Abstract

How do biologists pursue generalizations given the heterogeneity of biological systems? This paper addresses this question by examining an aspect of scientific generalization that has received little philosophical attention: how scientists _express_ generalizations. Although it is commonly assumed that a scientific generalization takes the form of a representation referring to a property that is shared across a range of things, scientists sometimes express their ideas about generality by displaying multiple representations in certain configurations. Such configurations highlight commonalities between different target systems without eliminating system-specific differences. I analyze visual representations in review articles about collective cell migration as a case study. This illustrates that different types of visualizations, including single diagrams and configurations of multiple representations, function in a complementary way to promote understanding of, and reasoning about, generality, specificity, and diversity of biological mechanisms. I also discuss roles of generalizations in scientific investigations more broadly. I argue that an important role of generalizations in scientific research is to mediate and facilitate cross-fertilization among studies of different target systems. Multiple generalizations in research on collective cell migration together provide perspectives from which different biological systems are characterized and compared. They also provide heuristic hypotheses for studying less-explored systems as well as a basis for comparing developmental, pathological, and regenerative processes. This study sheds new light on how scientists pursue generalizations while embracing system-specific details. It also suggests that philosophical discussions should pay more attention to not only what representations scientists construct, but also how they present such representations.