New Research Suggests a Reason Why God Created Viruses
As I mentioned last week, the Q&A sessions of our outreach events are usually pretty exciting. During this part of the program, it's not uncommon for skeptics to issue challenges to our scientific case for the Christian faith.
One frequently asked question goes something like this: "Why would God create viruses, since these nasty 'bugs' are responsible for so much sickness and disease?" Many people view viruses as an "evil" component of nature. If life stems from the work of a loving Creator, then we wouldn't expect to observe pain and suffering in nature. If, however, the blind, undirected process of evolution generated life, then cruel, troubling features in the natural realm could be easily explained.
So-called "bad" designs may not be as big a problem for the creation model as they first appear to be. Bad designs often turn out to be elegant systems and such is the case for viruses. Even though viruses cause disease, they actually comprise a vital component of nature. For example, recent work indicates that viruses play a key role in nutrient cycling in Earth's oceans.
New research that describes the use of viruses to combat drug-resistant bacteria also suggests another reason why God may have created viruses. Perhaps He made them to serve human needs.
The idea that God made aspects of nature to be of use to humanity is called divine providence. In Christian theology, this idea refers to God's continual role in: (1) preserving His creation; (2) ensuring that everything happens; and (3) guiding the universe. The concept of divine providence also posits that when God created the world He built into the creation everything humans (and other living organisms) would need. Accordingly, every good thing that people possess has been provided and preserved by God, either directly or indirectly.
On this basis, it could be argued that as part of His providence, God created viruses for humanity's use. This may seem counterintuitive, but viruses are turning out to be quite practical for biomedical applications. Recent proof-of-principle experiments performed by scientists from Harvard University and Howard Hughes Medical Center illustrate the utility of these microscopic entities. (To listen to an interview with one of the researchers, go here.)
These researchers are trying to develop a new approach to solving the obstacle of drug resistance in bacteria. Instead of looking for new antimicrobial agents, the scientists decided to make use of viruses that infect bacteria. Known as bacteriophages, some of these viruses can kill bacterial cells by infecting them and then causing them to break apart. The idea is to find viruses that will infect and kill drug-resistant microbes. Unfortunately, targeted cells can develop resistance to naturally lethal phages as well.
Due to of this confounding factor, the researchers decided to use phages nonlethal to microbes because the target cells aren't as likely to develop resistance to them. To make the phages lethal, the team re-engineered the viruses to produce proteins that target nonessential metabolic networks. Again, singling out nonessential metabolic networks makes it less likely that the bacteria will develop resistance to the phage.
As proof-of-principle, the researchers re-engineered a phage that infects E. coli. They inserted a gene into the phage, causing it to produce a protein that inhibits E. coli's so-called SOS response. This metabolic response kicks in when the bacterium's DNA sustains damage and it consists largely of a set of processes that repair the broken DNA.
The infected E. coli was also treated with a class of antibiotics called quinolones. These antibiotics produce compounds that damage DNA and would normally elicit the SOS response. Working together, the quinolones and re-engineered phage blocked DNA repair in the E. coli. Using this strategy, the scientists discovered that it took less antibiotic to kill off E. coli in culture with the phage present than without the phage. Additionally, this approach blocked biofilm formation in E. coli, which is associated with many diseases.
Furthermore, the researchers also showed that their method was effective at killing E. coli resistant to quinolones and, importantly, that it also frustrated the emergence of antibiotic-resistant cells. Two things account for the cell's inability to develop resistance: (1) the depletion of persister cells and (2) the inhibition of the SOS response. Persisters, usually resilient parts of a microbial infection, can evolve antibiotic resistance. The SOS response actually promotes the onset of antibiotic resistance because the DNA repair by the SOS system is error prone, introducing mutations to the DNA that can lead to antibiotic resistance.
Even more exciting, this technique is proven to be broadly effective. Its developers generated the same results using the re-engineered phage with other classes of antibiotics. Furthermore, they produced the same outcome using phages that were re-engineered to inhibit other metabolic systems as well.
But the utility of viruses doesn't stop here. Some researchers have proposed using retroviruses for gene therapy, in which a mutated gene is replaced with a healthy one. Other scientists used retroviruses to successfully transform adult skin cells into induced pluripotent stem cells) that may play a role in cell and tissue replacement therapies. (For an article on induced pluripotent stem cells and their potential biomedical use, go here.)
It's amazing to think that scientists have figured out how to use viruses to develop beneficial technologies. Ironically, the same characteristics that make viruses harmful to life also turn out to be the ideal properties for certain biomedical applications. And in this sense, viruses could be thought of as part of God's providence.
Does that mean that God created pathogenic viruses? I suggest that the answer is yes. Pathogens control plant and animal populations and consequently play an important ecological role. What about viral pathogens that infect humans? In this case, I argue no. Rather, I propose that human viruses evolved from animal viruses, jumping hosts. Recent examples of this phenomenon include the emergence of the HIV and SARS viruses.
This cutting-edge work demonstrates that whether or not one sees a feature of nature as "bad" or "good" often depends on how comprehensively he or she views that particular aspect of nature. As researchers continue to develop new ways to use viruses, I foresee a day in which we view them as an indispensible part of our existence, something that we thank God for.
Other related resources of interest:
10 Breakthroughs of 2010 booklet
"Viruses and God's Providence Revisited" web article
"Why Did God Create Flesh-Eating Bacteria?" e-Zine article