2013/06/07 by Stephan Peischl, Peischl, Stephan, Mark Kirkpatrick +4 · 3 citations
Biochemistry, Genetics and Molecular Biology · Social Sciences · #Evolution and Genetic Dynamics #Evolutionary Game Theory and Cooperation #FOS: Biological sciences #Genetic diversity and population structure #Populations and Evolution (q-bio.PE)
paper · pdf · doi:10.48550/arxiv.1306.1652
openalex publication_date 2013/06/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the effect of spatial range expansions on the evolution of fitness when beneficial and deleterious mutations co-segregate. We perform individual-based simulations of a uniform linear habitat and complement them with analytical approximations for the evolution of mean fitness at the edge of the expansion. We find that deleterious mutations accumulate steadily on the wave front during range expansions, thus creating an expansion load. Reduced fitness due to the expansion load is not restricted to the wave front but occurs over a large proportion of newly colonized habitats. The expansion load can persist and represent a major fraction of the total mutation load thousands of generations after the expansion. Our results extend qualitatively and quantitatively to two-dimensional expansions. The phenomenon of expansion load may explain growing evidence that populations that have recently expanded, including humans, show an excess of deleterious mutations. To test the predictions of our model, we analyze patterns of neutral and non-neutral genetic diversity in humans and find an excellent fit between theory and data.