J. Rafinski et W. Babik, Genetic differentiation among northern and southern populations of the moor frog Rana arvalis Nilsson in central Europe, HEREDITY, 84(5), 2000, pp. 610-618
Starch gel electrophoresis and morphometric characters were used to assess
the geographical variation between 14 populations of the moor frog, Rana ar
valis, from northern and southern areas in Central Europe. Six of the 13 sc
reened allozyme loci were polymorphic (95% criterion). No fixed differences
in allele composition between the two regions were found. Some of the alle
les were region specific. Genetic variability as measured by expected heter
ozygosity ((H) over bar(e)) and number of alleles per locus was significant
ly lower in the southern samples than in northern ones ((H) over bar(e) = 0
.104 and (H) over bar(e) = 0.156, alleles/locus = 1.6 and 1.8 respectively)
. This is interpreted as a consequence of the different past history of the
se two groups during the Pleistocene. Population subdivision, as measured b
y F-ST, was substantial (0.124 and 0.078 for the southern and northern grou
p, respectively); 59.9% of the between-locality variation is attributed to
this division into two geographical groups. Isolation-by-distance was detec
ted by significant negative correlation between the estimate of gene flow (
log (M) over cap) and log(geographical distance) only for the southern popu
lation groups. This indicates that the northern populations have recently r
ecolonized their contemporary distribution area. The mean genetic distance
between the northern and southern group of populations was D-N = 0.062. Des
pite the relatively low genetic distance between them, the two population g
roups form two distinct clusters in the maximum likelihood (ML) tree. Discr
iminant analysis on 11 size adjusted body measurements showed considerable
overlap between populations from different geographical areas. An isolated
Romanian Reci population which genetically belongs to the southern group of
populations was morphologically situated in an intermediate position betwe
en northern and other southern populations.