Last Universal Common Ancestor

The Last Universal Common Ancestor (LUCA) refers to the most recent common ancestor of all current life on Earth, encompassing all domains of life, including bacteria, archaea, and eukaryotes. Scientists estimate that LUCA existed approximately 3.5 to 4 billion years ago. LUCA is not a specific organism but rather a theoretical construct representing the point in evolutionary history from which all living organisms have descended. It is believed to have been a unicellular organism with a simple structure, possessing the basic biological mechanisms necessary for life, such as the capacity for metabolism, replication, and DNA-based heredity. The study of LUCA helps researchers understand the early evolution of life, the origins of cellular processes, and the genetic relationships among different forms of life today.