An integrated modeling approach to assessing linkages between environment, organism, and phenotypic plasticity.

Many of the most interesting questions in organismal biology, especially those involving the functional and adaptive significance of organismal characteristics, intrinsically transcend levels of biological organization. These organismal functions typically involve multiple interacting biological mechanisms. We suggest that subdisciplinary advances have led both to the opportunity and to the necessity to reintegrate knowledge into a new understanding of the whole organism. We present a conceptual framework for a modeling approach that addresses the functioning of organisms in an integrative way, incorporating elements from environments, populations, individuals, and intra-organismal dynamics such as physiology and behavior. To give substance to our conceptual framework, we provide a preliminary focal case study using phenotypic plasticity in the tooth morphology of snails in the genus Lacuna. We use this case study to illustrate ways in which questions about the evolution and ecology of organismal function intrinsically span all organizational levels. In this case, and in many others, quantitative approaches that integrate across mechanisms and scales can suggest new hypotheses about organismal function, and provide new tools to test those hypotheses. Integrative quantitative models also provide roadmaps for the large-scale collaborations among diverse disciplinary specialists that are needed to gain deeper insights into organismal function.