Antibiotics and Bacterial Evolution

After reading the article “Antibiotic Resistance of Bacteria: An Example of Evolution in Action?” By Dr. Georgia Purdom, I have a new view on bacterial mutations caused by to antibiotic medications. In her article, Dr. Purdom claims that bacteria are becoming resistant to antibiotics, but that they aren’t evolving. Although I agree with most of what she illustrates, I am skeptical of her claim.
I learned many things about bacteria and antibiotics from Dr. Purdom’s article. One of the many things that I learned is that more than 70% of the bacteria that cause hospital-acquired infections are resistant to at least one of the antibiotics used to treat them. Bacteria are constantly changing so that they can survive in their constantly changing environment. The most important thing this article taught me is that there is very much to be learned about bacteria.
Antibiotics are capable of changing the bacteria’s DNA, in a process that we call mutation, which is why some bacteria have become resistant to antibiotics. Mutation and natural selection often result in bacteria with defective proteins that have lost their normal functions. Dr. Purdom claims that bacteria aren’t evolving, because resistance to antibiotics isn’t anything new and evolution requires a gain of functional systems. Although most mutations result in the bacteria losing functions, I believe that occasionally a mutation can occur that makes the bacteria stronger and better. I think that some strands of bacteria are currently evolving because of the mutations that antibiotics subjected them to.
There is not enough evidence to prove that bacteria are or are not evolving. Dr. Purdom has some good support in her article for her claim that bacteria aren’t evolving. She states “Bacteria that are resistant to modern antibiotics have even been found in the frozen bodies of people who died long before those antibiotics were discovered or synthesized”. This supports the idea that just because bacteria become resistant to antibiotics, doesn’t mean that the bacteria is gaining a new function and therefore evolving. This is good support, but it isn’t enough to prove that bacteria are not evolving.
After reading Dr. Purdom’s article, I am still too skeptical believe her claim that bacteria aren’t evolving. I believe that mutations of bacteria can give the bacteria functions, other than resistance to antibiotics, that we are not yet aware of yet.