The geological transformation of Earth from 520 million years ago to the present has been marked by significant changes in tectonic plate configurations, climate, and life forms. Here is a summary of key periods and events: • 520 million years ago (Early Cambrian): This period is part of the Paleozoic Era. The supercontinent Rodinia had already begun to break apart, and the formation of new oceans and continents was underway. • 420 million years ago (Silurian): By this time, the continents were