Data from: Does increased heat resistance result in higher susceptibility to predation? A test using (Drosophila melanogaster) selection and hardening

Heat resistance of ectotherms can be increased both by plasticity and evolution, but these effects may have trade-offs resulting from biotic interactions. Here we test for predation costs in <i>Drosophila melanogaster</i> populations with altered heat resistance produced by adult hardening and directional selection for increased heat resistance. In addition, we also tested for genetic trade-offs by testing heat resistance in lines that have evolved under increased predation risk. We show that while 35/37°C hardening increases heat resistance as expected, it does not increase predation risk from jumping spiders or mantids; in fact there was an indication that survival may have increased under predation following a triple 37°C compared to a single 35°C hardening treatment. Flies that survived a 39°C selection cycle showed lower survival under predation, suggesting a predation cost of exposure to a more severe heat stress. There was however no correlated response to selection because survival did not differ between control and selected lines after selection was relaxed for one or two generations. In addition, lines selected for increased predation risk did not differ in heat resistance. Our findings suggest independent evolutionary responses to predation and heat as measured in laboratory assays, and no costs of heat hardening on susceptibility to predation.变温动物（ectotherms）的耐热性可通过表型可塑性与演化两条途径提升，但这类效应可能因生物间相互作用产生适应性权衡。本研究针对通过成虫热硬化与耐热性定向选择获得耐热性改变的黑腹果蝇（Drosophila melanogaster）种群，检验其捕食代价。此外，本研究还通过对在捕食压力升高的环境下演化得到的果蝇品系开展耐热性检测，检验遗传层面的适应性权衡。 研究结果显示，尽管35℃/37℃热硬化如预期般提升了果蝇的耐热性，但并未增加其面临跳蛛或螳螂的捕食风险；事实上，相较于单次35℃热硬化处理，经三次37℃热硬化处理的果蝇在捕食压力下的存活率反而有所提升。经39℃筛选循环存活下来的果蝇在捕食压力下的存活率更低，这表明暴露于更强热胁迫会带来捕食代价。但并未观察到选择的相关响应：在选择放松1至2代后，对照组与选择组品系的存活率并无显著差异。此外，经捕食压力升高筛选的品系，其耐热性并未出现显著变化。本研究结果表明，在实验室检测条件下，果蝇对捕食压力与热胁迫的演化响应相互独立，且成虫热硬化并未增加果蝇的捕食易感性代价。