The earliest life forms (gray '?') were probably in existence at least 4 billion years ago (4 Ga), and, as depicted, would have evolved along different branches.
The last universal common ancestor (LUCA), or universal cenancestor, depicted with a yellow '?' is the prokaryotic organism hypothesized as being at the ancestral root of all living organisms. Not the earliest or simplest living organism, and not necessarily the sole example of its type, this organism possessed the genetic material that diverged (about 3.5 Ga) into all current living organisms. A number of terms are employed to refer to the universal cenancestor – last universal ancestor (LUA), last common ancestor (LCA), or last universal common ancestor (LUCA).
αΩ Beginning αΩ Geological Time ▫ site map
tags [Evolution] [universal cenancestor] [LUA] [LCA] [last universal common ancestor]