Jr. Jaeger et al., Rediscovering Rana onca: Evidence for phylogenetically distinct leopard frogs from the border region of Nevada, Utah, and Arizona, COPEIA, (2), 2001, pp. 339-354
Remnant populations of leopard frogs within the Virgin River drainage and a
djacent portions of the Colorado River (Black Canyon) in northwestern Arizo
na and southern Nevada either represent the reportedly extinct taxon Rana a
ca or northern, disjunct Rana yavapaiensis. To determine the evolutionary d
istinctiveness of these leopard frogs, we evaluated mitochondrial DNA (mtDN
A) restriction site variation (RFLP), mtDNA control region sequences, rando
mly amplified polymorphic DNA (RAPD) markers, and morphological characters,
Individuals from the Virgin River drainage and Black Canyon represented a
single RFLP haplotype and were identical for nucleotides along a portion of
control region sequence. Evaluations of RAPD data demonstrated high levels
of similarity among individuals and populations from this region. Leopard
frogs from the virgin River drainage and Black Canyon differed from R. yava
paiensis from west-central Arizona and northern Mexico in maximum parsimony
and distance analyses of RFLP and control region sequence data and in maxi
mum-likelihood analysis of the sequence data. Multidimensional scaling of R
APD data provided a similar and congruent indication of this separation. An
alysis of principal component scores demonstrated significant morphological
differentiation between leopard frog specimens from the Virgin River drain
age and R yavapaiensis. Parallel patterns of divergence observed in the mtD
NA, RAPD, and morphological analyses indicate that leopard frogs from the V
irgin River drainage and adjacent portions of the Colorado River are phylog
enetically distinct. These leopard frogs should be recognized as a lineage
separate from southern populations of R. yavapaiensis and classified as the
species R, onca.