Halliday William D, Blouin-Demers Gabriel
Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, Canada K1N 6N5.
J Therm Biol. 2017 Oct;69:206-212. doi: 10.1016/j.jtherbio.2017.07.017. Epub 2017 Jul 29.
Whole-organism performance of ectotherms depends on body temperature, which is tightly linked to environmental temperatures. Individuals attempting to optimize fitness must thus select appropriate temperatures. The thermal coadaptation hypothesis posits that T for traits closely linked to fitness should match temperatures selected by a species (T) and should coevolve with T. T may mismatch T if the thermal reaction norm for fitness is asymmetric. In this study, we examined six traits related to fitness in red and in confused flour beetles (Tribolium castaneum and T. confusum, respectively), including longevity, lifetime reproductive success, reproductive rate, and development time at four temperatures between 23 and 32°C. For reproductive traits, T matched T whereas for longevity T was lower than T. Tribolium species have a strongly r-selected life history strategy, therefore reproductive traits are likely more tightly linked to fitness than longevity due to high predation rates at early life stages. We therefore provide support for the thermal coadaptation hypothesis for reproductive traits that are tightly linked to fitness. Our results highlight the importance of knowing the relationships of traits to fitness when studying thermal physiology.
变温动物的整体表现取决于体温，而体温与环境温度紧密相关。因此，试图优化适应性的个体必须选择适宜的温度。热共适应假说认为，与适应性密切相关的性状的最适温度（T）应与物种选择的温度（T）相匹配，并且应与T共同进化。如果适应性的热反应规范不对称，T可能与T不匹配。在本研究中，我们分别研究了赤拟谷盗和杂拟谷盗（分别为Tribolium castaneum和T. confusum）与适应性相关的六个性状，包括在23至32°C之间的四个温度下的寿命、终生繁殖成功率、繁殖率和发育时间。对于繁殖性状，T与T相匹配，而对于寿命，T低于T。拟谷盗物种具有强烈的r选择生活史策略，因此由于早期生命阶段的高捕食率，繁殖性状可能比寿命更紧密地与适应性相关。因此，我们为与适应性紧密相关的繁殖性状的热共适应假说提供了支持。我们的结果强调了在研究热生理学时了解性状与适应性关系的重要性。
