Fruit flies, like almost all other living organisms, havebuilt-in circadian rhythms that keep time even in the absence ofexternal stimuli. Several genes have been shown to be involved ininternal timekeeping, including per (period) andtim (timeless). Mutations in these two genes, andin other genes, disrupt timekeeping abilities. Interestingly, thesegenes have also been shown to be involved in other time-relatedbehavior, such as the frequency of wingbeats in male courtshipbehaviors. Individuals that carry particular mutations ofper and tim have been shown to copulate forlonger than individuals that have neither mutation. But do thesetwo mutations affect copulation time in similar ways? The followingtable summarizes some data on the duration of copulation for fliesthat carry either the tim mutation or the permutation (Beaver and Giebultowicz 2004):
| Mutation | Mean copulation duration (min) | Standard deviation of copulation duration | Sample size, n |
| per | 17.5 | 3.37 | 14 |
| tim | 19.9 | 2.47 | 17 |
b) Do the populations carrying these mutations have differentvariances in copulation duration? Enter the calculatedF-value.
c) Do the populations carrying these mutations have differentvariances in copulation duration? Finish this hypothesis test anddescribe your conclusion.
