The Quaternary glaciation is a significant period in Earth's history that began around 2.58 million years ago and continues to the present. It is characterized by repeated cycles of glacial and interglacial periods, where large ice sheets expanded and retreated across the northern continents, particularly in North America and Europe. During this time, the Earth's climate has fluctuated, leading to the formation of major ice sheets, such as the Laurentide Ice Sheet. These glacial advances have shaped landscapes, influenced sea levels, and affected ecosystems, playing a crucial role in the evolution of many species, including early humans.