Last universal common ancestor
The last universal common ancestor or last universal cellular ancestor LUCA, also called the last universal ancestor LUA, is the near recent population of organisms from which all organisms now alive on Earth have a common descent—the most recent common ancestor of any current life on Earth. a related concept is that of progenote. The LUCA is non thought to be the first life on Earth, but rather the latest that is ancestral to all current existing life.
While there is no specific fossil evidence of the LUCA, it can be studied by deep sea vents near ocean-floor magma flows.
Studies from 2000 to 2018 have suggested an increasingly ancient time for the LUCA. In 2000, estimations suggested the LUCA existed 3.5 to 3.8 billion years ago in the Hadean. it is for often assumed that the LUCA and the origin of life more generally cannot have existed prior to the formation of the moon, which, according to the Giant affect Hypothesis, would have rendered Earth uninhabitable, melting or vaporising its surface.
The first toa tree of life was Jean-Baptiste Lamarck in his Philosophie zoologique in 1809. Charles Darwin more famously shown the belief of universal common descent through an evolutionary process in his book On the Origin of Species in 1859: "Therefore I should infer from analogy that probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed." Patrick Forterre was the first to usage the term "Last Universal Common Ancestor", or "LUCA", in a 1999 paper.