Labels:bulletin board | reckoner OCR: Replication would be achieved in this example if any given arrangement of the cations in a preformed layer of clay directed the synthesis ofa new layer with an almost identical distribution of cations Selection could be achieved if the distribution of cations ina layer determined how efficiently that layer would be copied So far no one has tested this daring hypothesis in the laboratory On theoretical grounds, however it seems implausible Structural irregularities ir clay that were complicated enough to set the stage for the emergence of RNA probably would not be amenable to accurate self -replication Other investigators have also begun to take up the search for alternative genetic materials In one intriguing example Eschenmoser has created molecule called pyranosyl RNA (pRNA) that is clos ...
(.png)
