German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.
Leipzig University, Ritterstraße 26, 04109, Leipzig, Germany.
Nat Commun. 2021 Feb 19;12(1):1198. doi: 10.1038/s41467-021-21263-8.
Understanding how species' thermal limits have evolved across the tree of life is central to predicting species' responses to climate change. Here, using experimentally-derived estimates of thermal tolerance limits for over 2000 terrestrial and aquatic species, we show that most of the variation in thermal tolerance can be attributed to a combination of adaptation to current climatic extremes, and the existence of evolutionary 'attractors' that reflect either boundaries or optima in thermal tolerance limits. Our results also reveal deep-time climate legacies in ectotherms, whereby orders that originated in cold paleoclimates have presently lower cold tolerance limits than those with warm thermal ancestry. Conversely, heat tolerance appears unrelated to climate ancestry. Cold tolerance has evolved more quickly than heat tolerance in endotherms and ectotherms. If the past tempo of evolution for upper thermal limits continues, adaptive responses in thermal limits will have limited potential to rescue the large majority of species given the unprecedented rate of contemporary climate change.
了解物种的热极限是如何在生命之树上进化的，对于预测物种对气候变化的反应至关重要。在这里，我们使用超过 2000 种陆地和水生物种的热耐受极限的实验衍生估计值，表明热耐受的大多数变异可以归因于对当前气候极端情况的适应，以及进化“吸引子”的存在，这些吸引子反映了热耐受极限的边界或最佳值。我们的研究结果还揭示了变温动物的深层时间气候遗产，即起源于寒冷古气候的目比具有温暖热祖的目具有更低的耐寒性极限。相反，耐热性似乎与气候祖先无关。在恒温动物和变温动物中，耐寒性的进化速度比耐热性快。如果上热极限的过去进化速度继续下去，那么考虑到当代气候变化前所未有的速度，热极限的适应性反应将没有多大潜力拯救绝大多数物种。
