Our Oldest Ancestor Was Surprisingly Sophisticated
For some time now, I’ve been following discoveries about our last universal common ancestor, LUCA. I’ve drawn this article together from several sources, especially the 2024 paper by Moody and colleagues, as a short introduction to current thinking. What keeps drawing me back is the scale of the question: if every living thing on Earth belongs to one immense family tree, then LUCA is the deepest ancestor modern biology can meaningfully glimpse. I think many of us picture the earliest life as fragile and barely formed, as if evolution had to crawl for ages before it could produce a proper cell. But newer evidence points in a very different direction. In particular, the 2024 work by Moody and colleagues, using the ALE (Ancestral Lineage Estimation) approach, suggests that LUCA was not some hazy halfway stage between chemistry and life. It already seems to have been surprisingly sophisticated. What strikes me first is just how capable LUCA appears to have been. Current estimates sugg...