I am combining my main interest from my undergraduate education, neuroscience, with my childhood passion, reptiles, to investigate how life history strategies, ecology, and sexual selection influence brain structure. Underlying almost all behaviour and a lot of physiology is the brain, at least in vertebrates. Animals with different life history strategies or sexual strategies must also differ in brain structure and brain function. These underlying differences are by and large a mystery as we are only starting to understand the many complex links between brain structure, brain function, and phenotype. During my PhD, I hope to shine another small light on this vast unknown.
The Evolution of Brain Structure in Lizards
I'm mapping the brains of the various species of dragon lizard of the genus Ctenophorus. These lizards, native to Central and Western Australia, may all belong to the same genus but they vary in life history, ecology, and sex in ways that make them an ideal group with which to study the associated variation in brain structure. Our first step is to create brain atlases for these lizards, and we are currently working on this in collaboration with Dr. Jeremy Ullman and Dr. Andrew Janke at the University of Queensland's Advanced Imaging Center and Dr. Timothy Stait-Gardner at the National Imaging Foundation's University of Western Sydney node.
A large part of my PhD project is based on some Ctenophorus species being sexually dichromatic and other species being monochromatic. While this seems to be evident simply by looking at pictures of males and females of various species, I quickly learned that comparing colour across lizard species is not that simple. Lizard eyes are not human eyes, and a lizard may look quite different from the perspective of another lizard compared to the perspective of a human. We are working to properly quantify sexual dichromatism across species of dragons.
Lizards Skulls and Their Holes
When I first started my PhD I was looking at potential methods for measuring brain size. In birds and mammals cranium volume is a reliable proxy for brain size and researchers travel the world measuring the cranial volumes of museum specimens by pouring lead shot into the cranium. I was looking forward to doing the same for lizards, however I quickly found that this would be impossible. The lizard's brain is not completely encased by bone as in birds and mammals, but rather their cranium is full of massive holes! It is still possible to calculate the volume of the space occupied by the brain, but how accurately does this volume reflect brain size? I will be using CT and MRI imaging to measure both cranial volume and brain volume of the same individuals so as examine this question.
Biodiversity in Tree Plantations
In 2009, under the supervision of Prof. Catherine Potvin and co-supervised by Prof. Hector Barrios, I undertook a study of biodiversity in commercial tree plantations in Panama. The goal of the project was to gain a preliminary understanding of whether commercial tree plantations could act as viable habitat for native animals. I was based at the Smithsonian Tropical Research Institute in Panama City and monitored biodiversity of select representative animal groups in Dr. Potvin's experimental tree plantation in Sardinilla for a short time over the summer. As part of the monitoring I had to learn to identify bird song down to the species, as well as know the birds by sight. As a result I blame this project for turning me into a full-on birder.
Herpetofaunal Diversity in the Congo
In 2008, under the supervision of Prof. Kate Jackson I went to Brazzaville, Republic of the Congo. The herpetofauna of this small Central African country remains virtually unknown, and Prof. Jackson is working towards uncovering the country's fantastic herpetofaunal diversity. A large part of this project is working with Congolese researchers based at the Groupe d'Etude et de Recherche sur la Diversite Biologique (GERDIB), part of Brazzaville's Universite Marien Ngouabi. In the Congo I was supervised by Congolese biologist Ange Zassi-Boulou and I collaborated with Sylvestre Boudzoumou, one of Ange's Congolese students. Together, we conducted a herpetological survey of a village 45km north of Brazzaville, and catalogued our specimens with the nascent museum at GERDIB.
The Neural Substrates of Drug Addiction
From 2005 to 2008 I worked under the supervision of Prof. Cecilia Flores at McGill University. In Prof. Flores's lab I conducted behavioural experiments on transgenic mice. I showed that these mice have abnormal behavioural responses to the locomotor and addictive properties of amphetamine and cocaine, two psychostimulants. I also worked on using immunohistochemistry to examine how the dopaminergic neurons of these mice were affected by the genetic modification. This work ultimately contributed to Dr. Flores's work examining the mechanisms underlying the role of dopamine differential vulnerability to the behavioural effects of psychostimulant drugs.