The aim of this virtual special issue is to bring together philosophical and historical perspectives to address long-standing issues in the interpretation, utility, and impacts of quantitative genetics methods and findings. Methodological approaches and the underlying scientific understanding of genetics and heredity have transformed since the field's inception. These advances have brought with them new philosophical issues regarding the interpretation and understanding of quantitative genetic results. The contributions in this issue demonstrate that there is still work to be done integrating (...) old and new methodological and conceptual frameworks. In some cases, new results are interpreted using assumptions based on old concepts and methodologies that need to be explicitly recognised and updated. In other cases, new philosophical tools can be employed to synthesise historical quantitative genetics work with modern methodologies and findings. This introductory article surveys three general themes that have dominated philosophical discussion of quantitative genetics throughout history: (1) how methodologies have changed and transformed our knowledge and interpretations; (2) whether or not quantitative genetics can offer explanations relating to causation and prediction; and (3) the importance of defining the phenotypes under study. We situate the contributions in this virtual special issue within a historical framework addressing these three themes. (shrink)

Karen Neander’s (1991a, b) Selected Effects (SE) theory of biological proper functions argues that the function of a trait is the action for which it was “caused” to be selected by natural selection. Her life’s work has already left a lasting impact, however SE theory has yet to be more properly formalized as a conceptual analysis of biological functions. Although other SE theories have sought to build upon Neander’s work (e.g., Garson, 2017), there remains an ambiguity in the theory’s use (...) of causal descriptors. For the success of her successors, delineating the function of causality for SE theory is of utmost importance. Here, I systematize Neander’s theory according to the different senses of causation inherent to it. I argue that structuring SE theory in terms of causal transitivity and intransitivity reveals that Neander’s analysis not only supersedes her detractors but likely exposes areas of vulnerability in others’ SE theory derivatives. (shrink)