Phylogenetic methodologies for studying specialization

Although the concept of specialization has played a central role in the development of ecological and evolutionary theory, important questions about specialization remain largely unanswered. We argue that the traditional division of specialization into evolutionary and ecological factors may be less useful than considering specialization as three components, which may not be mutually exclusive: ecological, behavioral, and functional. Many ecologists assume that these different aspects of specialization are necessarily correlated. However, this assumption has rarely been tested, but could be examined by using a phylogenetic approach. We argue that (1) ecologists should measure these different aspects of specialization within their respective organisms by placing measures of specialization on a standardized scale, and (2) should employ phylogenetic approaches for understanding how these components evolve. We argue that this approach will provide a more coordinated understanding of how specialization evolves.