Figure 1.

Cladograms as described in the text for the four species groups used in this study – a) the melanogaster species group; b) the virilis species group; c) the picture wing species group and d) the repleta species group. Numbers above branches indicate the bootstrap values for the nodes to the right of the number. The trees on the left are for DNA sequences only and the trees on the right are for chromosomal inversion data. < indicates a bootstrap value less than 50%.