major transition in Earth history

Major transitions in Earth’s history include the emergence of life, the rise of complex organisms, and significant climate changes. Life began over 3.5 billion years ago with simple microorganisms. About 600 million years ago, multicellular life emerged, leading to a rich diversity of species. The Cambrian explosion about 541 million years ago marked a rapid increase in life forms. The transition from the Age of Dinosaurs to mammals, following a mass extinction 66 million years ago, reshaped ecosystems. More recently, human evolution has influenced the planet, bringing about changes in climate and biodiversity that continue to unfold.