Theory vs. Theory

What does it mean to invoke “evolutionary theory”? Is “neo-Darwinism” (or “Darwinism”) a theory, a school of thought, or something else? What gives a theory structure and meaning (e.g., axioms, themes, formulae)? What is the relationship between mathematical formalisms and other statements of “theory” (e.g., what does it mean for a lecturer to show a key equation of quantitative evolutionary genetics and assert “this is neo-Darwinism” 1)? Who decides how a theory is defined, or redefined (e.g., is Ohta’s “nearly neutral” theory an alternative to, or a variant of, Kimura’s Neutral Theory of Molecular Evolution)?

In this post, we’ll begin the process of developing a shared framework for productively discussing “theory” and “theories”. We will begin by addressing an ambiguity in the use of the word “theory”, partly because this particular ambiguity is important, and partly as an exercise in addressing semantics. 2