Effects of genotypic and phenotypic variation on establishment are important for conservation, invasion, and infection biology

Abstract

There is abundant evidence that the probability of successful establishment in novel environments increases with number of individuals in founder groups and with number of repeated introductions. Theory posits that the genotypic and phenotypic variation among individuals should also be important, but few studies have examined whether founder diversity influences establishment independent of propagule pressure, nor whether the effect is model or context dependent. I summarize the results of 18 experimental studies and report on a metaanalysis that provides strong evidence that higher levels of genotypic and phenotypic diversity in founder groups increase establishment success in plants and animals. The effect of diversity is stronger in experiments carried out under natural conditions in the wild than under seminatural or standardized laboratory conditions. The realization that genetic and phenotypic variation is key to successful establishment may improve the outcome of reintroduction and translocation programs used to vitalize or restore declining and extinct populations. Founder diversity may also improve the ability of invasive species to establish and subsequently spread in environments outside of their native community, and enhance the ability of pathogens and parasites to colonize and invade the environment constituted by their hosts. It is argued that exchange of ideas, methodological approaches, and insights of the role of diversity for establishment in different contexts may further our knowledge, vitalize future research, and improve management plans in different disciplines.colonization | biological invasion | biodiversity | extinction

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

“…The adaptive evolution of polymorphisms, including trophic polymorphisms and sexual dimorphisms, can spread various fitness costs (for example, resource limitation) or reduce the overall genetic load of a population 14,15,[25][26][27][28][29][30] . Polymorphic systems that we studied here can illustrate evolutionary overcomes of the tragedy of the commons, in which males exploit females as common resources and thereby reduce population productivity.…”

Intraspecific Trait Variation Is Correlated with Establishment Success of Alien Mammals

“…Those studies that have explored the role of variation in animals have focused on single alien species (Dybdahl and Kane 2005;Engel et al 2011;Knop and Reusser 2012;Zalewski and Bartoszewicz 2012), likely because capturing intraspecific variation requires additional research and data compilation efforts, which have limited the availability of variation estimates for comparative studies. The exception is a very recent meta-analysis that shows invasive species (including plants, invertebrates, and one fish) exhibit higher genetic and phenotypic variation than noninvasive species (Forsman 2014). However, the potential role of intraspecific variation as a determinant of establishment success of terrestrial vertebrates remains unexplored.…”

“…Additionally, species with high intraspecific trait variation may also be better able to establish in novel environments because diverse individuals are potentially preadapted to a wider range of environmental conditions. Indeed, experimental data show that more variable founder groups are more likely to successfully establish in novel natural environments (Forsman 2014). Finally, although variation can be beneficial, it should be noted that not all variation must necessarily lead to increased establishment success or persistence (Robinson et al 2013).…”

Invasive plants have broader physiological niches

“…Such uncertainty is perhaps not surprising, because the study of invasions is, by definition, complicated by historical factors. For example, increased propagule pressure and residence time increase invasive success, together often overwhelming any inherent factors that enhance or limit invasiveness (12)(13)(14). Hence, invasion biology seems resigned to accepting that a universal definition of invasibility and invasiveness is unlikely and that case-specific solutions are all that can be achieved (9).…”