Adaptive traits are maintained on steep selective gradients despite gene flow and hybridization in the intertidal zone.

ABSTRACT: Gene flow among hybridizing species with incomplete reproductive barriers blurs species boundaries, while selection under heterogeneous local ecological conditions or along strong gradients may counteract this tendency. Congeneric, externally-fertilizing fucoid brown algae occur as distinct morphotypes along intertidal exposure gradients despite gene flow. Combining analyses of genetic and phenotypic traits, we investigate the potential for physiological resilience to emersion stressors to act as an isolating mechanism in the face of gene flow. Along vertical exposure gradients in the intertidal zone of Northern Portugal and Northwest France, the mid-low shore species Fucus vesiculosus, the upper shore species Fucus spiralis, and an intermediate distinctive morphotype of F. spiralis var. p

SUBMITTER: Zardi GI 

PROVIDER: S-EPMC3114782 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature