Dispersal and life-history traits in a spider with rapid range expansion

Abstract

Background: Dispersal and reproduction are key life-history traits that jointly determine species' potential to expand their distribution, for instance in light of ongoing climate change. These life-history traits are known to be under selection by changing local environmental conditions, but they may also evolve by spatial sorting. While local natural selection and spatial sorting are mainly studied in model organisms, we do not know the degree to which these processes are relevant in the wild, despite their importance to a comprehensive understanding of species' resistance and tolerance to climate change. Methods: The wasp spider Argiope bruennichi has undergone a natural range expansion-from the Mediterranean to Northern Europe during the recent decades. Using reciprocal common garden experiments in the laboratory, we studied differences in crucial traits between replicated core (Southern France) and edge (Baltic States) populations. We tested theoretical predictions of enhanced dispersal (ballooning behaviour) and reproductive performance (fecundity and winter survival) at the expansion front due to spatial sorting and local environmental conditions. Results: Dispersal rates were not consistently higher at the northern expansion front, but were impacted by the overwintering climatic conditions experienced, such that dispersal was higher when spiderlings had experienced winter conditions as occur in their region. Hatching success and winter survival were lower at the range border. In agreement with theoretical predictions, spiders from the northern leading edge invested more in reproduction for their given body size. Conclusions: We found no evidence for spatial sorting leading to higher dispersal in northern range edge populations of A. bruennichi. However, reproductive investment and overwintering survival between core and edge populations differed. These life-history traits that directly affect species' expansion rates seem to have diverged during the recent range expansion of A. bruennichi. We discuss the observed changes with respect to the species' natural history and the ecological drivers associated with range expansion to northern latitudes.

Landscape connectivity alters the evolution of density-dependent dispersal during pushed range expansions

“…5, Supplementary Material S2). While clear increases in average dispersal or per capita growth rates are often expected at the edge of range expansions (Chuang & Peterson, 2016;Fronhofer et al, 2017;Phillips & Perkins, 2019;Van Petegem et al, 2018;Weiss-Lehman et al, 2017), there are enough exceptions to the "rule" (Chuang & Peterson, 2016;Van Petegem et al, 2018;Wolz et al, 2020) for these null/uncertain results not to be entirely surprising by themselves.…”

“…Both models and reshuffling experiments (where individuals’ locations are regularly randomized to stop spatial evolution) have demonstrated how these evolutionary changes can accelerate expansions (Perkins et al, 2013; Schreiber & Beckman, 2020; J. M. Travis & Dytham, 2002; Van Petegem et al, 2018; Weiss-Lehman et al, 2017). However, summarizing empirical studies also shows that these directional shifts in population growth, dispersal or associated traits do not always happen during range expansions (Chuang & Peterson, 2016; Merwin, 2019; Van Petegem et al, 2018; Wolz et al, 2020). We need a better understanding of what determines whether or not this spatial selection will occur, and whether it will affect growth traits or dispersal traits, if we want to successfully predict (and potentially manage) the ecological and evolutionary dynamics of range expansions or shifts.…”

Chromosome-level reference genome of the European wasp spiderArgiope bruennichi: a resource for studies on range expansion and evolutionary adaptation

“…However, it is not yet known which regions of the genome are admixed and whether these regions are truly responsible for adaptation to colder climates. A. bruennichi has also been well studied in the context of dispersal and life history traits [ 39 ], as well as sexual selection and chemical communication (e.g., [ 40–44 ]). A high-quality reference genome would allow new insights into our understanding of the genetic basis of these phenomena.…”

Editorial: thematic series “Integrating movement ecology with biodiversity research”

“…The two remaining contributions address evolutionary aspects. Wolz et al [28] compare traits characterizing dispersal and reproduction of a predatory wasp spider in its core populations (Southern France) and those in Baltic States to where the species'range expanded over the recent decades. The question was whether this range expansion was related to evolutionary changes in dispersal.…”