The future of evo-devo: model systems and evolutionary theory.

There has been a recent trend in evolutionary developmental biology (evo-devo) towards using increasing numbers of model species. I argue that, to understand phenotypic change and novelty, researchers who investigate evo-devo in animals should choose a limited number of model organisms in which to develop a sophisticated methodological tool kit for functional investigations. Furthermore, a synthesis of evo-devo with population genetics and evolutionary ecology is needed to meet future challenges.