Ecotype diversification and phenotypic convergence
Animals from different clades but subject to similar environments often evolve similar body shapes and physiological adaptations due to convergent evolution. Australia's biome diversity, isolation, and aridification history provide excellent opportunities for comparative analyses on broad-scale macroevolutionary patterns.
Adaptation to different ecological niches plays a crucial role in morphological evolution, boosting phenotypic diversity within a clade. Despite phylogenetic conservatism, morphological adaptation to repeatedly emerging new environments can erase the signature of ancestral morphotypes, resulting in phenotypic diversification and convergence both within and between diverse clades.
For more information see these articles:
Vidal-Garcia et al. (2014) Journal of Evolutionary Biology
Vidal-Garcia & Keogh (2015) Journal of Evolutionary Biology
Vidal-Garcia & Keogh (2017) Ecology & Evolution
(picture: Marion Anstis)
Morphological evolution of Australian frogs
Using an x-ray micro CT scanner, I gather 3-Dimensional data from Australian frogs. I am interested in identifying the processes that drive morphological evolution, especially when accounting for shape diversification across multiple structures.
For example, are evolutionary patterns and the amount and direction of morphological changes similar in skulls and limbs? And what is driving their morphological diversity? What role has diet, locomotion, burrowing behavior, and ecology played in the morphological diversity we see in each structure?
For more information see:
Vidal-Garcia & Keogh (2017) BMC Evol. Biol.
Frogs are well known for their impressive jumping abilities. However, the diversity of locomotive modes exhibited by these amphibians is similarly astonishing. I am examining the locomotive performance of a large number of Australian frog species. I am also very interested in the contributions of morphological, ecological, and phylogenetic correlates to the jumping performance of each frog species.
I am conducting jumping kinematics trials in collaboration with Conrad Hoskin (James Cook University), Dale Roberts (University of Western Australia), and Trevor Murray (Australian National University).
Rocket frog (Litoria nasuta) jumping
Check out other slow-motion videos of an arboreal frog jumping and a fossorial frog hopping here.
Articulated structures are a critical component of overall phenotypic diversity, but 3-Dimensional data gathered from these structures is difficult to incorporate in to modern shape analyses, because of the complexities associated with jointly quantifying 3D shape in multiple structures. ShapeRotator is an R tool, based on a simple geometric rigid rotation approach that completely removes the effect of random translation and rotations, enabling the morphological analysis of 3D articulated structures. This method is based on Cartesian coordinates in 3D space so it can be applied to any morphometric problem that also uses 3D coordinates. It can be applied to single-point articulations (e.g. humerus and radioulna in a frog arm) and double-point articulations (e.g. skull and mandible).
For more information see:
Vidal-Garcia et al. (2018) Ecology & Evolution
And check out the ShapeRotator Wiki
Morphological evolution of lizard brains with Daniel Hoops (McGill University, Montreal, Canada).
For more information visit Dan Hoops' website and see:
Hoops et. al. (2017) Journal of Evolutionary Biology
Hoops et. al. (2017) Brains, Behaviour and Evolution.
Honours student - Sarah Stock
Sarah is working on quantifying the correlates of extinction risk in Australian frogs. Co-supervised with Scott Keogh.