  Evolution of life on earth was governed, primarily, by natural selection,
with major contribution of other evolutionary processes, such as neutral
variation, exaptation, and gene duplication. However, for biological evolution
to take off, a certain minimal degree of complexity is required such that a
replicating genome encodes means for its own replication with sufficient rate
and fidelity. In all existing life forms, this is achieved by dedicated
proteins, polymerases (replicases), that are produced by the elaborate
translation system. However, evolution of the coupled system of replication and
translation does not appear possible without pre-existing efficient
replication; hence a chicken-egg type paradox. I argue that the
many-worlds-in-one version of the cosmological model of eternal inflation
implies that emergence of replication and translation, as well as the major
protein folds, by chance alone, as opposed to biological evolution, is a
realistic possibility and could provide for the onset of biological evolution.
Hence an RNA world, as it is currently conceived, might have never existed
although catalytic activities of RNA were, probably, critical for the onset of
biological evolution and its early stages.
