Isolation can affect genetic structure of populations near the edge of a species’ geographic range by reducing gene flow and allelic diversity, resulting in greater among-population differentiation. Spruce Grouse (Falcipennis canadensis), which are restricted to the boreal forest biome of North America, persist in small, disjunct lowland conifer patches at the southeastern extent of their range in the Adirondack Mountains of New York. This isolated peripheral population has declined since the early twentieth century and is considered highly vulnerable to extirpation. We examined haplotype diversity of mitochondrial control region sequences, comparing modern Spruce Grouse populations sampled from 2004 to 2013 in the Adirondacks and Algonquin Provincial Park, ca. 250 km to the northwest. Genetic diversity in the modern Adirondack population sample was very low compared to our smaller sample from Algonquin Park (three haplotypes vs seven). The modern Adirondack population shared no haplotypes with birds sampled from Algonquin, and these two populations are highly differentiated today (Fst = 0.632). We obtained shorter control region sequences from 18 museum specimens collected in the Adirondack from 1881 to 1986, in which we found six haplotypes, including five no longer found in the Adirondack Region. Some haplotypes that were once found in both regions have been lost from the Adirondacks as that population has declined demographically and shrunk geographically, indicating that the current differentiation is partly the result of these losses; when all 18 historical samples of Adirondack Spruce Grouse are included in the analysis, Fst between Adirondacks and Algonquin drops to 0.359. Haplotype diversity in Adirondack specimens collected prior to demographic decline (1881–1905, n = 10) was h = 0.778 compared to h = 0.245 in the modern Adirondack population, an over a three-fold decrease over period of ca. 130 years. These findings suggest that conservation measures that include supplementation of individuals from more diverse populations may restore genetic diversity in the Adirondack population to levels that existed a century ago.

隔离会减少基因流和等位基因多样性，从而影响物种地理范围边缘附近种群的遗传结构，从而导致更大的种群间分化。云杉松鸡（Falcipennis canadensis）仅限于北美的北方森林生物群落，但仍在纽约阿迪朗达克山脉范围东南部的小而分散的低地针叶林片上。自20世纪初以来，这种孤立的外围人口有所减少，被认为极易灭绝。我们检查了线粒体控制区序列的单倍型多样性，比较了2004年至2013年在阿地伦达山脉和阿冈昆省立公园（加利福尼亚州）采样的现代云杉松鸡种群。西北250公里。与我们的阿冈昆公园较小样本相比，现代阿迪朗达克种群样本中的遗传多样性非常低（三种单倍型对七种）。现代的阿迪朗达克（Adirondack）种群与从阿尔冈昆（Algonquin），并且这两个人口今天高度分化（Fst = 0.632）。我们从1881年至1986年在阿迪朗达克（Adirondack）收集的18个博物馆标本中获得了较短的控制区序列，在其中我们发现了6个单倍型，其中5个在阿迪朗达克地区不再存在。在这两个地区曾经发现的一些单倍型已经从阿地伦达山脉中消失了，因为该人口在人口统计学上有所下降，在地理上有所缩小，这表明当前的分化部分是这些损失的结果。当分析中包括全部18个阿迪朗达克云杉松鸡的历史样本时，F 在这两个地区曾经发现的一些单倍型已经从阿地伦达山脉中消失了，因为该人口在人口统计学上有所下降，在地理上有所缩小，这表明当前的分化部分是这些损失的结果。当分析中包括全部18个阿迪朗达克云杉松鸡的历史样本时，F 在这两个地区曾经发现的一些单倍型已经从阿地伦达山脉中消失了，因为该人口在人口统计学上有所下降，在地理上有所缩小，这表明当前的分化部分是这些损失的结果。当分析中包括全部18个阿迪朗达克云杉松鸡的历史样本时，F阿迪朗达克山脉和阿冈昆山脉之间的st下降至0.359。在人口下降之前（1881-1905年，n = 10）收集的阿迪朗达克标本的单倍型多样性为h  = 0.778  ，而现代阿迪朗达克人口的h = 0.245，在过去约三倍的时间内下降了。130年 这些发现表明，包括补充来自更多不同种群的个体的保护措施可以将阿迪朗达克种群的遗传多样性恢复到一个世纪前的水平。