What is evolution? The term might refer either to the fact that species have changed over the course of eons, or to the process by which this change has taken place, resulting in their exquisite adaptations and their outstandingly common features. All organisms are related to one another because they have descended from a common ancestor through natural processes that have produced new life forms from preexisting ones. It is important to note that evolution has been taking place on Earth for billions of years. Consequently, although it is still taking place now, much of the information about it comes from the past. Evolutionary scientists do not have a direct view of the past, but they can infer past events from what they currently observe. Overall, there is ample evidence for evolution in fossils, anatomy, biogeography, and DNA.