Range expansions are a potential outcome of changes in habitat suitability, which commonly result as a consequence of climate change. Hypotheses on such changes in the geographic distribution of a certain species can be evaluated using population genetic structure and demography. In this study we explore the population genetic structure, genetic variability, demographic history of, and habitat suitability for Amblyomma americanum , a North American tick species that is a known vector of several pathogenic microorganisms. We used a double digestion restriction site‐associated DNA sequencing technique (dd‐RAD seq) and discovered 8,181 independent single nucleotide polymorphisms (SNPs) in 189 ticks from across the geographic range of the species. Genetic diversity was low, particularly when considering the broad geographic range of this species. The edge populations were less diverse than populations belonging to the historic range, possibly indicative of a range expansion, but this hypothesis was not statistically supported by a test based on genetic data. Nonetheless, moderate levels of population structure and substructure were detected between geographic regions. For New England, demographic and species distribution models support a scenario where A. americanum was present in more northern locations in the past, underwent a bottleneck, and subsequently recovered. These results are consistent with a hypothesis that this species is re‐establishing in this area, rather than one focused on range expansion from the south. This hypothesis is consistent with old records describing the presence of A. americanum in the northeastern US in the early colonial period.

中文翻译：

---

孤星tick的种群遗传结构和人口历史（美洲盲mb）：支持旧记录的新证据。

范围扩大是栖息地适应性变化的潜在结果，通常是气候变化的结果。可以使用种群遗传结构和人口统计学来评估某些物种地理分布的这种假设。在这项研究中，我们探讨了美洲盲A的种群遗传结构，遗传变异，人口史和栖息地适宜性。是一种北美tick种，是几种病原微生物的已知载体。我们使用了双酶切限制性酶切位点相关的DNA测序技术（dd-RAD seq），在该物种的地理范围内的189个tick中发现了8,181个独立的单核苷酸多态性（SNP）。遗传多样性较低，尤其是考虑到该物种的广泛地理范围时。边缘种群的多样性不及属于历史范围的种群，可能表明范围扩大，但基于遗传数据的检验未从统计学上支持这一假设。但是，在地理区域之间检测到中等水平的人口结构和亚结构。对于新英格兰，人口和物种分布模型支持以下情况：过去，美洲念珠菌曾出现在更北部的地方，经历了瓶颈，随后得以恢复。这些结果与一种假设有关，即该物种正在该地区重新建立，而不是侧重于从南部扩展范围的假设。该假设与描述殖民地早期美国东北部存在美洲曲霉的旧记录一致。