DRAFT: This module has unpublished changes.

Salma Yehia

Virus Assignment

Natural Science

10/26/12

 

The Virus Debate: Viruses As Vital But Not Living

 

          In recent history, the scientific community has been vigorously debating whether virus’s can be considered living or non-living agents. Viruses are tremendously important to evolution and to biodiversity however, I am hesitant to conclude that these agents are living. In trying to discover some sort of answer to the grand questions of the debates, it is important to analyze three points that can help us shed some light on the question at hand.  A rough list of the characteristics of life has been developed throughout the years to help categorize nature. Although this list can tell a person whether something is considered living or not, it should not be the only method used to determine whether something is living because viruses tend to fall in a gray area that do not simply fall clearly into a certain category. We should also analyze the way in which an agent interacts with the rest of nature to ensure increasing depth to the inquiry of question. Thirdly, as scientists we should not shy away from creating new terminology and categories that don’t necessarily fit into “living” or “non-living”.

 

 

            The categories of life have long been used to determine where a component of nature can be placed under the definition of life. Three important categorizes that may help in labeling a virus are growth/reproduction, cellular organism, and metabolism. I hold a similar view to geneticists when it comes to a virus in relation to growth and reproduction. I concur that the ability to self-sustain is one of the vital determinant factors in whether something is living or not. When assessing viruses, it is obvious that they don’t have the means to self-replicate until they have gained access to a cell. Only afterwards do they hoard off the machinery of the cell to spread. As López-García skillfully states, “viruses have a ‘borrowed life,’ exploiting the cell’s metabolism and resources for their replication” (393). This ‘borrowing’ technique excludes them from being life forms as they are to some degree evolved by the cells themselves.

 

         When looking at the structure of a cell, biologists have acknowledged that viruses are composed of a single strand of genetic information surrounded by a protein coat.

 When comparing a virus to a cellular organism viruses lack much of the needed characteristics such as an enclosure by a cell membrane and certain organization within the cell. If we were to conclude in accordance with the categories of life, a virus would not be considered living. On another point, viruses lack any form of energy and once in contact with the cell, the virus steals energy from the cell. We can then incur that viruses do not have a metabolism and should therefore not be categorized as a life form. However, it’s not so simple to say whether a virus is living in comparison to the categorization of life. This type of categorization yields gray areas because although viruses do not have a cellular structure, they are just as important as cellular creatures. Nature is complex and although categorization of nature is important, placing each agent into neat, clear categories may be close to an impossible task.

 

       

        Scientists need to understand that the way in which viruses come in contact with cells is just as important as what occurs once the virus is attached to the cell. Initially, in the absence of cells, viruses are small and dormant quantities matter. In this stage they are referred to as virions. These virions stay dormant until a cell comes in contact with it, at which point it is referred to as a virus. Usually, the term virions is used simultaneously with the term virus and not clearly distinguished. Some, on the other hand, may suggest that the distinction between the two must be made because one is like the species when it is a fetus—virions— and the other being the actual species after birth—virus within a cell. They conclude that if we are to assess the viruses when they are within the cell, we can conclude that viruses are living. But, they fail to realize that  fetuses and the born living thing don’t resemble one another and that’s why they aren’t considered the same. Nonetheless, because the structure of a virus and virion are the same and do not change they cannot be compared to this. Therefore, referring back to the categorization of life, although viruses gain some mechanics in the cell, they still don’t have their own metabolism, even when they are within a cell. I believe that the distinction between a virus and virion is too slight to consider its significance.  However, by understanding the way in which a virus becomes active we can understand whether or not a virus is living or non-living. However, although the categorization of life concludes that the virus is certainly non-living, the virus does spread rapidly and attacks/engulfs the specific host once in the cell, which leads us to think that a virus may be considered half-living or partially alive.

 

      Scientists are in constant battle in determining whether a virus is living or not. However, maybe the answer is not as complicated as it seems. These scientists probably use traditional terms and ideas that they are comfortable with to categorize viruses. However, that just may be the problem. If new terminologies were created or an alternation of the categories of life was done to accommodate viruses, the debate would be put to a rest.  Scientists should be open to creating a new and different type living organism category. Viruses have been referred to as agents, chemicals, molecular parasites, and even life forms in the past. They might be all true but a virus needs to be specifically defined in a whole new way. Since they are only partially alive, not being able to replicate on their own but having a profound impact on the behavior of the host, they cannot be categorized by the characteristics of life but should not be rejected as influential parts of nature. Guerrero and Piqueras contributed to the virus debate by explaining that “central to biology is cell theory: all life is cellular. Viruses are not living, but lived entities” (178). Their development of a new term, “ lived entities”, describes the virus’s ability to live through cells. Using new terms such as this opens doorways for new perspectives on viruses that support viruses as partially living.

 

 

         Does it matter to know whether viruses are living or non-living? In order for such a question to be answered we must first understand the importance of viruses and their influences on the rest of the natural world.  Viruses infiltrate almost every living organism and are one of the most numerous components of nature. Viruses are especially important and have a direct impact on evolution as well as biodiversity. They control cell populations which “not only contributes to fostering biogeochemical turnover but also to maintaining biodiversity” states López-García (390). This biodiversity is essential to fostering a more productive and stable ecosystem. Lopez-Garcia also realizes that viruses further the evolution of “genes and genomes and mobilize genes across lineages” (391). The fact that viruses help the evolution of genes helps the natural world live healthier and once again, more stable. We may never know in the near future whether viruses are living or non-living. One fact still remains however; viruses are essential to the biodiversity and evolution of the nature world. Because of their importance they need to be given a special place or categorization in the tree of life. Viruses impact each branch and must be incorporated, whether it is through new terminologies, new categorization, or simple modifications, in order to be truly recognized for their astounding influences on nature.

 

References:

 

Guerrero, R., Piqueras, M., & Berlanga, M. (2002). Microbial mats and the search for minimal ecosystems. International Microbiology, 177-188. Retrieved from http://www.im.microbios.org/articles0203/2002/december/04%20Guerrero.pdf.

López-García, P., & Moreira, D. (2012). Viruses in Biology. Evolution: Education and Outreach, 389–398. Retrieved from http://www.springerlink.com/content/7836794363671x03/fulltext.pdf.

DRAFT: This module has unpublished changes.