Getting the most out of reductionist approaches in comparative biochemistry and physiology.

This review serves as an introduction to a Special Issue of CBP focused on the use of reductionist approaches to explore questions in comparative biochemistry and physiology of animals. An overarching goal for research is to provide new insight and knowledge to advance the field. The significance of the research is dependent upon utilizing the most appropriate approach to get the most reliable data, which requires being knowledgeable about the experimental system and its limitations. It is not a trivial task to decide which level of biological organization is best suited to answer the question of interest, because each choice is a balance between strengths and weaknesses. Reporting caveats and limitations is perceived to detract from the definitiveness and value of a study, and so these are typically avoided, or included begrudgingly to appease a reviewer. Reductionist approaches are most valuable when the results can be translated to other biological levels of organization, providing physiological context for the work. Such extensions must also be accompanied by the appropriate assumptions and caveats arising from both the experimental system or its translation to higher levels of biological organization. In preparing this review, we seek to encourage authors to share the weaknesses and caveats in their approaches, and address the challenges associated with demonstrating the relevance of a reductionist approach to higher levels of organization.