年第二轮DArT-seq测序所得样本。由Diversity Arrays Technology提供的测序读段（reads）已去除样本条形码并完成了部分预修剪步骤。
近几个世纪以来，人类定居点的扩张在全球范围内引发了史无前例的外来物种引入事件。生物入侵管理的核心一环，是厘清引入历史与引入后过程如何共同塑造了物种种群当前的分布格局、种群结构、遗传多样性与适应性模式。
成功入侵物种的典型案例之一为欧洲椋鸟（Sturnus vulgaris）：该物种于19世纪被有意引入多个国家，包括奥特亚罗瓦（Aotearoa，新西兰），目前已在当地稳固定殖。
本研究采用简化基因组测序（reduced-representation sequencing）技术，对新西兰境内欧洲椋鸟的遗传种群结构进行解析，并将其与该物种原生分布区以及入侵性澳大利亚分布区的采样点种群结构进行对比。
研究结果显示，种群结构与遗传多样性模式表明，新西兰绝大多数区域与最北部采样点奥克兰（Auckland）之间存在受限的基因交流。
本研究同时对遗传瓶颈（genetic bottlenecks）与共享的基因组离群区域（outlier genomic regions）进行了分析，结果佐证了澳大利亚两个亚种群与新西兰之间存在种群转移的历史记载，并为哪些转移事件更易获得成功提供了遗传学证据。
结合上述研究结果与历史种群动态模式，本研究阐明了基因组分析如何能够对已有详实记录的入侵历史进行补充，从而更深入地解析入侵过程，这对于理解当代基因交流以及指导入侵生物管理均具有直接的应用价值。