The Pleistocene epoch is a geological period that lasted from about 2.6 million to 11,700 years ago. It is characterized by repeated glacial cycles, where large ice sheets covered significant parts of the Earth, particularly in the northern regions. This epoch saw the development of many species, including the emergence of early humans, such as Homo sapiens. During the Pleistocene, the climate fluctuated between cold glacial periods and warmer interglacial periods. These changes influenced the distribution of flora and fauna, leading to the extinction of many large mammals, such as the woolly mammoth and the saber-toothed cat. The Pleistocene set the stage for the modern environment and human civilization.