Tuesday, 16 March 2004
Defining Fitness: A Measurement Theoretical Approach
Günter P. Wagner
Yale University
12:05 pm, 817R Cathedral of Learning

Abstract: Fitness is one of the fundamental concepts of biology, but yet its definition is still controversial. In this talk I will present a solution to the problem of how to define fitness by utilizing tools and concepts from measurement theory. Measurement theory is a branch of applied mathematics that deals with the relationship between empirical structures and the numerical structures that represent them, i.e. quantitative concepts or scales. The basic idea is that fitness is a measure of competitive ability with certain projectability properties. From that it is argued that fitness can be defined in terms of a pair comparison system based on an operational definition of competitive ability. I will present a new metrization theorem to accommodate this definition and show that from that metrization theorem the basic equation of population genetic theory, the Wright selection equation, can be derived.