Phylogeographic genetic analysis of the alpine weta, Hemideina maori: evolution of a colour polymorphism and origins of a hybrid zone

1Department of Zoology, University of Otago, P.O. Box 56, Dunedin, New Zealand. *Author for correspondence. R02051 Received 26 November 2002; accepted 9 June 2003; online publication date 19 November 2003 Abstract Body colour is an important distinguishing feature in a New Zealand alpine weta hybrid zone and is strongly correlated with mitochondrial DNA haplotype variation. To assess the broader geographic pattern of this association, an intraspecific phylogeny was generated using mtDNA sequence. Both parsimony and likelihood analyses separated the colour morphs into two clades. One grouped the Rock and Pillar Range “yellow” haplotypes with other Central Otago populations and the other grouped the “black” Rock and Pillar haplotypes as a monophyletic group. The black body colour seen in the south of the Rock and Pillar Range appears to have evolved multiple times across the species. Application of a molecular clock estimated that the Rock and Pillar yellow and black lineages were separated approximately 2 million years ago. The Rock and Pillar yellow lineage split from other Central Otago populations approximately 1 million years later, possibly the result of sequential range contraction and expansion.