luca
n. uncountablen. the single living thing from which all life on Earth today began. It lived billions of years ago and is the common ancestor of every plant, animal, and bacteria.
n. the most recent organism from which all organisms now living on Earth have a common descent. An acronym for Last Universal Common Ancestor, it represents the root of the tree of life.
Scientists study genes to learn about LUCA.
Researchers believe LUCA likely lived near deep-sea hydrothermal vents where chemical energy was abundant.
By identifying genes shared across all three domains of life, biologists can reconstruct the metabolic pathways that were likely present in LUCA over three billion years ago.
Usually written in all capitals as an acronym; often used without an article or with 'the'.