High degree of population subdivision in a widespread amphibian.
In general, amphibians are known to exhibit a higher degree of population subdivision than any other major animal taxa, but large-scale population genetic surveys of widely distributed species are still scarce, especially in the Eurasian continent. Using microsatellite markers and mitochondrial DNA sequences, we investigated the large-scale population genetic structure of the common frog (Rana temporaria)--one of the most widespread amphibians of the Palearctic region. Analyses of cytochrome b sequences revealed evidence for two distinct lineages inhabiting western and eastern parts of Europe. The separation of these lineages c. 700,000 years ago may have been induced by the onset of the Middle Pleistocene continental glaciations. Analyses of the variability of microsatellite loci within each of the clades revealed evidence for evolution of a high degree of population subdivision (FST approximately 0.23) even in northern Fennoscandia, colonized less than 10,000 years ago. The high level of substructuring is puzzling in the face of an apparently high dispersal capacity, as evidenced by the rather rapid recolonization of northern Europe. This suggests that processes other than restricted dispersal capacity need to be explored as explanations for the high degree of population subdivision in amphibians. The colonization of northern Europe has been accompanied by loss of genetic variability as evidenced by decreasing levels of intrapopulational genetic variability in microsatellite loci from south to north across Europe.
Ecological Genetics Research Unit, Department of Biological and Environmental Sciences, PO Box 65, FI-00014 University of Helsinki, Finland. jukka.palo@helsinki.fi
Jukka U
JU
Palo
Dirk S
DS
Schmeller
Anssi
A
Laurila
Craig R
CR
Primmer
Sergius L
SL
Kuzmin
Juha
J
Merilä
D000818:Animals; D001483:Base Sequence; D016000:Cluster Analysis; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics; D005060:Europe; D005787:Gene Frequency; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D016013:Likelihood Functions; D018895:Microsatellite Repeats / Q000235:genetics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D011157:Population Dynamics; D011896:Rana temporaria / Q000235:genetics* / Q000502:physiology; D017422:Sequence Analysis, DNA
D017931:DNA Primers; D004272:DNA, Mitochondrial