Deducing the phylogeny of New Zealand’s endemic frog genus – Leiopelma

Abstract

New Zealand’s endemic Leiopelmatid frogs represent a unique frog genus, displaying archaic morphology comparable to ancient frog fossils. Leiopelmatid frogs are one of the many species of flora and fauna endemic to New Zealand that have faced significant population and distribution declines. The conservation of these species needs to be guided by accurate genetic analysis, informing efforts to maintain the genetic diversity of these ancient frogs. As the focus of this thesis, the phylogenetic relationship between two of these Leiopelmatid frogs - Leiopelma pakeka and Leiopelma hamiltoni – will be explored through comparison of the mitochondrial genomes of these species. These genomes were generated through the combined use of Next Generation Sequencing and Sanger Sequencing technologies. The two genomes differed by over 130 bases, equating to a pairwise distance estimate of 1.1%. Comparisons between the pairwise distance estimate of these genomes with those of other Amphibia were made, with the conclusion being that a genetic divergence estimate of 1.1% was too low for the two Leiopelmatids to be rendered separate species. The divergence is closer to that of evolutionarily separate populations of the same species, guiding future conservation efforts.