Testing for local adaptation and evolutionary potential along altitudinal gradients in rainforest Drosophila: beyond laboratory estimates.
Testing for local adaptation and evolutionary potential along altitudinal gradients in rainforest Drosophila: beyond laboratory estimates.
复制标题
热带雨林果蝇沿海拔梯度的局部适应和进化潜力测试：超出实验室估计。
DOI：
10.1111/gcb.13553
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发表时间：
2017
影响因子：
11.6
通讯作者：
O'Brien EK
中科院分区：
文献类型：
--
作者：
O'Brien EK
预测物种将如何应对本世纪预测的快速气候变化是一项紧迫的任务。物种分布模型（SDM）利用环境变化与物种丰度之间的关系来预测未来环境变化对物种分布的影响。然而，在许多情况下，空间数据模型的两个共同假设可能会被违反：㈠环境与丰度或适合度的关系在整个物种范围内是恒定的，并且在未来将保持不变; ㈡非生物因素（如温度、湿度）决定物种的分布。我们测试这些假设相关领域丰富的热带雨林果蝇birchiito生态变化的梯度，包括其低海拔和高海拔的限制。然后，我们测试这种生态变化如何影响的健身35 D. birchiifamilies移植在591笼网站沿着两个海拔梯度，以确定是否遗传变异的健身反应，可以促进未来的适应环境变化。总的来说，在较冷的高海拔地区，野外丰度最高，而在较温暖的低海拔地区，野外丰度则下降。相比之下，笼子的适合度（生产力）朝着更温暖，海拔更低的地点增加，这表明生物相互作用（不存在于笼子中）在温暖的边缘驱动生态极限。此外，环境变化与多度之间的关系在不同梯度之间存在显著差异，表明不同物种的生态位存在差异。然而，没有证据表明梯度内的局部适应，尽管在实验室条件下饲养的家庭高海拔种群的生产力高于低海拔种群。家庭对沿着梯度移植的反应也类似，没有提供有利于当地适应的适应性权衡的证据。这些发现强调了（i）在生态相关条件下测量关键性状的遗传变异的重要性，以及（ii）在预测物种对环境变化的反应时考虑生物相互作用的影响。
Predicting how species will respond to the rapid climatic changes predicted this century is an urgent task. Species distribution models (SDMs) use the current relationship between environmental variation and species’ abundances to predict the effect of future environmental change on their distributions. However, two common assumptions of SDMs are likely to be violated in many cases: (i) that the relationship of environment with abundance or fitness is constant throughout a species’ range and will remain so in future and (ii) that abiotic factors (e.g. temperature, humidity) determine species’ distributions. We test these assumptions by relating field abundance of the rainforest fruit flyDrosophila birchiito ecological change across gradients that include its low and high altitudinal limits. We then test how such ecological variation affects the fitness of 35D. birchiifamilies transplanted in 591 cages to sites along two altitudinal gradients, to determine whether genetic variation in fitness responses could facilitate future adaptation to environmental change. Overall, field abundance was highest at cooler, high‐altitude sites, and declined towards warmer, low‐altitude sites. By contrast, cage fitness (productivity)increasedtowards warmer, lower‐altitude sites, suggesting that biotic interactions (absent from cages) drive ecological limits at warmer margins. In addition, the relationship between environmental variation and abundance varied significantly among gradients, indicating divergence in ecological niche across the species’ range. However, there was no evidence for local adaptation within gradients, despite greater productivity of high‐altitude than low‐altitude populations when families were reared under laboratory conditions. Families also responded similarly to transplantation along gradients, providing no evidence for fitness trade‐offs that would favour local adaptation. These findings highlight the importance of (i) measuring genetic variation in key traits under ecologically relevant conditions, and (ii) considering the effect of biotic interactions when predicting species’ responses to environmental change.