In this chapter, we introduce the basic principles of biological evolution using examples of rapid evolutionary change that can be observed over the course of a human lifespan. We first describe how our ancestors domesticated common agricultural crops and use the example of domestication to illustrate the three key features of Darwin’s theory of evolution: heredity, variation and selection. The chapter also discusses examples of rapid adaptation in the wild, where selection pressures, e.g. due to predation or pathogens, may be extreme and unpredictable. Finally, we take a detour into the fascinating field of experimental evolution, where laboratory experiments with bacteria are providing increasing insight into the predictability of evolution over timescales spanning tens of thousands of bacterial generations.