Evolution reverses the effect of network structure on metapopulation persistence

Abstract

Global environmental change is challenging species with novel conditions, such that demographic and evolutionary trajectories of populations are often shaped by the exchange of organisms and alleles across landscapes. Current ecological theory predicts that random networks with dispersal shortcuts connecting distant sites can promote persistence when there is no capacity for evolution. Here, we show with an eco‐evolutionary model that dispersal shortcuts across environmental gradients instead hinder persistence for populations that can evolve because long‐distance migrants bring extreme trait values that are often maladaptive, short‐circuiting the adaptive response of populations to directional change. Our results demonstrate that incorporating evolution and environmental heterogeneity fundamentally alters theoretical predictions regarding persistence in ecological networks.

Evolution and connectivity influence the persistence and recovery of coral reefs under climate change in the Caribbean, Southwest Pacific, and Coral Triangle

“…The positive effect of destination strength likely operated through the ecological effects of larval immigration, implying that the demographic benefits of connectivity outweighed the potential negative evolutionary effects of gene swamping (Lenormand, 2002 ). Furthermore, the negative effect of initial SST was likely due to warmer reefs receiving cold‐adapted larvae: as the network warmed, cold‐adapted larvae arriving in relatively warm reefs counteracted evolutionary adaptation (McManus et al, 2021 ; Norberg et al, 2012 ).…”

“…Within each region, coral subpopulations exchanged larvae based on previously published biophysical model outputs (Schill et al, 2015 ; Thompson et al, 2018 ; Treml et al, 2008 ) and evolved in response to changing temperatures. To explore the role of ecological versus evolutionary dynamics on regional and local coral populations, we simulated metapopulation dynamics with different levels of standing genetic variation, which sets evolutionary potential (McManus et al, 2021 ; Norberg et al, 2012 ; Walsworth et al, 2019 ). Finally, we constructed general linear models to interpret the influence of patch‐level metrics on the minimum coral cover experienced on a reef.…”

“…We applied an eco‐evolutionary model (McManus et al, 2021 ) forced with temperature projections and larval connectivity patterns in the Caribbean, SWP, and CT coral reef regions. Because reefs are typically considered as distinct habitat patches, we incorporated a novel extension to a continuous‐space metapopulation dynamics framework to allow for immigration during the larval phase according to a connectivity matrix D that quantifies dispersal connections in each region (described below).…”

“…In addition to population dynamics, change in coral cover through time was affected by the dispersal of coral larvae across the network. Our model differed from previous frameworks because we incorporated spatially explicit dispersal among patches (McManus et al, 2021 ) instead of a diffusion approximation (Norberg et al, 2012 ; Walsworth et al, 2019 ). Overall, there was higher settlement when there was more free space (i.e., F a >> 0, see Equation 1 ) and a patch without free space ( F a = 0) had a settlement rate of zero.…”

Individual-based eco-evolutionary models for understanding adaptation in changing seas

“…The spatial configuration of dispersal networks can impact adaptation by shaping the distribution of adaptive genetic variation among subpopulations [36]. For many marine systems, the scale and degree of dispersal are governed by physical oceanography [58].…”