included the formation of resting stages, desiccation-resistant spores or cysts , cell clusters with much reduced surface areato-volume ratios, and copious production of EPS in biofilms or the trapping and binding of protective sediment grains by microbial mats.These strategies would have also resulted in structures with a higher than usual preservation potential for entry into the fossil record. In other words, the proposed evolutionary path and the early fossil records are in accord with the physiological adaptations likely to have arisen in freshwater ecosystems.