ABSTRACT

The term com parative m ethod refers to the making of explicit comparisons of observable traits among different species. Although many variants of the comparative method exist, at heart comparisons are used mainly to identify, on the one hand, similarities of traits due to common evolutionary ancestry and, on the other, similarities due to convergent adapta­ tions. In its strongest manifestation, the com­ parison is among species whose evolutionary relationships are already established and whose life-history patterns have been well character­ ized. The comparative method in biology can be applied to any observable trait of a plant or animal, including those of morphology, physi­ ology, and animal behavior. Analogous com­ parative methods are used in other scholarly fields such as philology. The term comparative psychology appears to have arisen as a synonym for animal psychology through an implied com­ parison between animal and human behavior.