title: Speciation on a local geographic scale: the evolution of a rare rock outcrop specialist in Mimulus.
abstract: Speciation can occur on both large and small geographical scales. In plants, local speciation, where small populations split off from a large-ranged progenitor species, is thought to be the dominant mode, yet there are still few examples to verify speciation has occurred in this manner. A recently described morphological species in the yellow monkey flowers, Mimulus filicifolius, is an excellent candidate for local speciation because of its highly restricted geographical range. Mimulus filicifolius was formerly identified as a population of M. laciniatus due to similar lobed leaf morphology and rocky outcrop habitat. To investigate whether M. filicifolius is genetically divergent and reproductively isolated from M. laciniatus, we examined patterns of genetic diversity in ten nuclear and eight microsatellite loci, and hybrid fertility in M. filicifolius and its purported close relatives: M. laciniatus, M. guttatus and M. nasutus. We found that M. filicifolius is genetically divergent from the other species and strongly reproductively isolated from M. laciniatus. We conclude that M. filicifolius is an independent rock outcrop specialist despite being morphologically and ecologically similar to M. laciniatus, and that its small geographical range nested within other wide-ranging members of the M. guttatus species complex is consistent with local speciation.
authors: Department of Biology, Duke University, 125 Science Drive, Durham, NC 27708, USA kgferris@gmail.com.
authors: Kathleen G
authors: KG
authors: Ferris
authors: School of Natural Sciences, University of California Merced, 5200 North Lake Road, Merced, CA 95343, USA.
authors: Jason P
authors: JP
authors: Sexton
authors: Department of Biology, Duke University, 125 Science Drive, Durham, NC 27708, USA.
authors: John H
authors: JH
authors: Willis
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics*; D000704:Analysis of Variance; D005075:Biological Evolution; D002140:California; D017753:Ecosystem; D056426:Genetic Loci / Q000235:genetics; D049810:Genetic Speciation; D014644:Genetic Variation; D059646:Genome Size / Q000235:genetics; D005843:Geography; D006824:Hybridization, Genetic; D018895:Microsatellite Repeats / Q000235:genetics; D032241:Mimulus / Q000033:anatomy & histology / Q000235:genetics* / Q000502:physiology; D063148:Plant Dispersal; D016133:Polymerase Chain Reaction; D025341:Principal Component Analysis; D012098:Reproduction / Q000502:physiology; D060047:Reproductive Isolation; D013045:Species Specificity
keywords: Mimulus filicifolius; Mimulus guttatus; Mimulus laciniatus; genetics; local speciation; rock outcrops