Stoehr Andrew M, Wojan Erin M
Department of Biological Sciences, Butler University, 4600 Sunset Avenue, Indianapolis, IN, 46208, USA.
Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA, 93407, USA.
Oecologia. 2016 Nov;182(3):691-701. doi: 10.1007/s00442-016-3694-2. Epub 2016 Jul 14.
Phenotypic plasticity, or the ability of organisms to produce different phenotypes depending upon environmental factors, may be adaptive in varying environments. However, because environments differ in many ways and organisms consist of many traits perfect phenotype-environment matches are unlikely. Studies that investigate multiple interacting environmental factors and the plastic responses of multiple traits should increase our understanding of the limits of adaptive plasticity. We experimentally examined the effects of variation in temperature and photoperiod on the seasonally plastic, and likely adaptive, melanization of a temperate butterfly, Pieris rapae. Although several melanin-based traits changed in response to temperature and photoperiodic variation, these traits tended to fall into two 'trait groups' consisting of traits covarying positively. However, these two trait groups responded to environmental factors, particularly temperature, in independent and sometimes opposing ways, with one increasing and the other decreasing in melanization with increased temperature. In some cases, plastic responses were complex and non-linear. Furthermore, when temperature and photoperiod were manipulated orthogonally, we sometimes detected interactive effects on melanization. These complex responses to two environmental cues may reflect sub-optimal responses or may occur if the two cues together provide more reliable information about future conditions than would either cue alone. Our results highlight the limits of studies of phenotypic plasticity that consider only single environmental factors and limit treatments to just two levels.
表型可塑性，即生物体根据环境因素产生不同表型的能力，在不同环境中可能具有适应性。然而，由于环境在许多方面存在差异，且生物体由许多性状组成，完美的表型 - 环境匹配不太可能实现。研究多个相互作用的环境因素以及多个性状的可塑性反应，应能增进我们对适应性可塑性极限的理解。我们通过实验研究了温度和光周期变化对温带蝴蝶菜粉蝶季节性可塑性且可能具有适应性的黑化的影响。尽管一些基于黑色素的性状随温度和光周期变化而改变，但这些性状倾向于分为两个“性状组”，组内性状呈正相关。然而，这两个性状组对环境因素，尤其是温度，以独立且有时相反的方式做出反应，随着温度升高，一个性状组的黑化程度增加，另一个则降低。在某些情况下，可塑性反应复杂且呈非线性。此外，当温度和光周期被正交操纵时，我们有时会检测到对黑化的交互作用。对这两种环境线索的这些复杂反应可能反映了次优反应，或者可能发生在这两种线索共同提供的关于未来条件的信息比单独任何一种线索更可靠的情况下。我们的结果突出了仅考虑单一环境因素且将处理限制在仅两个水平的表型可塑性研究的局限性。
