chapter  15
Root of Life
Pages 25

The usage of the universal genetic code basically by all living organisms with only minor variations points to the descent of all living species from a Last Universal Common Ancestor, or LUCA, at the root of the tree oflife. Knowledge of the nature of LUCA is pivotal to understanding the pathways that gave rise to LUCA, as well as the pathways that led from LUCA to present day life.