Department of Environmental Sciences, Zoology, University of Basel, Vesalgasse 1, 4051 Basel, Switzerland.
Proc Biol Sci. 2019 Jul 24;286(1907):20190929. doi: 10.1098/rspb.2019.0929.
Species with wide geographical distributions are often adapted locally to the prevailing temperatures. To understand how they respond to ongoing climatic change, we must appreciate the interplay between temperature, seasonality and the organism's life cycle. The temperature experienced by many organisms results from an often-overlooked combination of climate and phenology. Summer-active (high latitude) populations are expected to adapt to local summer temperatures, but this is not expected for populations that outlive the summer in their dormant stage (low latitude, precipitation-limited). We recorded reproduction and survival in genotypes from 123 Holarctic populations of Daphnia magna during a multi-generation thermal ramp experiment. Genotypes from summer-active populations showed a positive relationship between heat tolerance and local summer temperature, whereas winter-active populations did not. These findings are consistent with the hypothesis that D. magna adapts to the local temperatures the animals experience during their planktonic phase. We conclude that predicting local temperature adaptation, in particular in the light of climate change, needs to consider the phenology of geographically wide-ranging species.
分布广泛的物种通常会适应当地流行的温度。为了了解它们如何应对正在发生的气候变化，我们必须理解温度、季节性和生物生命周期之间的相互作用。许多生物所经历的温度是由气候和物候之间经常被忽视的组合所决定的。夏季活跃（高纬度）的种群预计会适应当地的夏季温度，但对于在休眠阶段（低纬度、降水受限）度过夏季的种群则不会。我们在一项多代热斜坡实验中记录了来自 123 个北极圈 Daphnia magna 种群的基因型的繁殖和存活情况。来自夏季活跃种群的基因型显示出耐热性和当地夏季温度之间的正相关关系，而冬季活跃种群则没有。这些发现与 Daphnia magna 适应其浮游阶段动物所经历的当地温度的假设是一致的。我们的结论是，预测局部温度适应性，特别是在气候变化的背景下，需要考虑地理分布广泛的物种的物候。
