Spatial scale of local adaptation and population genetic structure in a miniature succulent, Argyroderma pearsonii.
Explicit understanding of the spatial scale of evolutionary processes is required in order to set targets for their effective conservation. Here, we explore the spatial context of neutral and adaptive divergence in the species-rich Knersvlakte region of South Africa. Specifically, we aimed to assess the importance of erosional drainage basins as spatial units of evolutionary process. We used amplified fragment length polymorphism (AFLP) and reciprocal transplants to investigate genetic differentiation in Argyroderma pearsonii, sampled from sparse and dense quartz habitats within each of three drainage basins. This design allowed assessment of differentiation at two distinct spatial scales; between habitats within basins, and between basins. We found near-perfect concordance between genetic clusters and basin occupancy, suggesting restricted interbasin gene flow. In addition, transplants reveal adaptive divergence between basins on the dense quartz habitat. We have shown that neutral and adaptive differentiation occurs between basins, but not between habitats within basins, suggesting that conservation plans aimed at conserving multiple interconnected drainage basins will capture an important axis of evolutionary process on the Knersvlakte.
Ellis
Allan G
AG
Department of Ecology and Evolutionary Biology, 321 Steinhaus Hall, University of California, Irvine, CA 92697, USA.|Leslie Hill Institute for Plant Conservation, Botany Department, University of Cape Town, Rondebosch 7701, South Africa.|Present address: Department of Biological and Conservation Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, PMB 3209, South Africa.
Weis
Arthur E
AE
Department of Ecology and Evolutionary Biology, 321 Steinhaus Hall, University of California, Irvine, CA 92697, USA.
Gaut
Brandon S
BS
Department of Ecology and Evolutionary Biology, 321 Steinhaus Hall, University of California, Irvine, CA 92697, USA.
D000064:Acclimatization; D035722:Aizoaceae / Q000235:genetics* / Q000254:growth & development; D002980:Climate; D017753:Ecosystem; D035264:Flowers / Q000235:genetics; D017343:Genes, Plant; D008957:Models, Genetic; D011058:Pollen / Q000235:genetics; D011156:Population Density; D013019:South Africa; D014881:Water Supply