All life on Earth can be traced back to a single ancestor, the Last Universal Common Ancestor (LUC), or LUCA. This organism likely lived on Earth only 400 million years after its formation and likely had an early immune system. The study also revealed that while LUCA was a simple prokaryote-like organism, its waste would have been used to create a recycling ecosystem. The results will be published in the journal in 2024. While LUCA is the oldest common ancestor we know of, scientists still don't understand how life evolved from its origins to its early communities.