User:Clbabcock/sandbox

Origins

I also want to reorganize the origins section and go more in depth of the origin of viruses hypotheses.

Viruses are ancient. Studies at the molecular level have revealed relationships between viruses infecting organisms from each of the three domains of life and viral proteins that pre-date the divergence of life and thus the last universal common ancestor. This indicates that some viruses emerged early in the evolution of life, and that viruses have probably arisen multiple times.

There are three classical hypotheses on the origins of viruses and how they evolved:

• Virus-first hypothesis: This is the idea that viruses could have evolved from complex molecules of protein and nucleic acid before cells first appeared on earth. This hypothesis also states that viruses contributed to the rise of cellular life. This is supported by the idea that all viral genomes encode for the genetic sequences that are lacking in cellular homologs. The virus-first hypothesis was quickly dismissed because it contravened the definition of viruses, in that they require host cells.
• Reduction hypothesis: This idea states that viruses may have once been small cells that parasitized larger cells. This is also known as the degeneracy hypothesis. This hypothesis is supported by the discovery of giant viruses that have similar genetic material to parasitic bacteria. However, the regressive hypothesis did not explain why even the smallest of cellular parasites do not resemble viruses in any way.
• Escape hypothesis: This discusses the idea that some viruses may have evolved from bits of DNA or RNA that "escaped" from the genes of a larger organism. It is also known as the vagrancy hypothesis. This hypothesis doesn't explain how the presence of structures that are unique to viruses are not seen anywhere in cells. This also did not explain the complex capsids and other structures on virus particles.

Virologists are, however, beginning to reconsider and re-evaluate all three hypotheses.

Transmission

One of the things I want to work on is talking about viral transmission. I will add the following information:

Viruses have been able to continue their infectious existence due to evolution. Their rapid mutation rates and natural selection has given viruses the advantage to continue to spread. One way that viruses have been able to spread is with the evolution of virus transmission. The virus can find a new host through:

• Droplet transmission- passed on through body fluids (sneezing on someone)
• Airborne transmission- passed on through the air (brought in by breathing)
• Vector transmission- picked up by a carrier and brought to a new host
• Waterborne transmission- leaving a host, infecting the water, and being consumed in a new host
• Sit-and-wait-transmission- the virus is living outside a host for long periods of time

There are also some ideas behind the idea that virulence, or the harm that the virus does on its host, depends on a few factors. These factors also have an effect on how the level of virulence will change overtime. Viruses that transmit through vertical transmission(transmission to the offspring of the host) will evolve to have lower levels of virulence. Viruses that transmit through horizontal transmission(transmission between members of the same species that don't have a parent-child relationship) will usually evolve to have a higher virulence.

Editing an Article

I will be working on editing the Viral Evolution article. I would like to improve the introduction along with adding more details about the different ideas behind viral evolution.

Here are some sources that I have found so far to help me:

Article Evaluation on Virus Classification

• Is everything in the article relevant to the article topic? Is there anything that distracted you? Yes, everything in the article was relevant to the article topic. There wasn't anything that distracted me.
• Is the article neutral? Are there any claims, or frames, that appear heavily biased toward a particular position? The article was neutral. It was all information based and there were no opinions given.
• Are there viewpoints that are overrepresented, or underrepresented? I didn't think that there were. Everything was well explained in a lot of detail.
• Check a few citations. Do the links work? Does the source support the claims in the article? The links work. The sources do also support the claims in the article.
• Is each fact referenced with an appropriate, reliable reference? Where does the information come from? Are these neutral sources? If biased, is that bias noted? There seems to be many areas where there are proper citations that are appropriate and reliable. The information is coming from articles and websites that appear to be neutral. There are many sections, however, that are missing citations.
• Is any information out of date? Is anything missing that could be added? I don't see that there is any information that is out of date or missing.
• Check out the Talk page of the article. What kinds of conversations, if any, are going on behind the scenes about how to represent this topic? There are actually many conversations that have happened with this article. Many of them are discussing on if information should be there or if it should be changed at all.
• How is the article rated? Is it a part of any WikiProjects? The article is rated as Start-class and appears to be of interest to three WikiProjects.
• How does the way Wikipedia discusses this topic differ from the way we've talked about it in class? I feel that the article goes more in depth of other classification systems than were gone over in class.

Editing and Citing an Article

I am looking at the Virus Classification article. There is a section called LHT System of Virus Classification that needs a citation. The section claims that:

"The LHT System of Virus Classification is based on chemical and physical characters like nucleic acid (DNA or RNA), Symmetry (Helical or Icosahedral or Complex), presence of envelope, diameter of capsid, number of capsomers. This classification was approved by the Provisional Committee on Nomenclature of Virus (PNVC) of the International Association of Microbiological Societies (1962)."

The classification was proposed by Andrew Lwoff and his colleagues, Horne and Tournier in 1962. This was the first comprehensive idea for the classification of all viruses.