School of the Environment, Yale University, New Haven, Connecticut, 06520.
Evolution. 2021 Nov;75(11):2930-2943. doi: 10.1111/evo.14350. Epub 2021 Sep 25.
Environmental change is predicted to accelerate into the future and will exert strong selection pressure on biota. Although many species may be fated to extinction, others may survive through their capacity to evolve rapidly at highly localized (i.e., microgeographic) scales. Yet, even as new examples have been discovered, the limits to such evolutionary responses have not often been evaluated. One of the first examples of microgeographic variation involved pond populations of wood frogs (Rana sylvatica). Although separated by just tens to hundreds of meters, these populations exhibited countergradient variation in intrinsic embryonic development rates when reared in a common garden. We repeated this experiment 17 years (approximately six to nine generations) later and found that microgeographic variation persists in contemporary populations. Furthermore, we found that contemporary embryos have evolved to develop 14-19% faster than those in 2001. Structural equation models indicate that the predominant cause for this response is likely due to changes in climate over the intervening 17 years. Despite potential for rapid and fine-scale evolution, demographic declines in populations experiencing the greatest changes in climate and habitat imply a limit to the species' ability to mitigate extreme environmental change.
环境变化预计将在未来加速，并对生物群施加强大的选择压力。尽管许多物种可能注定要灭绝，但其他物种可能通过在高度本地化（即微观地理）尺度上快速进化的能力而幸存下来。然而，即使新的例子已经被发现，这种进化反应的极限也没有经常被评估。微观地理变异的第一个例子涉及林蛙（Rana sylvatica）的池塘种群。尽管这些种群仅相隔数十到数百米，但当在一个共同的花园中饲养时，它们表现出内在胚胎发育率的反梯度变异。我们在 17 年后（大约六到九代）重复了这个实验，发现微观地理变异在当代种群中仍然存在。此外，我们发现当代胚胎的发育速度比 2001 年的胚胎快 14-19%。结构方程模型表明，这种反应的主要原因可能是由于 17 年来气候的变化。尽管存在快速和精细尺度进化的潜力，但在经历最大气候变化和生境变化的种群中，种群数量的下降意味着该物种缓解极端环境变化的能力有限。
