Evolutionary Stress Ecology and Ecotoxicology, University of Leuven, Charles Debériotstraat 32, B-3000 Leuven, Belgium.
Freshwater Ecology, Evolution and Biodiversity Conservation, University of Leuven, Charles Debériotstraat 32, B-3000 Leuven, Belgium; Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany; Institute of Biology, Freie Universitat Berlin, Berlin, Germany.
Sci Total Environ. 2024 Sep 20;944:173070. doi: 10.1016/j.scitotenv.2024.173070. Epub 2024 May 9.
Despite the increasing evidence for rapid thermal evolution in natural populations, evolutionary rescue under global warming may be constrained by the presence of other stressors. Highly relevant in our polluted planet, is the largely ignored evolutionary trade-off between heat tolerance and tolerance to pollutants. By using two subpopulations (separated 40 years in time) from a resurrected natural population of the water flea Daphnia magna that experienced a threefold increase in heat wave frequency during this period, we tested whether rapid evolution of heat tolerance resulted in reduced tolerance to the widespread metal zinc and whether this would affect heat tolerance upon exposure to the pollutant. Our results revealed rapid evolution of increased heat tolerance in the recent subpopulation. Notably, the sensitivity to the metal tended to be stronger (reduction in net energy budget) or was only present (reductions in heat tolerance and in sugar content) in the recent subpopulation. As a result, the rapidly evolved higher heat tolerance of the recent subpopulation was fully offset when exposed to zinc. Our results highlight that the many reports of evolutionary rescue to global change stressors may give a too optimistic view as our warming planet is polluted by metals and other pollutants.
尽管越来越多的证据表明自然种群的快速热演化，但在全球变暖下的进化拯救可能会受到其他胁迫因素的限制。在我们这个被污染的星球上，一个很大程度上被忽视的进化权衡问题是耐热性和耐污染物之间的权衡。我们使用了两个亚种群（在这段时间内分开了 40 年），它们来自复活的水蚤（Daphnia magna）自然种群，在这段时间内，热浪的频率增加了两倍，我们测试了耐热性的快速进化是否会导致对广泛存在的金属锌的耐受性降低，以及这是否会影响暴露于污染物时的耐热性。我们的结果表明，近期亚种群的耐热性快速进化。值得注意的是，金属的敏感性往往更强（净能量预算减少），或者只在近期亚种群中存在（耐热性和糖含量降低）。因此，当近期亚种群暴露于锌时，其快速进化而来的更高耐热性完全被抵消了。我们的研究结果表明，许多关于对全球变化胁迫因素进行进化拯救的报告可能过于乐观，因为我们这个变暖的星球正受到金属和其他污染物的污染。
