Evidence for ancestral lineage sorting with recombination. The plots on the left indicate, across the length of the locus, the posterior probability of each of the topologies shown on the right. (a) mitch supports two different tree topologies, A and B, for the relationship between D. lutescens, D. eugracilis, and the melanogaster subgroup. (b) seq211 supports all three possible topologies in the melanogaster subgroup.