Geographic Variation for Wing Shape in Drosophila Serrata

Geographic variation in wing shape in female Drosophila serrata was examined by characterizing isofemale strains from 19 localities collected along a transect on the eastern coast of Australia. Shape variation was analyzed by Procrustes superimposition of landmark data followed by canonical variate analysis. The first extracted canonical variate showed a nonlinear association with latitude and accounted for 43% of the variance. There was a sharp increase in this variate at low latitudes as well as a gradual increase at high latitudes. These shape changes were associated with two landmarks at the edge of the wing. There was also a linear change in wing aspect. The isofemale heritability for two measures of shape was around 30%. Allometric relationships were weak both between localities and among isofemale strains within localities. The possibility that wing shape parameters are under selection independent of wing size is discussed.