pA majority of evolutionary biologists believe that we now can envision our biological predecessors--not the first, but nearly the first, living beings on Earth. iLife from an RNA Worldi is about these vanished forebears, sketching them in the distant past just as their workings first began to resemble our own. The advances that have made such a pursuit possible are rarely discussed outside of bio-labs. So here, says author Michael Yarus, is an album for interested non-biologists, an introduction to our relatives in deep time, slouching between the first rudimentary life on Earth and the appearance of more complex beings. pThe era between, and the focus of Yarus' work, is called the RNA world. It is RNA ribonucleic acid--long believed to be a mere biologic copier and messenger--that offers us this glimpse into our ancient predecessors. To describe early RNA creatures, here called ribocytes or RNA cells, Yarus deploys some basics of molecular biology. He reviews our current understandin