Continental drift has profoundly altered the Earth's geography, leading to the isolation and diversification of species. The movement of tectonic plates causes changes in climate, sea levels, and the availability of habitats, creating new evolutionary pressures. Glacial cycles, characterized by periods of glaciation and interglacial warming, have also significantly impacted life. These cycles cause shifts in vegetation zones, alter sea levels, and can lead to mass extinctions or adaptations as organisms respond to changing environmental conditions.