I am a developmental biologist interested in how evolutionary change to genes and genomes can feed through alterations to developmental mechanisms and hence to the evolution of new animal form. A particular focus has been the evolution of the nervous system, and especially the origins of increased cell number, new cell types and augmented patterning mechanisms in the vertebrates. I also have a long-standing fascination with how the left and right sides of animal embryos become developmentally different such that internal organs can be asymmetrically distributed.