Embedded systems are engineered systems in which software components and computing are deeply integrated into a larger system that continuously interacts with its environment. Quite often, the actions of human participants are also an integral part. Such integrated systems have become an invisible yet crucial part of our environment, so their continuous and trouble-free evolution is of great importance because of our dependence on their services. In this article, the authors discuss four selected aspects of evolution in embedded systems: the different timescales of evolution, the coevolution of processes and systems, checking evolution at deployment time, and the evolution of tests used to check system correctness.