Sex in Dragons -- Ecological drivers of transitions between GSD and TSD Posted in Pogona Research on May 09, 2017
The Institute for Applied Ecology is seeking two PhD students with interests in population genetics and reptile ecology/physiology to investigate the field-based mechanisms of sex reversal in the dragon lizard, Pogona vitticeps. Project Description Reptiles exhibit an astonishing diversity in the means by which sex is determined early in development, genetic systems with male or female heterogamety, systems where temperature determines sex, and systems where environment and genotype interact to determine sex. The dragon lizard has female heterogamety, as in birds, yet temperature can over-ride this system to determine sex. This system is ideal for examining the interaction of genetic and environmental influences on sexual phenotype under natural conditions. The projects are supported by an ARC Discovery Grant awarded to Team Pogona led by Professor Arthur Georges, but involving a broad team spanning a number of leading researchers and institutions. The successful candidates will be based in Canberra. The first PhD candidate will seek to determine (a) how the frequency of sex reversal varies geographically; (b) if that variation correlates with micro-climate; (c) whether transitions between GSD and TSD occur in nature following the recent discovery that sex reversal occurs in nature; (d) if there is evidence of retention of cryptic sex chromosomes in populations where temperature is the primary driver of sex; and (e) at what scale does genetic variation structure across the landscape. This project will require significant time in the field collection collecting tissue samples throughout the range of Pogona vitticeps. The successful candidate will work closely with supervisors Prof. Stephen Sarre, Dr Clare Holleley and Arthur Georges. The second PhD candidate will focus on thermal biology of adults and nests, differential behavior of sex reversed females, normal females and males, differential fecundity, movements and home range using radio-telemetry. There will also be an opportunity to study the role of water balance in governing movement patterns and periods of inactivity. Demonstrating sex reversal in natural nests, and obtaining estimates of the relative fitness of normal and sex reversed females in the wild will be target outcomes, to complement definitive results already established in the laboratory. This project will require extended periods based in western Queensland at a field site near Eulo, where sex reversal has been detected. The successful candidate will work closely with supervisors Profs Stephen Sarre, Brian Green and Arthur Georges The Ideal Candidate The ideal candidate for the first PhD opportunity will possess experience in population genetics/genomics and spatial population modelling. Knowledge of NGS approaches and analyses is desirable, and past work using the abovementioned techniques and an interest in sex determination would be valuable. The ideal candidate for the second PhD opportunity will possess substantial experience in field based research including radio-telemetry, preferably on reptiles, and a good knowledge of physiological ecology. Both candidates will be expected to be self-motivated and well-organized, with the capacity to work in remote locations (including a driver’s licence) and the broad skill set necessary for the successful completion of a research project. They will be collegial and able to work alongside a wide variety of people in the field and in multi-function teams. They will have a strong commitment to excellence in research and scholarship. Stipend Financial support for domestic and international students is expected to be available for a high achieving student through the mid-year scholarship round at the University of Canberra. These scholarships are highly competitive. To be competitive, candidates should have a first class honours degree or equivalent in a relevant area and other evidence of research potential (such as publication). Eligibility The University of Canberra scholarships are open to all nationalities. However, overseas candidates for whom English is not a first language must secure an IELTS score of 6.5 and have no individual score falling below 6.0 to satisfy our English language requirements. How to Apply Interested applicants are encouraged to make informal enquiries to Professor Stephen Sarre. Please send your curriculum vitae, a sample of your written scientific work, and the names of two referees with a covering letter to: Professor Stephen Sarre [stephen.sa...@canberra.edu.au] on or before June 10, 2017. For further information on the Pogona project and publications, visit http://iae.canberra.edu.au/georges/projects/
