##Week1_Homework

My project is focused on the changes to genetic architecture that contribute to phenotypic changes, specifically changes to shape and size, in the Drosophila wing. Flies from high altitude populations tend to have larger wings, while flies from low altitude populations have smaller wings (there are also distinct shape changes between the two populations). Six nearly isogenic lines (three from each high and low populations) were selected and crossed for 20 generations. From these progeny, I will select the most "high-altitude" and "low-altitude" like for shape and size and genotype these animals with the hope that we can identify specific polymorphisms associated with the "high-altitude" phenotype.

The data set I currently have to work with is the shape and size data for the 6 lines used in this crossing scheme as well as a number of other (exact number TBD) lines used in the lab. The data from the other lines will be obtained from anohter grad student in the lab (Maria). Because there is a high degree of variation within the low-altitude and high-altitude populations (almost as much as exists between populations), we want to ask if these 6 selected lines are actually representative of the variations observed within populations. For each line there are observations of 20-60 individuals. Each observation consists for a measure of size, coordinates for 12 landmarks (2 degrees of freedom) and 36 of semi-landmarks (1 degree of freedom each). With these data, I want to ask if the 3 selected lines within each population are distinct from one another for both shape and size and if these are representative of the variation observed within the population. The data is made more complicated because lines could have been raised under diffrent environmental conditions and the shape data was collected from different students, introducing more noise into the data set.