Genetically depauperate but widespread: the case of an emblematic mediterranean pine
Langue
en
Article de revue
Ce document a été publié dans
Evolution - International Journal of Organic Evolution. 2008, vol. 62, n° 3, p. 680-688
Wiley
Résumé en anglais
Genetic variation is generally considered a prerequisite for adaptation to new environmental conditions. Thus the discovery of genetically depauperate but geographically widespread species is unexpected. We used 12 paternally ...Lire la suite >
Genetic variation is generally considered a prerequisite for adaptation to new environmental conditions. Thus the discovery of genetically depauperate but geographically widespread species is unexpected. We used 12 paternally inherited chloroplast microsatellites to estimate population genetic variation across the full range of an emblematic circum-Mediterranean conifer, stone pine (Pinus pinea L.). The same chloroplast DNA haplotype is fixed in nearly all of the 34 investigated populations. Such a low level of variation is consistent with a previous report of very low levels of diversity at nuclear loci in this species. Stone pine appears to have passed through a severe and prolonged demographic bottleneck, followed by subsequent natural- and human-mediated dispersal across the Mediterranean Basin. No other abundant and widespread plant species has as little genetic diversity as P. pinea at both chloroplast and nuclear markers. However, the species harbors a nonnegligible amount of variation at adaptive traits. Thus a causal relationship between genetic diversity, as measured by marker loci, and the evolutionary precariousness of a species, cannot be taken for granted< Réduire
Mots clés en anglais
CHLOROPLAST MICROSATELLITES
CONSERVATION GENETICS
DIVERSITY DEPLETION
HUMAN IMPACT
GENETIC DIVERSITY
PINUS PINEA
PIN PARASOL
Origine
Importé de halUnités de recherche