offered water, the HDID-1 mice were shown to be intoxicated in the balance beam test. The heritability estimated from the realized response to selection after 11 selected generations was h2 = 0.09, and the relatively slow rate of response suggests that the trait is multigenic and perhaps highly polygenic (influenced by genes that each have a small effect on the phenotype). Mice achieved higher BECs than the HS/Npt population from which they were selected—this stock serves as the control line, as this selection was not bidirectional.
