Predictability of temporal variation in climate and the evolution of seasonal polyphenism in tropical butterfly communities

다국어 초록 (Multilingual Abstract)

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.
One of the core pre‐requisites for maintaining adaptive phenotypic plasticity is that the environment should be predictable. We tested this hypothesis by sampling three communities of Mycalesina butterflies, where many species exhibit seasonal polyphenism, from two seasonal and one aseasonal location. By quantifying environmental predictability and phenotypic traits from field collected samples, we show that predictability in seasonal precipitation than temperature, a putative environmental cue, is the primary factor shaping the evolution of seasonal polyphenism in Mycalesina butterflies.