LUCA: Last Universal Common Ancestor

STORY

LUCA: Last Universal Common Ancestor

By Michael Alan Prestwood

Thu 16 Sep 2021

Published 4 years ago.

Updated 2 weeks ago.

Evolution

LUCA: Last Universal Common Ancestor

3.75 Billion years ago (+/- 100 million)

DNA, Ribosomes, and ATP

Our common ancester and not even the first DNA Life. From chemical reactions before 4 billion years ago to replicating molecules about 4 billion years ago to DNA based life then to LUCA, the only DNA based branch to survive. Meaning, DNA based life likely started before LUCA, and LUCA is the only branch to survive the test of time. From LUCA to humans, RNA and DNA are essentially the same as today. They serve as the tools for genetic information storage, transmission, and expression through prokaryotes to eukaryotes, underpinning the diversity and complexity of life on Earth. The last universal common ancestor (LUCA) is estimated to have lived approximately 3.65 to 3.85 billion years ago. It is the organism from which all current life on Earth descended from. Your greatest grandparents.

Imagined image: LUCA in a variety of shapes that they might have resembled, set in an ancient, deep-sea hydrothermal vent environment.

Domain: Pre-Domain > Kingdom: Not applicable
(Common ancestor to the Bacteria, Archaea, and Eukaryota kingdoms)

LUCA: The name for our common DNA ancestor...and it wasn't alone.

3.6 Billion BCE

— map / TST —

Michael Alan Prestwood
Author & Natural Philosopher

Prestwood writes on science-first philosophy, with particular attention to the convergence of disciplines. Drawing on his TST Framework, his work emphasizes rational inquiry grounded in empirical observation while engaging questions at the edges of established knowledge. With TouchstoneTruth positioned as a living touchstone, this work aims to contribute reliable, evolving analysis in an emerging AI era where the credibility of information is increasingly contested.