Environment and phenology shape local adaptation in thermal performance

Populations within species often exhibit variation in traits that reflect local adaptation and further shape existing adaptive potential for species to respond to climate change. However, our mechanistic understanding of how the environment shapes trait variation remains poor. Here, we used common garden experiments to quantify thermal performance in eight populations of the marine snail Urosalpinx cinerea across thermal gradients on the Atlantic and the Pacific coasts of North America. We then evaluated the relationship between thermal performance and environmental metrics derived from time-series data. Our results reveal a novel pattern of “mixed” trait performance adaptation, where thermal optima was positively correlated with spawning temperature (cogradient variation), while maximum trait performance was negatively correlated with season length (countergradient variation). This counterintuitive pattern likely arises because of phenological shifts in the spawning season, whereby “co...

物种内的种群往往存在反映局部适应的性状变异，这类变异还会进一步塑造物种应对气候变化的既有适应潜力。然而，学界对环境如何塑造性状变异的机制性认知仍较为匮乏。本研究借助同质园实验（common garden experiments），对北美大西洋与太平洋沿岸热梯度环境下的8个海洋螺类Urosalpinx cinerea种群的热性能进行了量化。随后，我们评估了热性能与源自时间序列数据的环境指标之间的关联。研究结果揭示了一种全新的"混合"性状适应模式：热最适值与产卵温度呈正相关（协同梯度变异，cogradient variation），而最大性状性能与季节长度呈负相关（反梯度变异，countergradient variation）。这种反直觉的模式大概率源于产卵季的物候转变，即"协同……"