Bacterial evolution refers to the process by which bacteria change over time through genetic variations. These changes can occur due to mutations, gene transfer, and environmental pressures. Bacteria reproduce rapidly, allowing beneficial traits to spread quickly within populations, leading to adaptations that enhance survival. One significant aspect of bacterial evolution is antibiotic resistance. When exposed to antibiotics, some bacteria may survive due to random mutations or acquired genes from other bacteria. This resistance can lead to the emergence of strains that are difficult to treat, posing challenges in medicine and public health, particularly with diseases caused by Staphylococcus aureus or Escherichia coli.