The RNA World referred to an hypothetical stage in the origin of life on Earth. Sidney Altman
Three revolutions mark the history of life on earth. The first was the origin of life itself... The second... was the origin of multicellular organisms... The origin of human consciousness... was the third... Life became aware of itself, and began to transform the world of nature to its own ends. Richard Leakey
The origin of life is one of the great outstanding mysteries of science. Paul Davies
Scientists have no agreed theory of the origin of life - plenty of scenarios, conjectures and just-so stories, but nothing with solid experimental support. Paul Davies