The history of Earth's life spans approximately 3.5 billion years. It began with simple single-celled organisms in the Precambrian era followed by emergence complex multicellular during Cambrian explosion around 541 million years ago. Over time diverse forms evolved leading to development plants animals and eventually humans. Major events include colonization land age dinosaurs rise mammals. Human evolution started 2 ago Homo sapiens our species. story is marked extinction events adaptations intricate web ecosystems that continue evolve.