What is a time line that shows how conditions and organisms have changed on Earth?

A timeline illustrating the changes on Earth includes several key events: the formation of the Earth around 4.5 billion years ago, the emergence of simple single-celled organisms about 3.5 billion years ago, and the development of multicellular life around 600 million years ago. The Cambrian Explosion, approximately 541 million years ago, marks a significant increase in biodiversity. The age of dinosaurs dominated the Mesozoic Era (about 252 to 66 million years ago), leading to the rise of mammals and birds following the mass extinction event around 66 million years ago, which paved the way for the current diversity of life.