The Eocene epoch is a geological time period that occurred approximately 56 to 33.9 million years ago. It is characterized by a period of global warming and high levels of carbon dioxide in the atmosphere, leading to a more tropical climate and diverse flora and fauna. This time period saw the evolution of many modern mammal and plant species, as well as significant changes in ocean currents and sea levels. Research in the Eocene epoch focuses on understanding the climatic and environmental conditions during this time, as well as the evolution and diversification of life on Earth.