MOLECULAR SYSTEMATICS AND EVOLUTION IN NEW-ZEALAND - APPLICATIONS TO CRYPTIC SKINK SPECIES

The polymerase chain reaction (PCR) and DNA sequencing are being used for the study of the origin and evolution of New Zealand plants and animals. Here we describe methods for rapidly obtaining DNA sequences from small amounts of fresh and preserved tissue, and apply them to the problem of resolving relationships among skinks of the Australasian genus Leiolopisma. DNA extracted from frozen tail muscle was used for the main part of the study. Part of the mitochondrial 12S ribosomal RNA gene was isolated using PCR. Direct sequencing of this 400 nucleotide region supports the separation of "L. nigriplantare" into several genetically distinct but morphologically similar species. The sequence data have also identified a potential case of hybridisation between two sympatric species in Otago, L. nigriplantare polychroma and L. maccanni. The data set supports the view that skinks have been in New Zealand very much longer than five million years. From these results we expect that application of the PCR and other techniques in molecular biology will help solve many questions about the origins and evolution of New Zealand's biota, as well as help identify unique populations for conservation.