Panel A shows a minimum spanning network indicating the number of nucleotide differences detected among koala mtDNA hypervariable region haplotypes. Identical sequences were grouped together as a single unique haplotype. Unshaded nodes indicate haplotype sequences found in both museum and modern samples. Shaded nodes represent sequences detected only in modern samples. The position of the changes relative to the koala reference mtDNA genome (AJ005852) is indicated for each variant site by an arrow e.g. K5 differs from K6 by an A-G change at position 672 where K5 has the reference base adenine and K6 has a change to guanine at that position. Numbers of samples in which each haplotype was detected are indicated for modern (“Mod”) and museum (“Mus”) samples. For haplotype K3 (asterisk), identified by Fowler et al. , the number of modern koalas carrying the haplotype was not reported. The geographic distribution of each haplotype (northern or southern Australia, or both) is indicated. Panel B shows the approximate current range of koalas (shaded) in Australia. The historical haplotypes identified are indicated inside the parentheses. The map image was adapted from map images provided by the Australian Government, www.ga.gov.au.