ABSTRACT
This chapter explains and illustrates the fundamental concepts of evolution. It covers fitness, adaptation, natural selection, populations, individuals, traits, evolutionary events, evolutionary processes, the environment, and drift. Careful attention is paid to distinguishing similar distinct meanings of the relevant terms, and concrete examples are used to clarify the concepts. Evolution by natural selection is distinguished into two types: narrow evolution by natural selection, defined via heritable variation in fitness, and broad evolution by natural selection, defined via the systemic advantage of a type.
