Phylogenetic Diversity and Evolution of Predatory Prokaryotes

Abstract

Predation is one of the commonest types of interaction in the living world. Its roots appear to be ancient, and it may have first occurred early in the evolution of life forms. Predators have evolved many times in the animal realm, and this also seems to be the case within the prokaryotes. Although still rather limited, our knowledge of obligate and non-obligate bacterial predators suggest that they are common in many bacterial phyla, as well as in the environment. In this work, we survey and describe the known bacterial predators according to their phylogenetic affiliation. A hallmark of many bacterial predators is their ability to degrade the polymeric structures of their bacterial preys. An additional characteristic of known obligate predators is a small cell size. We use such distinguishing features to put forward hypotheses relating to the origin of predation in prokaryotes and to the impact of predation on the evolution of the eukaryotic cell.