Phenotypic plasticity in the range-margin population of the lycaenid butterfly Zizeeria maha

Abstract

BackgroundMany butterfly species have been experiencing the northward range expansion and physiological adaptation, probably due to climate warming. Here, we document an extraordinary field case of a species of lycaenid butterfly, Zizeeria maha, for which plastic phenotypes of wing color-patterns were revealed at the population level in the course of range expansion. Furthermore, we examined whether this outbreak of phenotypic changes was able to be reproduced in a laboratory.ResultsIn the recently expanded northern range margins of this species, more than 10% of the Z. maha population exhibited characteristic color-pattern modifications on the ventral wings for three years. We physiologically reproduced similar phenotypes by an artificial cold-shock treatment of a normal southern population, and furthermore, we genetically reproduced a similar phenotype after selective breeding of a normal population for ten generations, demonstrating that the cold-shock-induced phenotype was heritable and partially assimilated genetically in the breeding line. Similar genetic process might have occurred in the previous and recent range-margin populations as well. Relatively minor modifications expressed in the tenth generation of the breeding line together with other data suggest a role of founder effect in this field case.ConclusionsOur results support the notion that the outbreak of the modified phenotypes in the recent range-margin population was primed by the revelation of plastic phenotypes in response to temperature stress and by the subsequent genetic process in the previous range-margin population, followed by migration and temporal establishment of genetically unstable founders in the recent range margins. This case presents not only an evolutionary role of phenotypic plasticity in the field but also a novel evolutionary aspect of range expansion at the species level.

Novel variation associated with species range expansion

“…As the climate has warmed, this turn-over has resulted in expansions that appear more permanent. Consistent northward range shifts have been documented for several vertebrate and invertebrate species in the northern hemisphere, but particularly Lepidoptera, whose historical distributions are usually well-known [1,2]. But what do colonizers look like in these new populations - are they just a sample of the main population or do they differ phenotypically or genotypically?…”

Self-Similarity, Distortion Waves, and the Essence of Morphogenesis: A Generalized View of Color Pattern Formation in Butterfly Wings

“…It is worth noting that temperature treatments (Nijhout 1984) and pharmacological treatments (Otaki 1998(Otaki , 2008aSerfas and Carroll 2005) are the only means that can efficiently create this "artificial rearrangement of elements" or "elemental transformation," which is reminiscent of evolutionary trial and error to invent new color patterns based on the nymphalid ground plan. These color pattern modifications are evolutionarily and physiologically relevant (Hiyama et al 2012;Otaki and Yamamoto 2004a, b;Otaki et al 2005bOtaki et al , 2006Otaki et al , 2010Otaki 2007Otaki , 2008bMahdi et al 2010Mahdi et al , 2011, justifying their use as an important method to construct a formal model. The threshold change model is the most popular interpretation of the TS-type modifications (Otaki 1998(Otaki , 2008aSerfas and Carroll 2005) as well as of physically induced modifications (Nijhout 1980a(Nijhout , 1985Brakefield 1992, 1995;Brakefield and French 1995).…”

“…I have examined the color pattern modifications induced by temperature shock or pharmacological treatments (collectively called the TS-type modifications) (Hiyama et al 2012;Otaki and Yamamoto 2004a, b;Otaki et al 2005bOtaki et al , 2006Otaki et al , 2010Otaki 2007Otaki , 2008bMahdi et al 2010Mahdi et al , 2011 (Fig. 7.7a).…”

A Geometric Morphometric Study of the Wing Shapes ofPieris rapae(Lepidoptera: Pieridae) from the Qinling Mountains and Adjacent Regions: An Environmental and Distance-Based Consideration

“…Under certain environmental conditions, changes in an organism's phenotype can increase its fitness, and thus organisms exhibit the capacity to adjust their phenotype to match prevailing local conditions (Merckx & Van Dyck 2006;Monaghan 2008;Otaki et al 2010). Recently, the effects of environmental factors on the shapes of organisms, as well as the interactions of these elements, have been extensively examined (Beldade & Brakefield 2002;Prieto & Dahners 2009).…”