School of Biological Sciences, The University of Western Australia, Crawley, Western Australia, 6009, Australia.
Centre for Evolutionary Biology, The University of Western Australia, Crawley, Western Australia, 6009, Australia.
Evolution. 2020 Jun;74(6):1186-1199. doi: 10.1111/evo.13973. Epub 2020 May 5.
Intraspecific variation in the ability of individuals to tolerate environmental perturbations is often neglected when considering the impacts of climate change. Yet this information is potentially crucial for mitigating deleterious effects of climate change on threatened species. Here we assessed patterns of intraspecific variation in desiccation tolerance in the frog Pseudophryne guentheri, a terrestrial-breeding species experiencing a drying climate. Adult frogs were collected from six populations across a rainfall gradient and their dehydration and rehydration rates were assessed. We also compared desiccation tolerance of embryos and hatchlings originating from within-population parental crosses from four of the populations. Embryos were reared on soil at three soil-water potentials and their desiccation tolerance was assessed across a range of traits. We found significant and strong patterns of intraspecific variation in almost all traits, both in adults and first-generation offspring. Adult frogs exhibited clinal variation in their water balance responses, with populations from drier sites both dehydrating and rehydrating more slowly compared to frogs from more mesic sites. Similarly, desiccation tolerance of first-generation offspring was significantly greater in populations from xeric sites. Our findings suggest that populations within this species will respond differently to the regional reduction in rainfall predicted by climate change models.
在考虑气候变化的影响时，通常会忽略个体耐受环境干扰的能力的种内变异。然而，对于减轻气候变化对受威胁物种的有害影响，这些信息可能是至关重要的。在这里，我们评估了在经历干燥气候的陆生繁殖物种 Pseudophryne guentheri 中，脱水耐受性的种内变异模式。从六个降水梯度的种群中收集成年青蛙，并评估它们的脱水和复水速度。我们还比较了来自四个种群的种群内父母杂交的胚胎和幼体的脱水耐受性。将胚胎在三种土壤水分势下在土壤上饲养，并评估它们在一系列特征上的脱水耐受性。我们发现，在几乎所有特征中，无论是在成年个体还是第一代后代中，都存在显著且强烈的种内变异模式。成年青蛙的水分平衡反应表现出明显的梯度变化，与来自较湿润地区的青蛙相比，来自较干燥地区的青蛙脱水和复水的速度都较慢。同样，来自干旱地区的第一代后代的脱水耐受性显著更高。我们的研究结果表明，该物种的种群将对气候变化模型预测的区域降雨量减少做出不同的反应。
