How diverse are tadpoles really? With this project, we will use a range of methods, from transcriptomics to comparative phylogenetics to study the evolutionary origin and diversification of amphibian larval forms and function.
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I am interested in understanding of how parts or all of the ancestral biphasic life cycle of amphibians has been lost or modified. I use comparative phylogenetic methods to study how life history modes have evolved and how this may impact on lineage diversification. I am also interested in what may have driven the evolution of terrestrial modes of reproduction.
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Amphibian Systematics A great deal of work needs to be done to update the taxonomy and systematics of African amphibians and to gain a deeper understanding about aspects of their natural history. Recent years, perhaps fuelled by the proliferation of molecular barcoding techniques coupled with phylogenetic and coalescence species delimitation methods, have seen a surge in systematic revisions and newly described species. Together with many colleagues, I have contributed to furthering our understanding of species, their distributions, biogeography and natural history for a number of African amphibians.
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Developmental and Phenotypic Plasticity An organism’s phenotype is the product of its genes and its environment. This plasticity is considered adaptive when changes in phenotype in response to a specific environmental condition improve the organism’s fitness. Adaptive developmental plasticity is therefore an interesting mechanism for coping with environmental heterogeneity. I am interested in understanding the molecular mechanism that underlie the regulation of plastic phenotypes. We apply genomic techniques including RNAseq and ATACseq to study the generation of environmentally sensitive phenotypes.
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An organism’s capacity to track and resemble its background (‘background matching’) is an important cryptic mechanism in the animal kingdom. Some species have evolved facultative colour change, a remarkable form of phenotypic plasticity, to match temporally or spatially heterogeneous backgrounds. Here, we quantify the capacity of such facultative changes in pigmentation in Western Spadefoot tadpoles (Pelobates cultripes), by manipulating the background colour of aquaria. We find that tadpoles of this species are capable of detecting and responding to even minor changes in background brightness by adjusting the pigmentation content in their skin.
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Genome Size Evolution Genomes of different organisms vary hugely in size. Most of this difference is not linked to organism complexity, but instead, in the amount of non-coding DNA. Whether or not life history traits affect the evolution of the physical size of genomes is unclear. On a cellular level, large genomes impose physiological rate limits and processes like cell proliferation and differentiation are significantly slower. This is particularly important for amphibians, which have some of the largest genomes of all known vertebrates and many undergo complex life history transitions that involve both rapid growth as well as cell and tissue differentiation.
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