Comparative methods for explaining adaptations.

The ways that taxonomic differences in morphology, behaviour or life history are related to each other and to differences in lifestyle have been used regularly to test ideas about the selective forces involved in their evolution. Such comparative tests have been transformed recently by using increased statistical rigour. The realization that the statistical model against which comparisons are made is a model of how evolution proceeds, forms the basis of a new generation of comparative tests that are grounded properly on phylogenetic reconstruction.