Novelty, Plasticity and Niche Construction: The Influence of Phenotypic Variation on Evolution

It has long been recognised that phenotypic novelty poses a prima facie problem for evolutionary theory. For there is a problem in reconciling an incremental conception of evolutionary change with the evolution of qualitatively new structures, especially complex new structures (Nitecki 1990). While it is easy to see how an existing trait could be elaborated incrementally, it is much harder to see there could be (say) an incremental, and incrementally adaptive, shift from a scaled bipedal dinosaur to a feathered and flying bird. In this paper, I shall gnaw away at this problem by weaving together three new developments in evolutionary theory. Those developments, in combination, do not completely resolve the problem of novelty, but they make it more tractable.