Pleistocene refugium endemics exhibit greater allozymic diversity than widespread congeners in the genus Polygonella (Polygonaceae)

Populations of each of the 11 species of the North American angiosperm genus Polygonella (Polygonaceae) were sampled for electrophoretically detectable allozyme diversity. In contrast to expectations based on similar surveys in many other vascular plant groups, the two most widespread species of Pol...

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Bibliographic Details
Published in:American journal of botany 1995-02, Vol.82 (2), p.141-149
Main Authors: Lewis, P.O. (North Carolina State University, Raleigh, NC.), Crawford, D.J
Format: Article
Language:English
Subjects:
Alleles
BIODIVERSIDAD
BIODIVERSITE
Biodiversity
Biological taxonomies
Botany
CANADA
Conservation biology
DISTRIBUCION NATURAL
DISTRIBUTION NATURELLE
ECOLOGIA VEGETAL
Ecology and Phytogeography
Endemic species
ENZIMAS
ENZYME
ETATS UNIS
EUA
Flowers & plants
Genetic diversity
Genetic loci
Genetic variation
GENETICA
GENETIQUE
PALEONTOLOGIA
PALEONTOLOGIE
PHYTOECOLOGIE
Plants
POLYGONACEAE
Population genetics
Species diversity
TIPOS LITOLOGICOS DE SUELO
TYPE DE SOL LITHOLOGIQUE
VARIACION GENETICA
VARIATION GENETIQUE
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Summary:Populations of each of the 11 species of the North American angiosperm genus Polygonella (Polygonaceae) were sampled for electrophoretically detectable allozyme diversity. In contrast to expectations based on similar surveys in many other vascular plant groups, the two most widespread species of Polygonella showed reduced within-population gene diversity with respect to their narrowly endemic congeners. One possible explanation is that high levels of selfing in the widespread species have led to reduced population-level diversity. An alternative explanation is that large-scale migration during Pleistocene glaciations removed much of the diversity of these more northerly distributed species, while the endemics, several of which inhabit known Pleistocene refugia, were able to maintain higher levels of diversity because of population stability during the glacial cycles. If the latter explanation is correct, an important implication for conservation is that, for many genera in eastern North America, the species richest in gene diversity may be those most in danger of extirpation in the next decade, namely those species endemic to Pleistocene refugia such as the Lake Wales Ridge
ISSN:0002-9122
1537-2197
DOI:10.2307/2445522