Relationship between allele ancestrality and trans-specific proximity for locus β-fibint7. Ancestrality was measured as the distance, in number of mutations, to haplotype BR25, while trans-species allele proximity was measured as the distance to the closest-related allele found in a different species. The area of each circle is proportional to the allele frequency. Alleles belonging to P. muralis (including the supposedly introgressed allele found in P. hispanica type 3) were excluded. Other putatively introgressed alleles are highlighted.
Pinho et al. BMC Evolutionary Biology 2008 8:63 doi:10.1186/1471-2148-8-63