The way we quantitate the human genome has changed dramatically. The estimated percentage of the genome derived through retrotransposition has increased (now 45%), as have the estimates for alternative splicing (now 41-60% of multi-exon genes), antisense transcription (now 10-20% of genes) and non-protein coding RNA (now ~7% of full length cDNAs). Concomitantly, the estimated number of protein-coding genes (now ~24,500) has decreased. These numbers support an RNA-centric view of evolution where phenotypic diversity arises through extensive RNA processing and widespread RNA-directed rewriting of DNA enables dissemination of "selfish" RNAs associated with successful outcomes. The numbers also indicate important roles for sense-antisense transcription units (SATs) and coregulatory RNAs (coRNA) in directing the readout of genetic information, in reconciling different regulatory inputs and in the transmission of epigenetic information to progeny. Together, the actions of reading, 'riting, 'rithmetic and replication constitute the 4R's of RNA-directed evolution.