  Following earlier ideas of Dolgov, we show that the asymmetrical dynamical
evolution of fields in the early Universe provides a new source for CP
violation. This can lead to baryogenesis without any additional CP-violating
interactions. The magnitude of this CP violation is time-dependent. In
particular, it vanishes (or is very small) in the late Universe after the
fields have relaxed (or are in their final approach) to their vacuum values. We
provide an explicit example in which our mechanism is realized.
