Anstett Daniel N, Branch Haley A, Angert Amy L
Biodiversity Research Centre and Department of Botany University of British Columbia Vancouver British Columbia V6T 1Z4 Canada.
Department of Zoology University of British Columbia Vancouver British Columbia V6T 1Z4 Canada.
Evol Lett. 2021 Feb 23;5(2):130-142. doi: 10.1002/evl3.218. eCollection 2021 Apr.
Climate change is increasing drought intensity, threatening biodiversity. Rapid evolution of drought adaptations might be required for population persistence, particularly in rear-edge populations that may already be closer to physiological limits. Resurrection studies are a useful tool to assess adaptation to climate change, yet these studies rarely encompass the geographic range of a species. Here, we sampled 11 populations of scarlet monkeyflower (), collecting seeds across the plants' northern, central, and southern range to track trait evolution from the lowest to the greatest moisture anomaly over a 7-year period. We grew families generated from these populations across well-watered and terminal drought treatments in a greenhouse and quantified five traits associated with dehydration escape and avoidance. When considering pre-drought to peak-drought phenotypes, we find that later date of flowering evolved across the range of , suggesting a shift away from dehydration escape. Instead, traits consistent with dehydration avoidance evolved, with smaller and/or thicker leaves evolving in central and southern regions. The southern region also saw a loss of plasticity in these leaf traits by the peak of the drought, whereas flowering time remained plastic across all regions. This observed shift in traits from escape to avoidance occurred only in certain regions, revealing the importance of geographic context when examining adaptations to climate change.
气候变化正在加剧干旱强度，威胁生物多样性。种群的持续存在可能需要干旱适应性的快速进化，特别是在可能已经更接近生理极限的边缘种群中。复活研究是评估对气候变化适应性的有用工具，但这些研究很少涵盖一个物种的地理范围。在这里，我们对11个猩红色猴面花种群进行了采样，在该植物的北部、中部和南部分布范围内收集种子，以追踪7年期间从最低到最大水分异常情况下的性状进化。我们在温室中对这些种群产生的家系进行了充分浇水和极端干旱处理，并对与脱水逃避和避免相关的五个性状进行了量化。当考虑干旱前到干旱高峰期的表型时，我们发现在整个分布范围内开花日期变晚，这表明从脱水逃避策略发生了转变。相反，与脱水避免一致的性状进化了，中部和南部地区的叶子变得更小和/或更厚。到干旱高峰期，南部地区这些叶片性状的可塑性也有所丧失，而开花时间在所有地区仍保持可塑性。这种从逃避到避免的性状转变仅在某些地区出现，揭示了在研究对气候变化的适应性时地理背景的重要性。
