Kingsolver Joel G, Ragland Gregory J, Diamond Sarah E
Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
Evolution. 2009 Feb;63(2):537-41. doi: 10.1111/j.1558-5646.2008.00568.x. Epub 2008 Dec 19.
Adaptation to temporal variation in environmental conditions is widespread. Whether evolution in a constant environment alters adaptation to temporal variation is relatively unexplored. We examine how constant and diurnally fluctuating temperature conditions affect life-history traits in two populations of the tobacco hornworm, Manduca sexta: a field population that routinely experiences fluctuating temperatures; and a laboratory population (derived from this field population in the 1960s) maintained at a constant temperature for more than 250 generations. Our experiments demonstrate that diurnal fluctuations significantly alter body size and development time in both populations, and confirm that these populations differ in their responses to a mean temperature. However, we found no evidence for population divergence in responses to diurnal temperature fluctuations. We suggest that mean and extreme temperatures may act as more potent selective forces on thermal reaction norms than temperature variation per se.
对环境条件的时间变化的适应是广泛存在的。在恒定环境中的进化是否会改变对时间变化的适应，这一点相对较少被研究。我们研究了恒定温度和昼夜波动温度条件如何影响烟草天蛾（Manduca sexta）两个种群的生活史特征：一个是经常经历温度波动的野外种群；另一个是实验室种群（20世纪60年代源自该野外种群），在恒定温度下维持了超过250代。我们的实验表明，昼夜波动显著改变了两个种群的体型和发育时间，并证实这些种群对平均温度的反应存在差异。然而，我们没有发现种群在对昼夜温度波动的反应上存在差异的证据。我们认为，平均温度和极端温度可能比温度本身的变化对热反应规范起着更强有力的选择作用。
