Sleep parameters and waking activity at different ages in all flies. For each age range (from 10 to 120 days; shown below each bar) mean values (+ SEM) were averaged across eleven 24-hour intervals per each fly, and then averaged across all flies. The number of flies tested at each age is indicated below each bar. Genotype (g) effects were tested across all ages (Kruskal-Wallis test, p < 0.05). Horizontal bars indicate significant age-related effects within each genotype (Friedman test followed by Wilcoxon signed-rank test, p < 0.05).