Fig. 1

Responses to artificial selection of nocturnal/diurnal locomotor activity. a. Distribution of ND ratios of males from the starting population (C₀, n = 176). The insets show actogram examples of diurnal (top) and nocturnal flies (bottom). Grey and yellow shading represent night and day, respectively. b. Average ND ratios of males from selected populations per cycle of selection. The black solid line is the nocturnal selection, while the dashed line is the diurnal selection. Data points correspond to average ND ratios ± standard deviation (n = 104–316). Grey points at the 4th and 10th cycle of selection correspond to ND ratios for the unselected control population (n = 19–78). The ND ratio of the original population is shown at C0. c. Correlation between mid-parent (n = 105) and mid-progeny (n = 105). Correlation coefficients and p values are reported below the regression eq. d. Correlation between mothers (n = 85) and daughters (n = 85)