1.5 Environmental Stress
Environmental change and stress is the most prevalent cause of evolution and mutation in the plasmid of E.coli bacteria. Wild-type bacteria have a wide variety of genes so when environmental change occurs (within permissible parameters), some of the E.coli may survive and their offspring inherit the gene(s) that allowed them to survive. When E. coli bacteria become stressed, they exchange sections of DNA and reproduce quickly to improve chances of survival.