Data from: Neutral biogeography and the evolution of climatic niches

Recent debate on whether climatic niches are conserved through time has focused on how phylogenetic niche conservatism can be measured by deviations from a Brownian motion model of evolutionary change. However, there has been no evaluation of this methodological approach. In particular, the fact that climatic niches are usually obtained from distribution data and are thus heavily influenced by biogeographic factors has largely been overlooked. Our main objective here was to test whether patterns of climatic niche evolution that are frequently observed might arise from neutral dynamics rather than adaptive scenarios. We develop a model inspired by Neutral Biodiversity Theory, where individuals disperse, compete, and undergo speciation independently of climate. We then sample the climatic niches of species according to their geographic position and show that even when species evolved independently of climate, their niches can nonetheless exhibit evolutionary patterns strongly differing from Brownian motion. Indeed, climatic niche evolution is better captured by a model of punctuated evolution with constraints due to landscape boundaries, two features that are traditionally interpreted as evidence for selective processes acting on the niche. We therefore suggest that deviation from Brownian motion alone should not be used as evidence for phylogenetic niche conservatism, but that information on phenotypic traits directly linked to physiology is required to demonstrate that climatic niches have been conserved through time.

近年来围绕气候生态位是否随时间保持保守的学术争论，核心聚焦于如何通过偏离演化变化的布朗运动（Brownian motion）模型，来量化系统发育生态位保守性（phylogenetic niche conservatism）。然而，学界尚未对这一方法论路径开展系统性评估。尤为关键的是，气候生态位通常源自物种分布数据，因而极易受到生物地理因素的强烈影响，这一关键前提在既往研究中基本被忽视。本研究的核心目标在于检验：当前频繁观测到的气候生态位演化模式，是否可能由中性动态过程而非适应性演化场景所催生。我们基于中性生物多样性理论（Neutral Biodiversity Theory）构建演化模型，该模型中个体的扩散、种间竞争与物种形成均与气候因素无关。随后，我们依据物种的地理分布位置对其气候生态位进行采样分析，结果显示，即便物种演化进程不受气候调控，其生态位仍可呈现出与布朗运动模型显著偏离的演化模式。事实上，带有景观边界约束的间断演化（punctuated evolution）模型，更能准确刻画气候生态位的演化过程——而这两大特征（间断演化与景观约束）在传统研究中常被解读为生态位受选择作用驱动的直接证据。因此，我们认为，仅以偏离布朗运动模型这一单一指标，不足以作为系统发育生态位保守性的佐证；若要严谨证明气候生态位随时间保持保守，还需获取与物种生理机能直接相关的表型性状（phenotypic traits）相关数据。