Dispersal ability explains genetic and community patterns in Sonoran Desert streams

Authors: David A. Lytle, Miguel Canedo-Arguelles, Tiffany A. Schriever, Emily E. Hartfield Kirk, Michael T. Bogan, Kate S. Boersma, Meryl E. Mims, Julian D. Olden

Year: 2014 (xlvi)

Abstract

Population genetic and community processes are governed by fundamentally different mechanisms, yet both take place in a single landscape with characteristic site-specific, local, and regional attributes. We characterized aquatic invertebrate communities from 28 sites spanning 7 aridland streams in SE Arizona, U.S.A. over 3 years. We also genotyped populations of aquatic insects that differed greatly in dispersal ability: a weak-disperser giant water bug (20 populations), a moderate-disperser stonefly (34 populations), and a strong-disperser beetle (31 populations). Using landscape genetics methods, we found that only stonefly populations showed a significant isolation-by-distance pattern across the landscape. Water bug populations were randomly differentiated due to genetic drift, and beetle population structure was eliminated by panmixia. After characterizing species by dispersal traits, community data revealed an analogous pattern. Only moderate-disperser community structure was explainable by landscape variables; weak-disperser community structure was dominated by site-specific environmental filters, and strong dispersers showed no pattern. Our results suggest that although evolutionary and ecological processes are distinct, the interaction between dispersal ability and landscape is a common cause underlying both.

Resumen

Entra texto de resumen en espaÃ±ol