PhD Project: Recurrent ecological speciation on Amber Mountain
Starting in November 2016, the focus of my PhD has been one of the central questions in evolutionary biology: the origins of species. My project looks at ecological speciation—that is, divergence of two lineages as a result of differences in ecology. The concept of ecological speciation turns traditional views of speciation on their heads, because it can be the driver of divergence in any geographical context, be it allopatric, sympatric, or parapatric. Using ecologically distinct taxa in a common geographical context, I am investigating the principles of ecological speciation at a level that transcends individual examples. My focal taxa are three size classes of chameleon, which occupy the same geographical distribution but have distinct ecological niches. To control for micro-geography, and in particular the impacts of rivers on my study, these chameleons are complemented by one frog. The geographical system I am using for this study is Montagne d’Ambre, an isolated mountain in Madagascar’s extreme north that forms an almost ideal gradient from dry deciduous forest to montane rainforest over its altitudinal cline. Several reptile and amphibian species are known to have recently diverged or be in the process of divergence on this mountain. My project will be the most intense survey to date in Madagascar’s oldest national park, and will shed light on the distribution and composition of its communities, the origins of its native species, and the processes driving its high diversification rates.
One of my main projects is an investigation of the drivers and consequences of miniaturization in the microhylid frog subfamily Cophylinae. In this genus, we have evidence that numerous lineages have independently become diminutive in size, in some cases rivalling the smallest frogs in the world. To investigate this question, I am working together with some incredible researchers, using large micro-CT osteological and morphological datasets to understand patterns at high resolution across Madagascar’s second most diverse clade of frogs.
At any one time I am working on between five and twenty taxonomic manuscripts, ranging in scope from single species descriptions to whole genus revisions, to supraspecific taxonomy. While my main focus is on diamond frogs, I am also involved in projects working on many other cophyline microhylids, as well as Uroplatus and Geckolepis geckos, Gephyromantis frogs, Calumma chameleons, and scolecophidian snakes.