Data from: Genetic patterns across an invasion's history: a test of change versus stasis for the Eurasian round goby in North America

Biological invasions comprise accidental evolutionary experiments, whose genetic compositions underlie relative success, spread, and persistence in new habitats. However, little is known about whether, or how, their population genetic patterns change temporally and/or spatially across the invasion's history. Theory predicts that most would undergo founder effect, exhibit low genetic divergence across the new range, and gain variation over time via new arriving propagules. To test these predictions, we analyze population genetic diversity and divergence patterns of the Eurasian round goby Neogobius melanostomus across the two decades of its North American invasion in the Laurentian Great Lakes, comparing results from 13 nuclear DNA microsatellite loci and mitochondrial DNA cytochrome b sequences. We test whether “genetic stasis”, “genetic replacement”, and/or “genetic supplement” scenarios have occurred at the invasion's core and expansion sites, in comparison to its primary native source population in the Dnieper River, Black Sea. Results reveal pronounced genetic divergence across the exotic range, with population areas remaining genetically distinct and statistically consistent across two decades, supporting “genetic stasis” and “founder takes most”. The original genotypes continue to predominate, whose high population growth likely outpaced the relative success of later arrivals. The original invasion core has stayed the most similar to the native source. Secondary expansion sites indicate slight allelic composition convergence towards the core population over time, attributable to some early “genetic supplementation”. The geographic and temporal coverage of this investigation offers a rare opportunity to discern population dynamics over time and space in context of invasion genetic theory versus reality.

生物入侵属于偶然发生的进化实验，其遗传组成决定了种群在新生境中实现相对成功、扩散与存续的能力。然而，学界对入侵全程中种群遗传格局是否会随时间、空间维度发生变化，以及具体的变化机制仍所知有限。现有理论预测，多数入侵种群会经历奠基者效应（founder effect），在新生分布区内呈现较低的遗传分化，并随时间通过新传入的繁殖体获得遗传变异。为验证上述理论预测，本研究针对欧亚圆虾虎鱼（Neogobius melanostomus）在北美劳伦琴五大湖（Laurentian Great Lakes）二十年的入侵过程，分析其种群遗传多样性与分化模式，采用13个核DNA微卫星位点（nuclear DNA microsatellite loci）与线粒体DNA细胞色素b（mitochondrial DNA cytochrome b）序列的数据开展分析，并以其原生分布区的主要来源种群——黑海（Black Sea）第聂伯河（Dnieper River）种群作为对照，检验入侵核心区与扩张区域是否发生了“遗传稳态”“遗传替换”或“遗传补充”情形。研究结果显示，外来入侵分布区呈现显著的遗传分化，各采样区域的遗传特征在二十年间始终保持显著差异且统计稳定，支持“遗传稳态”与“奠基者占优”假说；原始基因型仍占据主导地位，其快速的种群增长或许远超后续迁入个体的相对生存优势。最初形成的入侵核心区与原生来源种群的遗传相似度最高；次级扩张区域的等位基因组成随时间推移向核心种群出现轻微趋同，这可归因于早期发生的少量“遗传补充”事件。本研究的地理与时间覆盖范围，为在入侵遗传理论与实际观测的对照中解析种群动态提供了罕见的契机。