Evolution of Major Life Forms

Evolution of Major Life Forms

The evolution of major life forms tells how life developed from simple organisms to complex creatures over billions of years. It reveals key changes that led to the rise of diverse species and ecosystems. Fossils, DNA evidence, and structural comparisons help scient...

Earth is about 4.5 billion years old. In its early days, it was a hot, rocky planet. But over time, it cooled, making life possible.

The first life forms were tiny, single-celled organisms that appeared around 3.5 to 4 billion years ago.

Then, about 3 billion years ago, some organisms developed the ability to use sunlight to produce ...