Every plant, animal, mushroom, and microbe alive today shares one ancestor—and it lived 4 billion years ago in a boiling sea. 🌍🧬 Meet LUCA: the Last Universal Common Ancestor. Not the first life, but the one from which all life on Earth—you, a redwood, a blue whale, and the bacteria in soil—descends. It was a single-celled microbe that thrived near volcanic vents, surviving on chemical energy. It had no eyes, no brain, no bones. But inside it carried 355 genes, many of which are still inside you today. Think about that: part of your DNA is a 4-billion-year-old molecular heirloom from a world before oxygen, before plants, before animals. Life isn't just connected—it's family. Share the original ancestor of us all. #LUCA #Science #AncientEarth #Evolution #DeepTime #OriginOfLife #Genetics #CommonAncestor #Biology