Historical perspectives in ecology and evolutionary biology: the use of phylogenetic comparative analyses

Hypotheses about the adaptive significance of a trait have long been tested by making comparisons among species. Many recent studies emphasized that conclusions about the origin and maintenance of adaptations as well as the underlying selective processes derived from comparative tests may be strengthened with the inclusion of a phylogenetic hypothesis. Major advances in the comparative approach have therefore occurred with the coincident developments in numerical methods available for phylogenetic inference. In this review, we outline the advantages and possible disadvantages of adopting an historical approach in ecological and evolutionary studies. We begin by discussing the need for including informatipn on the phyletic relationships among taxa in ecological and evolutionary analyses. Next we describe how an historical approach not only refines the definition and recognition of adaptations, but also provides an objective definition of "phylogenetic constraints." Because conceptual and analytical advances in comparative methods are occurring quite rapidly, we provide a brief summary of the goals,