Environmental associations of the NR1D1 cTNR
We retained the first four principal components for our ecological
association RDA analyses, which explained ~86% of the
variation in our environmental variable dataset (Table 3). According to
the eigenvectors, the first principal component was most highly
influenced by precipitation variables (precipitation of the wettest
quarter, precipitation of the driest quarter and average snow cover;
Table 4). Our second component was largely influenced by habitat
(proportion of suitable and unsuitable lynx habitat; Table 4). The third
component was influenced by both temperature (mean temperature of the
warmest quarter) and average snow depth (Table 4). Our fourth component
was explained by a combination of precipitation (precipitation of the
wettest and driest quarters, and average snow depth) and temperature
(mean temperature of the warmest quarter; Table 4).
The partial RDA models describing environmental and spatial effects onNR1D1 genetic variation (controlling for neutral genetic
structure) were only significant in the eastern Canada lynx data subset
(p=0.001 and 0.008 for space and environment, respectively; Table 5). In
this data subset, the total explainable variation was 0.2128, of which
the effects of purely neutral genetic structure accounted for the
largest proportion of variance (63.20% of total explainable variation,
p=0.001), followed by the joint (collinear) effects of neutral
structure, environmental and spatial data (28.81% of total explainable
variation, p=0.001), with purely environmental and spatial data
contributing much smaller, but still significant proportions of
variation (4.93% and 3.05% total explainable variation in space and
environment, respectively; Table 5). In the full dataset, only the full
model and partial RDA model describing the effects of neutral genetic
structure (controlling for environmental & spatial data) were
significant (p=0.001; Table 5). Here, the total proportion of
explainable variation was lower (0.1592), and largely comprised of the
effects of purely neutral structure (71.73%), and the joint effects of
neutral structure and environment/space (26.01%), with
environmental/spatial effects contributing small, insignificant amounts
to explained variation (0.19% and 2.07% for space and environment,
respectively; Table 5). No models in the western data subset were
significant suggesting that neither neutral genetic structure nor
environmental or spatial variation explain genetic variation at theNR1D1 locus in this dataset (Table 5).