Spatial eco-evolutionary dynamics along environmental gradients: multi-stability and cluster dynamics

• Published in: Ecology letters 2019-05, Vol.22 (5), p.767-777
• Main Authors: Andrade-Restrepo, Martín, Champagnat, Nicolas, Ferrière, Régis
• Format: Article
• Language: English
• Subjects: Biodiversity; Life Sciences; Populations and Evolution
• ISSN: 1461-023X; 1461-0248

How the interplay of local adaptation and dispersal determines species appearance, distribution and range dynamics is still incompletely understood. Here we combine individual-based simulations and mathematical analysis of large-population approximation models to advance the analysis of spatial spread and phenotypic diversification of a single-species population along a one-dimensional resource gradient. Local competition shapes selection on heritable variation in the individual ecological trait (niche position) and the evolutionary response feeds back on the local ecological state of the population (abundance). Key parameters of spatial spread and phenotypic diversification are the individual dispersal rate, the size of the spatial competition neighborhood, and the phenotype mutational variance. From a focal location the population spreads by forming clusters in space and/or trait, or by spreading along a continuous cline in both space and trait. The conditions for clustering are broader than previously known. The spacing of clusters is determined by the spatial scale of competition. When the space-trait domain is bounded, multi-stability occurs, whereby small initial differences can lead to alternative spatial and trait distributions. The transient dynamics involve adaptational lags which cause a slow-down in cluster formation and population range expansion.