The Cambrian Explosion

The Cambrian Explosion was a period around 541 million years ago when many diverse animal groups appeared rapidly in Earth's oceans. This event marked a significant increase in the complexity and variety of life forms, including the first known ancestors of many modern animals. Scientists believe it was driven by factors like increased oxygen levels, development of new genes, and changes in the environment. Although called an "explosion," it was more of an evolutionary burst, resulting in a foundational diversification that shaped the course of life on Earth.