FIGURE CAPTIONS
Fig 1. Bayesian tree based on 107 unique haplotypes in the combined
cytochrome b and control region dataset (1652 bp) calculated in BEAST.
Black dots indicate nodes with a posterior probability (BPP) of 1.0.
Three lineages (East, Midwest, and Southwest) received high support
whereas Central did not (BPP = 0.652). Time since most recent common
ancestor (TMRCA) analysis estimated the oldest split as Southwest vs.
the other lineages. Each TMRCA estimate is positioned above its
corresponding node along with its 95% confidence interval.
Fig 2. Geographic distribution (A), principal coordinates analysis
(PCoA, B), and median joining haplotype network (C) for the combined
cytochrome b and control region (1652 bp, n = 118). The Central (light
blue, squares), East (dark blue, diamonds), Midwest (purple, circles),
and Southwest (orange, triangles) showed differentiation in both the
PCoA and haplotype network with Central in the middle of the three other
lineages. The first axis of the PCoA (variance explained = 25.78%)
separated Southwest and Central (negative values) from Midwest and East
(positive values) whereas the second axis (variance explained = 21.71%)
separated East and Midwest. Correspondingly, the median joining
haplotype network exhibited four main groups separated by a minimum of
15 mutational steps. The most divergent groups were Southwest and
Midwest (52 total mutational steps).
Fig 3. Results of the reduced control region dataset (636 bp) in 336
white-footed mice. Greater geographic sampling clarified the
distribution of each lineage (A) where Central (light blue, squares)
occurred in the southern Midwest and parts of the southwest, East (dark
blue, diamonds) in most of the eastern United States and Canada, Midwest
in the upper Midwest (purple, circles), and Southwest within Texas,
Mexico, Oklahoma, and New Mexico (orange, triangles). Despite decreased
power in the reduced dataset, all four lineages were apparent in the
principal coordinate analysis (PCoA; B), and median joining haplotype
network (C). Axis 1 of the PCoA separated Central, Midwest, and
Southwest (negative values) from East (positive values; variance
explained = 29.67%). The second axis revealed differentiation between
Midwest, Central, and Southwest (variance explained = 13.42%). In the
haplotype network, all lineages were separated by at least 6 mutational
steps, and the most divergent groups were Southwest and East (17 total
mutation steps).