Adaptation of timing of life history traits and population dynamic responses to climate change in spatially structured populations

Abstract

Changes in the seasonal timing of life history events are documented effects of climate change. We used a general model to study how dispersal and competitive interactions affect eco-evolutionary responses to changes in the temporal distribution of resources over the season. Specifically, we modeled adaptation of the timing of reproduction and population dynamic responses in two competing populations that disperse between two habitats characterized by an early and late resource peak. We investigated three scenarios of environmental change: (1) food peaks advance in both habitats, (2) in the late habitat only and (3) in the early habitat only. At low dispersal rates the evolutionarily stable timing of reproduction closely matched the local resource peak and the environmental change typically caused population decline. Larger dispersal rates rendered less intuitive ecoevolutionary population responses. First, dispersal caused mismatch between evolutionarily stable timing of reproduction and local resource peaks and as a result, reproductive output for subpopulations could increase as well as decrease when resource availability underwent temporal shifts. Second, population responses were contingent on competition between populations. This could accelerate population declines and cause extinctions or even reverse population trends from negative to positive compared to the low dispersal case. When dispersal rate was large and the early resource peak was advanced available niche space was reduced. Hence, even when a population survived the environmental change and obtained positive equilibrium population density, subsequent adaptation of competing populations could drive it to extinction due to convergent evolution and competitive exclusion. These results shed new light on the role of competition and dispersal for the evolution of timing of life history events and provide guidelines for understanding short and long-term population response to climate change.

Consistent differences in fitness traits across multiple generations of Olympia oysters

“…In particular, up to 10 fold less chlorophyll a has been observed in Fidalgo Bay compared to the other sites. The proposed trade-off in energy allocation for this population could be driven by selection from such environmental differences in the quantity and timing of food supply 39 , 40 . As mentioned previously, selection could act through local adaptation or phenotype-environment mismatch, depending on the spatial scale of dispersal relative to the scale of environmental heterogeneity.…”

The importance of network spatial structure as a driver of eco‐evolutionary dynamics

“…Understanding the factors contributing to gene flow necessitates a consideration of the factors contributing to dispersal, including the spatial structure of populations. Many theoretical studies assumed simple spatial structures like a linear environment (Andrade‐Restrepo et al 2019), two demes (Pontarp et al 2015), or populations structured as grid cells, with equal size and distance among them (Schiffers et al 2013). However, other experimental and theoretical studies with more complex spatial structure of populations have revealed that spatial structure has a major influence on demography, including potential consequences for metapopulation persistence (Vuilleumier et al 2007, Gilarranz and Bascompte 2012, De Roissart et al 2015), synchrony (Yeakel et al 2014, Larsen et al 2021), or metacommunity biodiversity (Carrara et al 2014).…”