Circular phase analysis of luciferase expression in isolated body parts. The left column shows phase comparisons for BG-luc; cry+ (plotted with asterisk) vs tim-luc; cry+ (plotted with open circles). The right column shows BG-luc; cry+ (plotted as asterisk) vs. BG-luc; cryb (plotted as open circles). All of the data shown here were collected in a light-dark cycle (LD 12:12). The time of lights on is indicated as 0 h on the circle. On these plots time moves forward in a counter-clockwise direction. Phase estimates for each rhythmic specimen are plotted just outside the unit circle and a mean vector summarizes the phase of the group with the mean direction indicating the time and the magnitude of the vector indicating the dispersion (variability) of the individual estimates (see Materials and Methods and [27, 32]). The Watson-Williams-Stevens test returns an F-statistic that is used to evaluate whether the vectors are significantly different from one another. Rayleigh's test [27, 32] shows each vector is significantly different (p < 0.05) from the null vector (random distribution) with the exception of the BG-luc; cryb vectors shown on the right for heads and bodies in b and c respectively. Beneath each circular plot the difference in hours is given, followed by the mean time for each vector with the number of specimens, n, in brackets, and a p-value for the comparison, a.) comparisons for isolated antennal pairs, b.) isolated heads, c.) isolated bodies. Number of rhythmic samples for each group are given in Table 1 and Table 2. This analysis is continued in Figure 8.