PDF(Pubmed)
Abstract：
The biogeographic history of the Chihuahuan Desert is complex, driven by numerous physiographic events and climatic changes. This dynamic history would have influenced the flora and fauna of the region including the desert pocket gopher, Geomys arenarius, a subterranean rodent endemic to the northern Chihuahuan Desert. G. arenarius is restricted to sandy soils and are considered to have a disjunct distribution. Two subspecies are recognized: G. a. arenarius and G. a. brevirostris. We used multilocus nuclear (amplified fragment length polymorphisms) and mitochondrial DNA (ND2) sequence data to uncover patterns of genetic diversity within and among populations of G. arenarius. We evaluated correspondence of genetic patterns to traditionally accepted subspecies boundaries, mapped the distribution of potentially suitable soils to identify barriers or corridors to dispersal and to guide future survey efforts, provided evidence that could be used to recognize distinct population segments, and quantified genetic diversity within populations. Both datasets were largely concordant and demonstrated hierarchical patterns of genetic divergence. The greatest divergence was consistent with the two recognized subspecies. Mapping of potentially habitable soils revealed likely barriers to dispersal contributing to the allopatric pattern of geographic distribution and areas, which may be occupied by G. arenarius but not yet documented. Because G. arenarius is restricted to soils with high sand content, and these habitable soils are disjunct within the region occupied by this species, historical factors that impacted soil deposition and deflation likely contributed to the observed patterns of genetic divergence. Genetic diversity was higher within populations of the southern subspecies (G. a. arenarius) compared to G. a. brevirostris. This may be due to a greater availability of continuous suitable soils within the range of G. a. arenarius or higher density due to greater food availability (currently or historically)-both of which could allow for a higher effective population size.
摘要：
奇瓦瓦沙漠的生物地理历史十分复杂,受众多生理事件和气候变化的驱动。这种动态的历史将影响该地区的动植物，包括沙漠口袋地鼠，Geomysarenarius，奇瓦瓦沙漠北部特有的一种地下啮齿动物。沙地仅限于沙质土壤，被认为具有分离的分布。识别两个亚种:G.a.arenarius和G.a.brevirostris.我们使用多基因座核（扩增的片段长度多态性）和线粒体DNA（ND2）序列数据来揭示G.arenarius种群内部和种群之间的遗传多样性模式。我们评估了遗传模式与传统上接受的亚种边界的对应关系，绘制潜在合适土壤的分布图，以确定要分散的障碍或走廊，并指导未来的调查工作，提供了可用于识别不同人群的证据，和种群内量化的遗传多样性。这两个数据集在很大程度上是一致的，并证明了遗传差异的分层模式。最大的差异与两个公认的亚种一致。对潜在可居住土壤的绘图表明，可能存在分散障碍，这导致了地理分布和地区的异同格局。可能被G.arenarius占用，但尚未记录。因为沙马被限制在含沙量高的土壤中，这些可居住的土壤在该物种占据的区域内是分离的，影响土壤沉积和通货紧缩的历史因素可能导致了观察到的遗传差异模式。南方亚种种群内的遗传多样性较高（G.Procedures.arenarius）与G.a.brevirostris.这可能是由于在G.a.由于更多的食物供应（当前或历史上），竞技场或更高的密度-两者都可以实现更高的有效人口规模。
