Parallel Evolution in Ecological and Reproductive Traits to Produce Cryptic Damselfly Species Across the Holarctic

Abstract

The damselfly genus Enallagma originated in the Nearctic, and two Nearctic lineages recently underwent radiations partly associated with multiple independent habitat shifts from lakes dominated by fish predators into lakes dominated by dragonfly predators. A previous molecular study of four Palearctic morphospecies and all representative Nearctic species identified the presence of two cryptic species sets, with each set having Palearctic and Nearctic representatives. However, the cryptic species within each set are not sibling species. Here, we present quantitative data on ecologically important larval morphologies and behaviors involved in predator avoidance and on adult male morphological structures involved in mate recognition to quantify the phenotypic relationships among these cryptic species sets. For the adult stage, our data indicate strong parallel evolution of the structures involved in specific mate recognition-the male cerci. For the larval stage, morphometric analyses show that the Palearctic species evolved a nearly identical morphology to the sibling-clade members in the Nearctic that live in waters where dragonflies are the top predators. This implicates the importance of dragonfly predation in the history of the Palearctic clade. Behavioral analyses suggest population differentiation in response to the actual predator environment in the Palearctic clade, consistent with the species differentiation seen in the Nearctic. Our results suggest parallel evolution of adult traits that influence specific mate choice and larval traits that influence ecological performance underlie the striking similarity of Enallagma species across continents. This concurrent parallel evolution in both stages of a complex life cycle, especially when both stages do not share the same selective environment, may be a very unusual mechanism generating cryptic species.

Internest food sharing within wood ant colonies: resource redistribution behavior in a complex system

“…Polydomy may, therefore, provide an interesting variation on the idea of behavioral convergence. Behavioral convergence is the repeated evolution of the same behavioral traits by species in similar environments (e.g., Blackledge and Gillespie 2004 ; Stoks et al 2005 ; Johnson et al 2010 ; Alejandrino et al 2011 ). In the case of polydomy, rather than the behavior evolving multiple times in response to similar ecological conditions, the same behavior may have evolved multiple times in response to a variety of different ecological conditions, due to an inherent predisposition for the behavior.…”

A Tale of Two Diversifications: Reciprocal Habitat Shifts to Fill Ecological Space along the Pond Permanence Gradient

“…Based on previous mass) Ϫ log (initial wet mass)]/4 e wet mass-to-dry mass regressions, we assumed that dry mass (McPeek 2004). Previous anal-mass p 0.15 # wet Stoks et al (2005b).…”

“…Functional studies have also identified ecologically important phenotypes that limit the distributions of species along this gradient and that influence population regulation (Pierce et al 1985;McPeek 1990aMcPeek , 1995aMcPeek , 1999McPeek , 2004McPeek et al 1996;Stoks and McPeek 2003a;Stoks et al 2003). Previous analyses have explored the diversification of Enallagma throughout the Holarctic (e.g., McPeek and Brown 2000;Stoks et al 2005b). Here, we focus on Lestes diversification and the comparison of the two genera in eastern North America, where most of our ecological work has been done.…”

Convergent and parallel evolution in life habit of the scallops (Bivalvia: Pectinidae)

“…To a lesser extent, similar work has been done in invertebrate groups, specifically arthropods. For example, convergent or parallel evolution has been identified in replicated shifts of host use in insects [21,22], web construction in arachnids [8], larval morphology and antipredator behavior in aquatic insects [23], and adult morphology in barnacles [24]. Outside of arthropods, few studies using invertebrates explicitly test for convergence and parallelism (but see gastropods: [25,26]; bivalves: [27]).…”