Urban landscape genetics: canopy cover predicts gene flow between white-footed mouse (Peromyscus leucopus) populations in New York City

In this study, I examine the influence of urban canopy cover on gene flow between 15 white-footed mouse (Peromyscus leucopus) populations in New York City. Nm calculated from F_ST and recent migration estimated in BayesAss+, but not historic migration estimated in Migrate-n, exhibited significant isolation-by-distance (IBD). Gene flow was also associated with “effective distances” between populations that were calculated based on percent canopy cover using two different approaches: 1) isolation-by-effective-distance (IED) that calculates the single best pathway to minimize passage through high-resistance (i.e. low canopy cover) areas, and 2) isolation-by-resistance (IBR), an implementation of circuit theory that identifies all low-resistance paths through the landscape. IBR, but not IED, models were still significantly associated with all three measures of gene flow after factoring out the influence of IBD using partial Mantel tests. In cases where both IBR and IED explained gene flow i...本研究探讨了城市冠层覆盖（urban canopy cover）对纽约市15个白足鼠（Peromyscus leucopus）种群间基因流（gene flow）的影响。基于F_ST计算得到的Nm值，以及在BayesAss+中估算的近期迁移率（而非Migrate-n所估算的历史迁移率），均表现出显著的距离隔离（isolation-by-distance，IBD）效应。种群间的基因流还与基于冠层覆盖百分比、通过两种不同方法计算得到的有效距离（effective distances）相关：1）有效距离隔离（isolation-by-effective-distance，IED），即通过计算单条最优路径以最小化穿过高抗性（即低冠层覆盖）区域的通行；2）抗性隔离（isolation-by-resistance，IBR），该方法是电路理论（circuit theory）的一种实现形式，可识别景观中所有低抗性通路。通过偏曼特尔检验（partial Mantel tests）排除距离隔离（IBD）的影响后，抗性隔离（IBR）模型（而非有效距离隔离（IED）模型）仍与三项基因流指标均呈显著相关。在抗性隔离（IBR）与有效距离隔离（IED）均能解释基因流的情形中……