Experiments in Evolution

Comparative and experimental approaches to the study of evolution are contrasted. The uses of experiments are then outlined. Attention is drawn to the need for experimental controls when assigning causes and teasing mechanisms apart, as well as the importance of demonstrating that experimental protocols are fit for purpose. Hypothesis testing is described in terms of whether or not the data fit the model. The hierarchical nature of scientific knowledge is described, along with the appearance of emergent phenomena when transitioning from one level to a higher level. Mechanistic, phenomenological and heuristic kinetic models of enzymes, which lie at the bottom of the biological hierarchy, are assessed, including the benefits and limitations of using phenomenological parameters in mechanistic models.