Luca
Last Universal Common Ancestor (LUCA) Some authors equate models of the origin of life with LUCA, the Last Universal Common Ancestor of all extant life.[17] This is a serious error resulting from failure to recognize that L refers to the last common ancestor, not to the first ancestor, which is much older: a large amount of evolution occurred before the appearance of LUCA.[18]
Gill and Forterre expressed the essential point as follows:[19]
LUCA should not be confused with the first cell, but was the product of a long period of evolution. Being the "last" means that LUCA was preceded by a long succession of older "ancestors."