IM analysis of Panama H. melpomene and H. cydno data. The panels show approximate Bayesian posterior probability distributions for effective population size of H. melpomene (θ
), H. cydno (θ
), and the ancestor of the two species (θ
). The time since divergence of the two species (t), and the locus-specific bidirectional introgression rates are also shown (m). The three datasets analysed are the basic IM dataset (blue), and IM reduced dataset 1 (pink) and IM reduced dataset 2 (green). Analysis of the basic IM dataset is compromised by recombination within Tpi and Ci, which is assumed not to occur in the IM algorithm. Reduced datasets containing apparently non-recombined segments of the genes were analyzed to overcome this difficulty. IM reduced dataset 1 differs only from IM reduced dataset 2 in that a different, shorter, part of the Ci locus is used; the low sequence information probably explains why there is little information in the former run in the last panel (probabilities for IM dataset 1 are enhanced 10-fold in this panel only, for clarity). The curves show useful parameter estimation , except in the case of ancestral population size (θ
), the upper tail of the time of divergence (t) and the introgression for Ci for IM reduced dataset 1.