Data from: Demographic history influences spatial patterns of genetic diversity in recently expanded coyote (Canis latrans) populations

Human-mediated range expansions have increased in recent decades and represent unique opportunities to evaluate genetic outcomes of establishing peripheral populations across broad expansion fronts. Over the past century, coyotes (Canis latrans) have undergone a pervasive range expansion and now inhabit every state in the continental United States. Coyote expansion into eastern North America was facilitated by anthropogenic landscape changes and followed two broad expansion fronts. The northern expansion extended through the Great Lakes region and southern Canada, where hybridization with remnant wolf populations was common. The southern and more recent expansion front occurred approximately 40 years later and across territory where gray wolves have been historically absent and remnant red wolves were extirpated in the 1970s. We conducted a genetic survey at 10 microsatellite loci of 482 coyotes originating from 11 eastern U.S. states to address how divergent demographic histories influence geographic patterns of genetic diversity. We found that population structure corresponded to a north-south divide, which is consistent with the two known expansion routes. Additionally, we observed extremely high genetic diversity, which is atypical of recently expanded populations and is likely the result of multiple complex demographic processes, in addition to hybridization with other Canis species. Finally, we considered the transition of allele frequencies across geographic space and suggest the mid-Atlantic states of North Carolina and Virginia as an emerging contact zone between these two distinct coyote expansion fronts.

近数十年来，人类活动介导的物种分布范围扩张事件愈发频发，为解析跨大范围扩张前沿建立边缘种群的遗传效应提供了独特契机。过去一个世纪内，郊狼（Canis latrans）经历了广泛的分布范围扩张，如今已遍布美国本土的所有州份。郊狼向北美东部的扩张得益于人为景观改造，并沿两条主要扩张前沿推进：北部扩张路径贯穿五大湖地区与加拿大南部，该区域内郊狼与残存灰狼种群的杂交事件较为常见；南部扩张前沿的推进时间则晚了约40年，其途经区域历史上并无灰狼分布，且残存红狼已于20世纪70年代被彻底清除。我们针对采自美国东部11个州的482只郊狼，开展了基于10个微卫星位点（microsatellite loci）的遗传调查，旨在探究差异化的种群历史动态如何影响遗传多样性的地理分布格局。研究发现，种群结构呈现南北分化的特征，这与已知的两条扩张路径完全吻合。此外，我们观测到极高的遗传多样性水平——这与新近扩张种群的典型特征相悖，其成因很可能除了与其他犬科物种的杂交外，还涉及多种复杂的种群历史动态过程。最后，我们通过分析等位基因频率的地理空间过渡模式，提出北卡罗来纳州与弗吉尼亚州所在的大西洋中部区域，是这两条独立郊狼扩张前沿之间正在形成的遗传接触带。