The Pliocene epoch is a geological time period that occurred approximately 5.3 to 2.6 million years ago. It is the most recent epoch of the Tertiary period and is characterized by significant climate changes, including the onset of the ice ages. The Pliocene is important for studying the evolution of early humans, as well as the diversification of mammals and other organisms. Research in the Pliocene typically focuses on climate, biodiversity, paleoecology, paleoclimate, and the geological processes that shaped the Earth during this time period.