School of Animal Biology

Esther Levy

Thesis

Genetic Variation and Population Viability in the Ornate Dragon Lizard, Ctenophorus ornatus

Summary

Natural populations frequently become small and isolated as a result of habitat loss and alteration. A corresponding loss of genetic variation is expected to significantly reduce population evolutionary potential and ultimately lead to extinction.

My project focuses on genetic variation in small and isolated populations of the ornate dragon, Ctenophorus ornatus; concentrating on how it can be lost and the long-term consequences such a reduction. In particular, my study aims to:

1. Provide an analysis of the genetic structure of this species.
2. Assess the impact of land clearing on gene flow and genetic variation.
3. Explore a consequence of reduced genetic variation by examining the relationship between genetic variation and parasite load.
4. Resolve which long-term consequence of decreased genetic variation, mutational meltdown, or purging by inbreeding, occurs in small populations by using a novel method.

Why my research is important

A common problem in genetic studies of small isolated populations is the lack of replication in natural populations examined. Threatened species typically persist in only a few small isolated populations, yet to indentify common trends it is necessary to compare many such populations. The ornate dragon provides an ideal opportunity to create a powerful test of the causes and long-term outcomes of reduced genetic variation in small isolated populations. There are numerous populations, in a range of sizes, of this endemic reptile scattered throughout the West Australian wheatbelt region and offshore islands. Therefore, this project will provide valuable information about the genetic health of small isolated populations of this lizard and can be used to improve current management practices for dealing with similar populations in other species.

Specifically, the ornate dragon is relatively unstudied in its natural environment and this research will provide information about the ecology and conservation status of this native West Australian reptile.

Funding

• Australian Postgraduate Award
• School of Animal Biology