THE BASE IDEA. “Darwinian evolution, as it was first conceived, has two dimensions: adaptation, that is, selection based upon “apt function”, defined as the “good fit” between an organism’s metabolic and biological demands and the environment in which it is embedded; and heredity, the transmissible memory of past apt function.”
https://link.springer.com/article/10.1007/s12304-016-9256-5