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Research

Animal coloration is influenced by a multitude of factors including the chemical and physical properties of pigments, skin, feathers and scales; the biophysics of light; the visual systems and cognitive abilities of predators, prey, mates and rivals; and the development, behaviour, life-history and ecology of animals. We need to study it from the scale of particles and molecules to communities and landscapes.

In the Stuart-Fox Lab, we primarily study the evolution and diversity of animal coloration because it provides rich insight into biological processes generating current diversity. This page provides an overview of our research areas.

Beyond colour: significance of near-infrared reflectance

Research on the optical properties of animal surfaces (scales, feathers, fur, cuticle) has focused almost exclusively on human-visible wavelengths, ignoring those greater than the limit of human vision (i.e. > 700 nm). This is a significant gap in our understanding because more than half of the energy in direct sunlight falls within those near-infrared (NIR) wavelengths, invisible to the human eye. Absorption of solar radiation in these wavelengths significantly affects energy gain and therefore thermal properties; yet, almost nothing is known of the diversity and mechanisms of near-infrared properties in animals, let alone their adaptive value. We are investigating the relationship between near-infrared reflectance and thermal environment of a range of taxa, from reptiles and birds to butterflies and beetles.
beetleNIR

Collaborators:
Ken Walker (Museum Victoria)
Adrian Dyer (RMIT)
Jair Garcia (RMIT)
Michael Kearney (The University of Melbourne)
Nick Roberts (University of Bristol)
Anne Roberts (The University of Melbourne)

Funding: Hermon Slade Foundation



 

Costs of colour: carotenoids, pteridines and the evolution of signals

Colourful red and orange signals in lizards (and many other taxa) are commonly produced by the pteridine pigment drosopterin, sometimes in combination with carotenoids. Pteridines are synthesised in situ from common purine molecules, while red carotenoids (ketocarotenoids) are predominantly enzymatically converted from dietary yellow carotenoids. Thus, drosopterin is often considered a ‘cheap substitute’ for ‘expensive’ red carotenoids. We are interested in what determines relative concentrations of pteridine and carotenoid metabolites in agamid lizards – and implications for the evolution of sexual signals.

Collaborators:frillcolour
Adrian Lutz (Metabolomics Australia)
Claire McLean (The University of Melbourne)
Katrina Rankin (The University of Melbourne)

Funding: Australian Research Council (DP150101044)



 

Colour polymorphism and speciation

Colour polymorphic species, in which multiple, genetically determined, discrete colour forms coexist within an interbreeding population, have provided many insights into evolutionary processes. Theory suggests that the processes generating and maintaining the different colour forms can promote speciation. We are studying the genomic architecture of colour polymorphism and its role in speciation between a monomorphic and polymorphic lineage of the tawny dragon.

ImageJ=1.48v

Team:
Claire McLean (PostDoc)Adnan Moussalli (Museum Victoria)
Kanchon Dasmahapatra (University of York, UK)
Caroline Dong (PhD student)

Funding: Australian Research Council (DP1092908)



 

Adaptive significance of colour change

Bearded dragon_Adam Elliott

Stemming from four years working on chameleons in South Africa, I am fascinated by the function, mechanisms and evolution of colour change, which has been an ongoing research focus in my lab. Although there are currently no active research projects in this area in my lab group, I am always open to participating in research on colour change.

Sexual selection, mating strategies, behavioural interactions

Euprymna mating_mark Norman small
An interest in visual signals necessarily entails an interest in sexual selection. We have – and continue to explore a range of topics in this general area including the dynamics of male-male contests; the evolution of sexual dimorphism; the costs of copulation; the evolution of multiple mating; the broad population fitness effects of sexual selection; and the evolution of conspicuous signals and behaviours used by females to avoid unwanted courtship and copulation attempts.

Collaborators:
Luke Holman (The University of Melbourne)
Mark Elgar (The University of Melbourne)