The efforts of several fields (archaeology, paleontology, geochronology) come together to build our growing knowledge of the planet's past and of humankind's origin and development. They use the results obtained from another important field to reach valid conclusions: analytical chemistry and radiochemistry. In this lecture, we will explore the most widespread methods of absolute and relative dating and give examples of their application to human remains and artifacts collected in various parts of Africa. This information essentially contributes to the contemporary debate about the origin of humans, either from a specific "valley of Eden" near our current meeting place in East Africa, or as more recently some have speculated, from places scattered across the entire African continent.