One longstanding debate in the field of biology is whether or not viruses should be considered living organisms. Viruses are composed of a protien coat with genetic material contained on the inside. The genetic material can vary from segments of RNA to DNA depending on the type of virus. Unlike all other species not debated as "living," viruses lack the ability to reproduce on their own because of their design. Instead, viruses are only able to reproduce or replicate within a host. By using the machinery present in their host cells, they are able replicate and spread the virus. For those who believe viruses are not alive, this is one of the main points they cite: without a host cell, virsuses would not be able to survive therefore should not be considered alive. The opposition believes viruses should be considered alive because of the success they have at infultrating their hosts and reproducing. Like all other species considered to be living, success by a virus should be determined by their reproductive fitness. Those who are not fit are removed from the population while those fit to survive pass on their ability to the next generation. The niche that viruses find themselves in the ecosystem is one that they have remained in since long before their discovery. Yes, viruses need a host but a host is their niche. If they were not fit for this niche, they would not survive or exist in the living world but they do.
Comments
air quotes
Try to avoid using air quotes
Clumsy wording
Some of the sentences lack internal logic. For example the second clause of this sentence doesn't follow the first "Like all other species considered to be living, success by a virus should be determined by their reproductive fitness." The idea that life is measured by reproductive fitness isn't introduced earlier, and leads to some confusion for the reader.
I would add an introduction
I would add an introduction and a conclusion if it is a paragraph about the debate between the two sides and you have an opinion. If it is something that you are trying to present both sides of, I would separate the two into two paragraphs and add things like rebuttals to build bulk to the paragraph.