Structure: RNA structure and diversified life

We discuss the reconstruction of global phylogenies that incorporate RNA structural evidence and how they potentially reveal the evolutionary patterns associated with the emergence of modern biochemistry and early life. Since evolutionary direction and the rooting of the tree of life are fundamental and inevitable issues in evolutionary biology, we also discuss how the use of RNA structural evidence can be established and improved in order to gain insights into deep evolution of ancient molecules. We show that studies consistently and congruently identify the same or similar basal groups on the tree of life derived by using various molecular systems. We summarize the results and discuss the rooting strategy in studying the tree of life.