The Ancestor of us all was.....

...a single bacterial cell floating in a warm, shallow sea, 3 1/2 billion years ago. All other life developed from this first simple cell. Each new kind of life was related to the kind that came before it in a long, long chain of life. This changing of one form of life into another over time is called evolution.

Three shapes of bacteria

We know bacteria were the first living things on the planet because scientist have found their fossils in Earth's oldest rocks. Each bacterium was just one cell, so tiny that it was invisible. You'll be needing microscope to see their fossils.

The ancient bacteria looked like the bacteria that are alive today....