Proteobacteria include many different classes of bacteria with great diversity; however, many share similar metabolic characteristics. What mechanism can best explain this similarity?

Answer: Horizontal gene transfer

Explanation: Horizontal gene transfer is the major means of extending over a large number of the medicine that destroys the capacity of a microorganism to withstand the consequences of treatment that once was able to treat the microorganism. However, it is activity of hereditary substance between single called organisms and organisms that are more than one rather than by the dispatch of carrier of genetic information from mother or father to child.