Categories : Intelligent Design, Evolution, RNA
Editor : MikeGene
published: jeudi 4 janvier 2007 19:02:58
The non-teleological perspective views RNA as a primitive, ancient relic of the process of abiogenesis. The teleological perspective views RNA as a sophisticated molecule that plays an essential control function within the cell and has never existed apart from its cellular context.
While RNA is crucial to all living things, I think eukaryotes have more fully exploited its ability to control the proteome (a cell’s protein complement). A simple fact from cell biology explains this. In prokaryotes, the process of RNA synthesis (transcription) is coupled to the process of protein synthesis (translation). This allows bacteria to more efficiently express their genes and the bacterial cell design is all about efficiency. But eukaryotes trade efficiency for flexibility, and as such, have a nucleus where the genome is physically separated from the ribosomes. This means there is a much larger window of opportunity to process and modify protein-encoding RNA in eukaryotes, which in turn means the greater potential for control. One such control mechanism exploited by eukaryotes is alternative-splicing, where a single gene can give rise to dozens of gene products that are variations on a theme.