Testing the evolutionary species interactions - abiotic stress hypothesis – E-SIASH

Objective 1 is being addressed by using individual-based, eco-evolutionary simulation models. Specifically, we take into account the evolution of dispersal, the evolution of local adaptation, that is, evolution of the niche, and concurrent changes in correlated life-history traits. These evolutionary factors are all central drivers of range dynamics. Objective 2 involves microbial model systems which are unique and ideal for highly controlled proof-of-concept experimental tests of theory involving large spatial and/or temporal scales.

While empirical work is currently ongoing, first theoretical results highlight the importance of second order evolutionary processes in determining the impact of evolution of range dynamics.

In the remaining time of the project we will finalize theoretical analyses and focus on empirical testing.

First results will be presented during VirtualEvolution 2021.

Why do we observe species occurring in certain habitats but not in others? Since the days of Darwin researchers debate this fundamental question and the relative role of environment versus species’ interactions in driving species distribution patterns. Summarized as the “Species Interactions – Abiotic Stress Hypothesis” (SIASH), theory suggests that abiotic forces set range boundaries under stressful conditions, while biotic interaction are most relevant in benign environments. While central to basic and applied research this hypothesis 1) lacks the integration of contemporary evolution and 2) remains largely untested empirically. Therefore, this project follows two complementary objectives: 1) Expansion and update of theory to include eco-evolutionary feedbacks, i.e., evolution of dispersal, local adaptation and correlated life-history traits, which are central drivers of range dynamics. 2) Experimental testing in microbial model landscapes subject to a temperature gradient using experimental evolution and protists as model organisms.