Figure 6. Signals of selection in UCSD juncos.Redundancy analysis (RDA) between 132,343 SNP response variables and
four explanatory variables corresponding to environmental factors (mean
temperature of the warmest quarter, temperature seasonality, greenness,
and elevation) for Oregon junco forms. Points represent the projection
of individual genotypes on the first two RDA axes. Marker colors
correspond to those on the range map in Fig. 1. The explanatory
variables are shown within the space defined by RDA1 and RDA2 by labeled
vectors, and their contribution to each axis is represented by the
length of their orthogonal projections over the scale bars along the x
and y axes. Vector arrows indicate the direction of the gradient of
variation for the corresponding environmental parameter. The loading
score of each sample point on each explanatory variable can be obtained
by an orthogonal projection on the corresponding plotted vector.