What Common Ancestor Does Everything Share?

Everything alive today must have shared a common ancestor that lived millions or billions of years ago. 

Scientists have spent decades searching for this mysterious single common ancestor that is often referred to as the last universal common ancestor, or LUCA. 

This video by PBS Eons explores the methods used and results of some of the research that have been done to try to find LUCA. 

What do you think? Will we find LUCA or is it lost to time? Let me know your thoughts in the comments below!