The developmental genetics of major evolutionary transitions: a multidisciplinary investigation of limb reduction and loss in lizards. The five-toed limb is an iconic evolutionary innovation of land vertebrates, yet has been lost repeatedly. This project will use anatomical, developmental and genetic approaches to understand how vertebrates lose their legs, whether limbs can be reacquired, and the degeneration of limb genes after they lose their function (analogous to 'vestigial organs').