Evolution of increased phenotypic diversity enhances population performance by reducing sexual harassment in damselflies

Abstract

The effect of evolutionary changes in traits and phenotypic/genetic diversity on ecological dynamics has received much theoretical attention; however, the mechanisms and ecological consequences are usually unknown. Female-limited colour polymorphism in damselflies is a counter-adaptation to male mating harassment, and thus, is expected to alter population dynamics through relaxing sexual conflict. Here we show the side effect of the evolution of female morph diversity on population performance (for example, population productivity and sustainability) in damselflies. Our theoretical model incorporating key features of the sexual interaction predicts that the evolution of increased phenotypic diversity will reduce overall fitness costs to females from sexual conflict, which in turn will increase productivity, density and stability of a population. Field data and mesocosm experiments support these model predictions. Our study suggests that increased phenotypic diversity can enhance population performance that can potentially reduce extinction rates and thereby influence macroevolutionary processes.

Intralocus Sexual Conflict and the Tragedy of the Commons in Seed Beetles

“…Rather than being counter to our other results implicating IaSC and male adaptations as drivers of population decline, this finding could be related to IeSC, if females that are more male-like evade costly male attention. Indeed, it makes sense that such an effect could be driven by variation in a conspicuous trait such as color pigmentation (as seen in other insects: e.g., Takahashi et al 2014), as opposed to the more cryptic life-history variation. The link between SD in color pigmentation and IeSC is also consistent with male harassment of females being pronounced in this species and causing significant reductions in female life span (e.g., Maklakov and Bonduriansky 2009), as well as with the male genitalia, by successive remating, causing potentially severe damage to the female reproductive tract (Hotzy and Arnqvist 2009).…”

“…This interlocus sexual conflict (IeSC) often causes males to inflict direct harm on females during mating interactions, reducing female fecundity and overall population viability (Arnqvist and Rowe 2005). Indeed, the evolution of male reproductive strategies can result in a so-called tragedy of the commons (sensu Hardin 1968), where male traits that increase fertilization success, such as genital morphology and aggressive behaviors, evolve despite a substantial cost to the population as a whole (Holland and Rice 1999;Kokko and Brooks 2003;Rankin and Lopez-Sepulcre 2005;Eldakar et al 2010;Rankin et al 2011;Plesnar-Bielak et al 2012;Takahashi et al 2014;Chenoweth et al 2015).…”

Molecular Mechanisms Underlying Color Vision and Color Formation in Dragonflies

“…17.1g, h), sex-specific color formation is regulated cell-autonomously in dragonflies. In many dragonfly species, adult body color plays important roles in partner recognition (Corbet 1999;Svensson et al 2007;Córdoba-Aguilar 2008;Svensson et al 2014;Takahashi et al 2014;Beatty et al 2015;Drury et al 2015). Interspecific or male-male connection has sometimes been observed in the field between similar-colored individuals , and interspecific hybrids has been reported occasionally (Corbet 1999;Futahashi 1999;Futahashi and Futahashi 2007;Moriyasu and Sugimura 2007;Ozono et al 2012;Sánchez-Guillén et al 2014;Futahashi 2016a).…”

On reciprocal causation in the evolutionary process

“…Empirically, NFDS has been identified and studied in several field and laboratory systems, and it is a dynamic research field that has grown out of SET (Sinervo and Lively 1996;Sinervo et al 2000;Svensson et al 2005;Neff and Svensson 2013;Zhang et al 2013;Le Rouzic et al 2015). The importance of NFDS is by no means restricted to its role in maintaining genetic polymorphisms within local populations, but it can also affect population performance such as stability, productivity or extinction risk (Takahashi et al 2014). Negative frequency-dependence might also be an important process in community ecology, where it can preserve biodiversity through rare-species advantages (Wills et al 2006).…”