THE RNA WORLD AND ITS ORIGINS

The theory of the ''RNA World'' states that the first molecular system s to display the properties of self-replication and evolution were RNA molecules. The origin of life not only depended crucially upon this e vent, but RNA molecules can even be viewed as the first ''living'' thi ngs. In recent years this theory has gained ascendancy over competing ideas and is now largely accepted by biologists as the most satisfacto ry explanation for the origin of life. The reasons for this developmen t will be reviewed and the problem of the origin of the first RNA mole cules will be discussed.