Abstract
In eukaryotes, RNA processing events, including alternative splicing and RNA editing, can generate many different messages from a single gene. As a consequence, the RNA pool, which we refer to here as the 'ribotype', has a different information content from the genotype and can vary as circumstances change. The outcome of a single RNA processing event often regulates the outcome of another, giving rise to networks that affect the composition and expression of a particular ribotype. Successful ribotypes are determined by natural selection, and can be incorporated into the genome over time by reverse transcription. Eukaryotic evolution is therefore influenced by the alternate ways in which RNAs are processed and the continual interplay between RNA and DNA.
