Reasoning with Diagrams in Chronobiology
Talk Presented to Workshop on Extended Problem Solving, Aarhus, January 2013

William Bechtel
Department of Philosophy, Center for Chronobiology, and
Interdisciplinary Programs in Cognitive Science and Science Studies
University of California, San Diego

Diagrams are widely used to communicate in biology. But what other functions do they play? I will argue that they are often the vehicles of reasoning, both for individuals and collectives. They serve to characterize and conceptualize the phenomenon to be explained. The construction and revision of diagrams is central to the activities of proposing and revising mechanistic explanations of the phenomenon. To illustrate these roles, I will focus on research on circadian rhythms, endogenously generated rhythms of approximately 24-hours that regulate a large range of biological phenomena across all orders of life. Visual representations are crucial to understanding the periodicity and entrainment of these oscillations and to reasoning about the complex interacting feedback mechanisms proposed to explain them.