SEXUAL STRATEGY AND SIZE DIMORPHISM IN RATTLESNAKES - INTEGRATING PROXIMATE AND ULTIMATE CAUSATION

Integrating proximate and ultimate causes and effects simultaneously i n the study of behavior is challenging and complex, but useful, This i s equivalent to asking both ''How?'' (in the sense of proximate mechan isms) and ''Why?'' (in the sense of ultimate evolutionary payoffs) an organism operates in one way and not another, Sex differences in rattl esnake (i) size and growth and (ii) mating and reproductive strategies and tactics, provide a good theoretical and empirical context in whic h to attempt such integration. We employ interdisciplinary and multidi sciplinary approaches in our behavioral and physiological work, but we mean something different by ''integrative'' that amounts to the simul taneous study of both proximate and ultimate levels of causation and e xplanation. Though not always feasible, this approach represents an im portant goal to work towards because it attempts to represent faithful ly the complexity inherent in living systems. To this end, we also emp loy a variety of modeling approaches, which entrain intuition, generat e new hypotheses, and sharpen inference. Individual-based simulations, for example, offer promise for broad, integrative programs of biologi cal research.