The effect of habitat fragmentation on the genetic structure of a top predator: loss of diversity and high differentiation among remnant populations of Atlantic Forest jaguars (Panthera onca)

Habitat fragmentation may disrupt original patterns of gene flow and lead to drift-induced differentiation among local population units. Top predators such as the jaguar may be particularly susceptible to this effect, given their low population densities, leading to small effective sizes in local fragments. On the other hand, the jaguar's high dispersal capabilities and relatively long generation time might counteract this process, slowing the effect of drift on local populations over the time frame of decades or centuries. In this study, we have addressed this issue by investigating the genetic structure of jaguars in a recently fragmented Atlantic Forest region, aiming to test whether loss of diversity and differentiation among local populations are detectable, and whether they can be attributed to the recent effect of drift. We used 13 microsatellite loci to characterize the genetic diversity present in four remnant populations, and observed marked differentiation among them, with ev...生境破碎化（habitat fragmentation）可能破坏原有的基因流（gene flow）模式，进而导致局部种群单元间出现由遗传漂变（genetic drift）诱导的分化。由于种群密度较低，局部破碎生境中的有效种群规模偏小，因此包括美洲豹（jaguar）在内的顶级捕食者对这一效应尤为易感。另一方面，美洲豹较强的扩散能力与相对较长的世代周期，或可抵消这一过程，在数十年乃至数百年的时间尺度上减缓遗传漂变对局部种群的影响。本研究针对近期发生破碎化的大西洋森林（Atlantic Forest）区域内的美洲豹种群遗传结构展开探究，旨在检测局部种群间是否存在可观测的遗传多样性丧失与分化现象，并判断这些现象是否可归因于近期的遗传漂变作用。我们利用13个微卫星位点（microsatellite loci）对4个残存种群的遗传多样性进行了分型表征，并观测到种群间存在显著分化，[原文至此截断]