Figure 6. RDA of all collections in Columbia River basin to model the degree to which the variation in environmental variables explains the variation in allele frequencies for candidate markers for all collections in the greb1L haplotype block (2,3,6). The populations are represented by text and colored black or red in accordance with their lineage determined by DAPC in adegenet. The arrows spatially denote a significant influence of environmental variables and the length of the arrow indicates the extent of the effect. Environmental variables retained were migration distance, minimum temperature warmest month, August water temperature over a 20-year average, annual mean temperature, isothermality, and annual precipitation.