Mice achieving higher BECs displayed modestly greater intakes, so we asked whether ethanol intake during the first versus the second 2-hour portions of the DID test had changed over generations. Figure 3 shows the (2 hours) intake on the first day of DID testing, and the intake on Day 2 during the first and last 2 hours of testing, after which the BEC was taken for selection. Three S11 mice were excluded from this analysis because their total consumption values on Day 2 were excessive as discussed in the Supplement 1. Generation 11 mice drank more on the first day of testing than S0 mice [F(1,319) = 41.5, p < .0001]. When we analyzed the two 2-hour periods of drinking on Day 2 across generations, there was a significant overall increase in S11 versus S0 mice when data were collapsed on time [F(1,319) = 96.8, p < .0001]. Mice of both generations drank more during the second 2-hour period on Day 2 [F(1,319) = 114.9, p < .0001], and the interaction was significant [F(1,319) = 7.2, p < .01]. Mice
