title: Morphological and genetic discrepancies in populations of Oreocarya paradoxa and O. revealii: the impact of edaphic selection on recent diversification in the Colorado Plateau.
abstract: OBJECTIVE
  Investigations of recently derived and edaphically (soil) defined plant systems have provided insight into important mechanisms of ecological divergence. We investigated the impact of edaphic adaptation on recent divergence between two Colorado Plateau endemics: the gypsum facultative Oreocarya revealii (Boraginaceae) and its more generalist sister species O. paradoxa. We assessed morphological stability, genetic identity, and soil chemistry to determine whether O. revealii is a distinct lineage edaphically adapted from O. paradoxa, as has been described in the literature.
  
  
  METHODS
  We genotyped 21 populations throughout the ranges of both species using 11 microsatellite markers and three plastid regions (trnL-F, trnT-L, trnQ-rps16) for haplotype analysis. We compared these data with soil chemistry (Ca and S concentrations, indicating gypsum levels), location, and morphological identity of populations.
  
  
  RESULTS
  Soil chemistry failed to explain genetic or morphological identity in either taxon. Haplotype analysis suggests ancestral variation in the more geographically restricted O. revealii, along with regional geographic isolation. A discontinuity was identified between the morphological and genetic identity in several populations, suggesting incomplete lineage sorting and the nonfixation of identifying morphological traits.
  
  
  CONCLUSIONS
  Oreocarya revealii is unlikely to have arisen via edaphic selection, because soil chemistry of population sites, morphology of individuals, and genetic identity are not strongly correlated. The nonfixation of identifying traits is likely a result of recent divergence in this system, and the potentiality of such discrepancies should be considered when investigating recently diversified gypsum-associated groups.
authors.affiliation: Biology Department, Emory and Henry College, Emory, Virginia 24327, USA School of Biological Sciences, University of Northern Colorado, Greeley, Colorado 80639, USA gbresowar@ehc.edu.
authors.forename: Gerald E
authors.initials: GE
authors.lastname: Bresowar
authors.affiliation: School of Biological Sciences, University of Northern Colorado, Greeley, Colorado 80639, USA.
authors.forename: Mitchell E
authors.initials: ME
authors.lastname: McGlaughlin
mesh_terms: D005075:Biological Evolution; D028082:Boraginaceae / Q000033:anatomy & histology* / Q000235:genetics*; D002118:Calcium / Q000378:metabolism; D060365:Chloroplast Proteins / Q000235:genetics* / Q000378:metabolism; D003120:Colorado; D017753:Ecosystem; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D012987:Soil / Q000737:chemistry*; D013045:Species Specificity; D013455:Sulfur / Q000378:metabolism
chemical_list: D060365:Chloroplast Proteins; D012987:Soil; D013455:Sulfur; D002118:Calcium
keywords: Oreocarya paradoxa; Oreocarya revealii; edaphic selection; gypsum; incomplete lineage sorting; recent diversification