Department of Zoology, University of Cambridge, Cambridge, UK.
Department of Biodiversity, Abasaheb Garware College, Pune, Maharashtra, India.
J Evol Biol. 2021 Sep;34(9):1362-1375. doi: 10.1111/jeb.13895. Epub 2021 Jul 14.
Phenotypic plasticity in heterogeneous environments can provide tight environment-phenotype matching. However, the prerequisite is a reliable environmental cue(s) that enables organisms to use current environmental information to induce the development of a phenotype with high fitness in a forthcoming environment. Here, we quantify predictability in the timing of precipitation and temperature change to examine how this is associated with seasonal polyphenism in tropical Mycalesina butterflies. Seasonal precipitation in the tropics typically results in distinct selective environments, the wet and dry seasons, and changes in temperature can be a major environmental cue. We sampled communities of Mycalesina butterflies from two seasonal locations and one aseasonal location. Quantifying environmental predictability using wavelet analysis and Colwell's indices confirmed a strong periodicity of precipitation over a 12-month period at both seasonal locations compared to the aseasonal one. However, temperature seasonality and periodicity differed between the two seasonal locations. We further show that: (a) most females from both seasonal locations synchronize their reproduction with the seasons by breeding in the wet season but arresting reproduction in the dry season. In contrast, all species breed throughout the year in the aseasonal location and (b) species from the seasonal locations, but not those from the aseasonal location, exhibited polyphenism in wing pattern traits (eyespot size). We conclude that seasonal precipitation and its predictability are primary factors shaping the evolution of polyphenism in Mycalesina butterflies, and populations or species secondarily evolve local adaptations for cue use that depend on the local variation in the environment.
在异质环境中表现型可塑性可以提供紧密的环境-表现型匹配。然而，前提是存在可靠的环境线索，使生物能够利用当前的环境信息来诱导在即将到来的环境中具有高适应性的表现型的发展。在这里，我们量化了降水和温度变化时间的可预测性，以研究这如何与热带 Mycalesina 蝴蝶的季节性多态性相关。热带地区的季节性降水通常会导致不同的选择环境，即雨季和旱季，而温度变化可以成为主要的环境线索。我们从两个季节性地点和一个非季节性地点采样了 Mycalesina 蝴蝶群落。使用小波分析和 Colwell 指数量化环境可预测性，证实了两个季节性地点的降水在 12 个月期间都具有强烈的周期性，而与非季节性地点相比则具有周期性。然而，两个季节性地点的温度季节性和周期性存在差异。我们进一步表明：(a) 来自两个季节性地点的大多数雌性通过在雨季繁殖而与季节同步，但在旱季停止繁殖。相比之下，所有物种在非季节性地点全年都进行繁殖，(b) 季节性地点的物种，但不是非季节性地点的物种，表现出翅膀图案特征（眼斑大小）的多态性。我们得出结论，季节性降水及其可预测性是塑造 Mycalesina 蝴蝶多态性进化的主要因素，而种群或物种则会根据环境的局部变化，进化出对线索利用的局部适应性。
