title: Microgeographic adaptation and the spatial scale of evolution.
abstract: Local adaptation has been a major focus of evolutionary ecologists working across diverse systems for decades. However, little of this research has explored variation at microgeographic scales because it has often been assumed that high rates of gene flow will prevent adaptive divergence at fine spatial scales. Here, we establish a quantitative definition of microgeographic adaptation based on Wright's dispersal neighborhood that standardizes dispersal abilities, enabling this measure to be compared across species. We use this definition to evaluate growing evidence of evolutionary divergence at fine spatial scales. We identify the main mechanisms known to facilitate this adaptation and highlight illustrative examples of microgeographic evolution in nature. Collectively, this evidence requires that we revisit our understanding of the spatial scale of adaptation and consider how microgeographic adaptation and its driving mechanisms can fundamentally alter ecological and evolutionary dynamics in nature.
authors.affiliation: Department of Ecology & Evolutionary Biology, University of Connecticut, Storrs, CT 06269 USA. Electronic address: jrichardson@uconn.edu.
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Richardson
authors.affiliation: Department of Ecology & Evolutionary Biology, University of Connecticut, Storrs, CT 06269 USA.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Urban
authors.affiliation: Howard Hughes Medical Institute & Section of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Bolnick
authors.affiliation: School of Forestry & Environmental Studies, Yale University, New Haven, CT 06511, USA.
authors.forename: David K
authors.initials: DK
authors.lastname: Skelly
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000818:Animals; D044822:Biodiversity; D005075:Biological Evolution; D003710:Demography