Dispersal plasticity driven by variation in fitness across species and environmental gradients

Abstract

Dispersal plasticity, when organisms adjust their dispersal decisions depending on their environment, can play a major role in ecological and evolutionary dynamics, but how it relates to fitness remains scarcely explored. Theory predicts that high dispersal plasticity should evolve when environmental gradients have a strong impact on fitness. Using microcosms, we tested in five species of the genus Tetrahymena whether dispersal plasticity relates to differences in fitness sensitivity along three environmental gradients. Dispersal plasticity was species-and environment-dependent. As expected, dispersal plasticity was generally related to fitness sensitivity, with higher dispersal plasticity when fitness is more affected by environmental gradients. Individuals often preferentially disperse out of low fitness environments, but leaving environments that should yield high fitness was also commonly observed. We provide empirical support for a fundamental, but largely untested, assumption in dispersal theory: the extent of dispersal plasticity correlates with fitness sensitivity to the environment.

Experimental evolution of dispersal: Unifying theory, experiments and natural systems

“…On a final note, interdisciplinary studies are also a promising approach to examine (evolutionary changes in) dispersal plasticity under different environmental conditions (Campana et al, 2022).…”

“…On a final note, interdisciplinary studies are also a promising approach to examine (evolutionary changes in) dispersal plasticity under different environmental conditions (Campana et al, 2022). Meta‐population experiments have recently shown that dispersal plasticity is impacted by top‐down and bottom‐up effects (Cote et al, 2022; Fronhofer et al, 2018) including potential consequences for meta‐foodweb stability.…”

Ecological selection of dispersal strategies in metacommunities: impact of landscape features and competitive dynamics

“…Dispersal decisions are context-dependent (plastic), meaning that organisms adjust them based on information about the surrounding biotic (e.g., predation, kin competition, and intra- and interspecific-competition) and abiotic (e.g., resource availability, spatiotemporal environmental variation) conditions [15]. For instance, organisms are more propense to leave their natal patches when local performance (i.e., fitness) is reduced via strong competition (intraspecific or interspecific), predation, resource scarcity, or unsuitable abiotic conditions [7,16]. These context-dependent decisions underly changes in species’ dispersal strategies to maximize regional fitness and/or minimize local mortality across different ecological contexts.…”

“…Lastly, context-dependent variation in dispersal strategies are species-specific [6,8,16]. Thus, even species that are evolutionary closely related may still exhibit contrasting changes in dispersal strategies when subjected to varying abiotic and biotic conditions [8,16].…”

“…These contextdependent decisions underly changes in species' dispersal strategies to maximize regional fitness and/or minimize local mortality across different ecological contexts. Lastly, context-dependent variation in dispersal strategies are species-specific [6,8,16]. Thus, even species that are evolutionary closely related may still exhibit contrasting changes in dispersal strategies when subjected to varying abiotic and biotic conditions [8,16]..…”