ABSTRACT
Scientists interested in evolutionary patterns develop hypotheses about the history of a particular group of animals on the basis of some source of information (e.g., morphological features of the skeleton), and then test them against a new database derived independently (e.g., molecular evidence). Gaps are filled with hypotheses and these are tested against new information as it arises (e.g., new fossils, new analytical techniques). These studies provide an important frame of reference for an understanding of behavioral evolution, the main concern of comparative psychologists.
