As above, I think a more appropriate analysis would be to ask if the sizes of the differences between the haplotypes is the same in the transgenics and the accessions (i.e., is the slope of the graph different from 1?). A more straightforward answer to the question of how much variation in FLMB is explained by these haplotypes is simply to report the R2 for the analysis shown in Figure 8—figure supplement 1D.