Summary:
- Scientists believe that all life on Earth, from bacteria to humans, shares a common ancestor that lived billions of years ago.
- Researchers are still trying to determine the exact age of this last universal common ancestor (LUCA), with estimates ranging from 3.5 to 4.1 billion years old.
- Understanding the origins of life on Earth can provide insights into the conditions that allowed life to emerge and evolve, as well as the potential for life to exist elsewhere in the universe.