What dramatic changes happened before the Precambrian?
1. Earth's crust formed: The formation of the Earth's crust through volcanic activity and tectonic plate movements led to the creation of land masses and oceans.
2. Formation of the atmosphere: During this time, the Earth's atmosphere began to develop, primarily composed of gases such as water vapor, carbon dioxide, methane, and ammonia.
3. Origin of life: The Precambrian witnessed the emergence of simple, single-celled organisms such as bacteria and archaea, marking the beginning of life on Earth.
4. Oxygenation event: One of the most significant changes during the Precambrian was the Great Oxidation Event, where oxygen levels in the atmosphere increased due to the evolution of photosynthetic organisms.
5. Formation of continents: The process of continental drift and plate tectonics led to the gradual formation and breakup of supercontinents, shaping the Earth's landmasses over time.