Figure 4

A hypothetical monophyletic tree with three distinct clades (1), (2) and (3), where the A allele appears to have arisen in the extant species more than once. This abnormal inheritance is due to either a homoplastic double mutation, a hybridisation event by two members of clade 2 with a member of clade 1 or lineage sorting has occurred on a homologous A/C polymorphism that arose in the most recent common ancestor (MRCA) of clades 1 and 2.