Our group takes an integrative approach to determine the mechanisms central to the origin and maintenance of the spectacular species diversity we see in the world today.
The core questions we seek to address are: How do sources of selection interact to shape the course of evolution and the generation of biodiversity? & Why do organisms follow certain evolutionary trajectories when many are possible? To tackle these questions we integrate population genomics, field collections and experimental estimates of natural selection. Much of our work falls into two streams: visual ecology or eco-evolutionary genomics.
Vision is a particularly interesting trait to study because it has a well characterized genetic basis, and is likely under strong natural and sexual selection in many systems. We are interested in understanding how visual systems evolve in novel spectral environments. Previously our work has shown that substantial evolution of the visual system can occur on very short time scales and that adaptation of the visual system involves changes in opsin gene sequence, repertoire and expression. We are now working towards direct estimates of selection on traits relevant to vision.
Biotic agents of natural selection (e.g. predators, competitors, symbiants) are thought to play an important role in diversification. However, we have little idea about the imposed selective landscapes or evolutionary responses to these agents. We use field studies and manipulative experiments to disentangle the contributions of such biotic agents to observed patterns of divergence. Our experimental work has revealed the importance of differential predation in driving phenotypic and genomic diversification. Our fieldwork has indicated that the gut-microbiome may be involved in an eco-evolutionary response to resource competition.
To further elucidate the genetic and ecological factors that influence evolutionary trajectories we use large scale population genomic analyses. So far we have examined whether pleiotropy is a source of evolutionary constraint that underlies the predictability of evolutionary responses and we are working on investigating the contribution of copy number variation.