Bacterial evolution in modern times: Trends and implications for research

Humans have become such a dominant factor on the planet that they have shaped the evolution of many organisms. In some cases, the evolutionary response of the organisms in turn has profound implications for human and environmental health. Nowhere is this more apparent than in the case of bacteria and their evolutionary response to antibiotics, heavy metals and pesticides. This review examines bacterial responses to human-mediated selection on antibiotic and heavy metal resistances and pesticide degradation ability. Although there are differences in the fine details concerning the mechanisms, genetics, origins and selective pressures of these traits, taken as whole, their evolutionary paths are very similar to each other. However, those features which distinguish resistance traits are likely to be important for implementing intervention schemes to reduce the spread of antibiotic resistances and exploiting bacterial traits for bioremediation.