Does testosterone produce duds or studs? A performance-based examination of the Immunocompetence Handicap Hypothesis. The evolutionary persistence of testosterone (T) as a vertebrate reproductive hormone is viewed as a double-edged sword. On the one hand T secretion is required for development and expression of appropriate reproductive functions. On the other hand T is known to suppress immune functions and is thus considered a liability to male health. We are examining an alternate hypothesis: ....Does testosterone produce duds or studs? A performance-based examination of the Immunocompetence Handicap Hypothesis. The evolutionary persistence of testosterone (T) as a vertebrate reproductive hormone is viewed as a double-edged sword. On the one hand T secretion is required for development and expression of appropriate reproductive functions. On the other hand T is known to suppress immune functions and is thus considered a liability to male health. We are examining an alternate hypothesis: that T-induced immunosuppression benefits breeding males by protecting their physical performance levels during immune challenge. We will examine this hypothesis by quantifying the interactive effects of T and immune challenge on the aerobic capacity of male birds.Read moreRead less
Evolution of viviparity in reptiles: the fundamental role of junctional complexes. This project utilises unique Australian reptile fauna to understand global questions in fundamental biology. We will discover basic biological information on native species, which will be important in future conservation of Australian ecosystems and animals and ultimately in helping to maintain Australia's biodiversity. The project also provides training opportunities for graduate and undergraduate students in ....Evolution of viviparity in reptiles: the fundamental role of junctional complexes. This project utilises unique Australian reptile fauna to understand global questions in fundamental biology. We will discover basic biological information on native species, which will be important in future conservation of Australian ecosystems and animals and ultimately in helping to maintain Australia's biodiversity. The project also provides training opportunities for graduate and undergraduate students in several different research methods that are widely applicable in the more general Australian workforce. Because the research work is genuinely cross-disciplinary research, its findings are applicable to both biological and medically oriented technologies.Read moreRead less
Uterodomes and the evolution of viviparity. We will test the hypothesis that uterodomes, which are cell structures unique to the early pregnant uterus in mammals, and the cellular changes accompanying their development, are essential to the evolution of viviparity in amniotes. The proposal stems from our recent discovery that uterodomes develop in the uteri of viviparous lizards as well as in mammals, suggesting key commonalities at the cellular level in the evolution of live birth across amnio ....Uterodomes and the evolution of viviparity. We will test the hypothesis that uterodomes, which are cell structures unique to the early pregnant uterus in mammals, and the cellular changes accompanying their development, are essential to the evolution of viviparity in amniotes. The proposal stems from our recent discovery that uterodomes develop in the uteri of viviparous lizards as well as in mammals, suggesting key commonalities at the cellular level in the evolution of live birth across amniote vertebrates. We will take advantage of the unique combination of placental types among Australian lizards, including a species with both oviparous and viviparous populations.Read moreRead less
Evolution of sound localisation in vertebrates: head size, sound frequency and neural phase-locking. Hearing is our most important sense for interpersonal communication, yet we have a fragmentary understanding of the basic mechanisms involved in normal hearing. This project addresses the question of how sound location is represented in the brain through the processing of minute time difference with which sounds reach the two ears. The outcome will ultimately enable us to infer how the human brai ....Evolution of sound localisation in vertebrates: head size, sound frequency and neural phase-locking. Hearing is our most important sense for interpersonal communication, yet we have a fragmentary understanding of the basic mechanisms involved in normal hearing. This project addresses the question of how sound location is represented in the brain through the processing of minute time difference with which sounds reach the two ears. The outcome will ultimately enable us to infer how the human brain localises sound, with practical applications for improved virtual auditory realities and hearing aids.Read moreRead less