human
What is the most common ancestor among all living organisms?
assistant
The most common ancestor of all living organisms is a single-celled organism called LUCA. This organism lived about 3.8 billion years ago and is thought to have evolved into all modern life forms through a process called endosymbiosis. Endosymbiosis involves the merging of two different cells, such as a bacterium and a protozoan, which eventually leads to a new cell with distinct properties from its parent cells.