Here are some course notes about Halobacteria from Southern Illinois University, Carbondale. Christian de Duve , a Nobel prize winning scientist, has qualms about the RNA World hypothesis. World of Richard Dawkins a page about the ideas and writings of Richard Dawkins. In other words, arguments between science and religion inherently don't make any sense. The review is worth reading.
Microfossils are very important in understanding the Precambrian fossil record.
Cyanobacteria are responsible for putting oxygen into the atmosphere, and are evidently very old. Cyanobacteria are very close to Chloroplasts. Hopanes are pentacyclic and similar to the tetracyclic Steroid nucleus. These have been found in extremely ancient sediments, 3.7 billion years old. The Biomarker Handbook shows some structures of Steranes and Hopanes found in petroleum.