Our Oldest Ancestor Was Surprisingly Sophisticated
For some time, I have been following research on LUCA—the last universal common ancestor of all life on Earth. This short article draws mainly on recent work, especially the 2024 paper by Moody and colleagues, as an introduction to current thinking. What makes LUCA so compelling is the scale of the question it represents. This is not just another organism in the history of life, but the most recent point from which all modern biology descends. What seems increasingly clear is that this starting point was not simple in any everyday sense of the word. Many of us picture the earliest life as fragile and barely formed—a transitional step between chemistry and biology. In that picture, complexity emerges slowly over immense stretches of time. Current evidence points in a different direction. LUCA appears to have been a recognisable, free-living microbe rather than a primitive intermediate. It likely possessed core systems we associate with modern cells, including: A genetic code and...