Modelling the selective adaptation of Darwin’s Finches

Abstract Selection and adaptation are two fundamental processes of biological change. Change, which emanates from internal, microscopic properties, eventually leads to alterations in macroscopic patterns. There is much interest in modeling selection and adaptation using reductionistic, genetic approaches. Here, we show that a macroscopic, system-level property satisfactorily models selection. For comparison, three different approaches are employed to model the selective changes observed in a population of Darwin’s Finches. The first two models use a direct relationship between the changes of phenomenological characteristics in response to external perturbations (e.g., fluctuating weather conditions and resource availability). The third approach links adaptation to an ecosystem-level property, total system exergy, using a structurally dynamic model. Results show that although all three models capture basic system dynamics regarding the finch population, the third model most efficiently and accurately simulates system adaptation. This also illustrates that selective pressures may be tracked at the level greater than the individual.