Dissertation Research: Genetic and Demographic Responses of Wood Frogs to Induced Population Subdivision

我们建议研究人类诱导的种群细分对林蛙的遗传和人口统计学影响。林蛙是一种水生繁殖的陆栖两栖动物，生活在中原林地。我们的研究将考察美国康涅狄格州南部高度城市化地区25个林蛙亚群的遗传变异和分化模式，这些亚群在大小(10-1000个个体)、隔离时间(O、10、100和10000年)和栖息地连通性程度方面差异很大。景观间隔子种群的特征将与亚种群之间的遗传相似性估计相关联，以检查哪些地理特征是基因流动的障碍和路径。一种新的实验程序，包括在选定的景观配置中放置人工繁殖池，将被用来评估人类制造的屏障的“孔隙度”，以驱散小青蛙。(通过检查地图和航空照片)对上个世纪研究区域栖息地和种群碎片化的研究将有助于理解动物地理因素和历史人口统计学因素如何影响林蛙种群水平的系统发育。保护生物学家对这些信息特别感兴趣。他们越来越关注在人工碎片化的种群中长期维持遗传多样性。

We propose to investigate genetic and demographic effects of human- induced population subdivision on the wood frog (Rana sylvatica), an aquatic-breeding, terrestrial-dwelling amphibian of mesic woodlands. Our study will examine patterns of genetic variation within and divergence among 25 subpopulations of wood frogs in a heavily urbanized area of southern Connecticut, U.S.A., where subpopulations vary widely in size (10-1,000 individuals), length of isolation (O, 10, 100, and 10,000 years), and degree of habitat connectivity. Features of the landscape intervening subpopulations will be correlated with estimates of genetic similarity between subpopulations to examine which geographic features act as barriers versus paths to gene flow. A novel experimental procedure, involving placement of artificial breeding pools in selected landscape configurations, will be used to assess the "porosity" of human-created barriers to disperse froglets. An examination of how habitat and population fragmentation has proceeded in the study area during the last century (by inspection of maps and aerial photographs) will aid in understanding how both zoogeographic factors and historical demography shaped population-level phylogenies of wood frogs. Such information is of particular interest to conservation biologists. who are increasingly concerned with long-term maintenance of genetic diversity in artificially fragmented populations.