Approaches to Abiogenesis
The Origin of Life
The most crucial entity in and most basal unit of evolution is the replicator (Zachar, 2010).
“Replicator First” Approaches
RNA World hypothesis — Since the 1982 discovery of ribozymes (Kruger et al.) proved that RNA had catalytic properties, and could therefore “act both as information carrier and as catalyst” (Alberts et al., 2002), resolved the DNA-protein “chicken & egg” paradox by demonstrating that RNA could act as both “chicken” and “egg” (Bernhardt, 2012; Sankaran, 2013), the replicator-first approach has quite naturally come to be dominated by the “RNA World” hypothesis (von Meijenfeldt, 2013) and this has only been reinforced by the now much-expanded catalytic repertoire of RNA and the import thereof with regard to key cellular reactions (Doudna & Cech, 2002) “which can be viewed as molecular fossils of an earlier world,” meaning we never fully transitioned out of the RNA World (Alberts et al., 2002). Evidence indicating that the common ancestor of the Archaea and the Bacteria possessed an RNA-based genome (Leipe & al., 1999) and only after divergence each separately acquired DNA from DNA viruses, in which DNA first arose (Leipe & al., 1999; Forterre, 2002), has further reinforced this hypothesis.
“Metabolism First” Approaches