To understand the evolution of planet earth over the period, the Geography student can create a timeline diagram showcasing the Earth in different stages, starting from two billion years ago when Cyanobacteria roamed everywhere. Cyanobacteria are aquatic and photosynthetic. That is, they live in the water and can manufacture their food. The second image showed the condition of Earth one million years ago when the land and water were filled with Lichens. Five hundred million years ago, the Earth was filled with Ferns that ultimately lead to the land vegetation that we have today. As the image suggests, an event timeline is the alignment of time, a chronological statement, to define a certain chain of events or activities that happened at a particular phase.