The antagonist of this story is unlike the villains we know. In fact, they can’t even be seen with the naked eye. They are viruses. Viruses are non-cellular genetic elements that hijack a host cell in order to use their molecular machinery to reproduce and cause infection. Therefore, by definition, viruses cause a reduction in the fitness of their host. Because viruses harm their host, natural selection favors host genes that make them resistant to viruses. Consequently, this places a selection pressure on the virus to overcome the hosts’ resistance. Simultaneous mutations between the two species enters them into an evolutionary arms race, with the host developing resistance in order to overcome the virus and the virus developing new ways to overcome this resistance – typically though mutation – in order to persist and reproduce. This cycle is known as antagonistic coevolution.
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Using serial passage, the FV complex had the opportunity to adapt to their hosts’ MHC genotype and with this opportunity the virus developed significantly higher fitness, in addition to having increased virulence. The same viral strain subsequently showed decreased fitness and a reduction in the amount of new viral particles they were able to reproduce, when they were exposed to an unfamiliar MHC host genotype. These results correspond to the two assumptions – a trade-off and increased virulence – made under the antagonistic coevolution model and show that there is a selective advantage to a host which is carrying an unfamiliar MHC genotype. Their research demonstrated that increasing the genetic variation in host MHC genotypes can provide a significant obstacle to rapid evolving viral populations. If there is a reduction in host MHC-genotype diversity it can facilitate the evolution of more virulent
In the article “Are Viruses Alive?,” Luis P. Villarreal discusses the effects of viruses on life, while presenting different angles as to whether or not they are alive themselves and arguing about the impact viruses have had on evolution. Through a deeper understanding of viruses and their functions, the scientific community may come to fully appreciate viruses, whether they are living or non-living in themselves, as significant evolutionary components.
Viruses are microscopic particles that invade and take over both eukaryotic and prokaryotic cells. They consist of two structures, which are the nucleic acid and capsid. The nucleic acid contains all genetic material in the form of DNA or RNA, and is enclosed in the capsid, which is the protein coating that helps the virus attach to and penetrate the host cell. In some cases, certain viruses have a membrane surrounding the capsid, called an envelope. This structure allows viruses to become more stealthy and protected. There are two cycles in which a virus can go into: lytic and lysogenic. The lytic cycle consists of the virus attaching to a cell, injecting its DNA, and creating more viruses, which proceed to destroy the host. On the other hand, the lysogenic cycle includes the virus attaching to the cell, injecting its DNA, which combines with the cell’s DNA in order for it to become provirus. Then, the provirus DNA may eventually switch to the lytic cycle and destroy the host.
Viruses, Plagues, and History, written by Michael Oldstone, is an insightful and highly educational book that details the history of, that’s right, viruses and plagues. Through typically dry, yet engaging prose, Oldstone recounts what seems like all of it while simultaneously bringing to light the contributions of those brave scientists who asked themselves, “why.” He focuses his attention on some of the most notable viruses such as smallpox, yellow fever, measles, polio, and later he focuses on more contemporary battles against disease.
The most dangerous diseases of our nation have been streaked out by widespread protection or immunity. This widespread protection has been the effect of an immense vaccination which is also called an immunization that introduces vaccines into the body. In this textbook, it mentions that a vaccine is “a preparation of killed, inactivated, or attenuated microorganisms or toxoids to induce artificially acquired active immunity.” (Tortora 487). Like anything else, there are many individuals who disagree with the common immunity or vaccination in general. These people base themselves off weak and false studies, which they then take and go further to spread their bias misled beliefs. These individuals do all of this without looking at the history,
Every fall season we hear the question; did you get your flu shot yet? It is supposed to protect you from that nasty flu virus that circulates our communities during the fall and winter months. But, did you know that in 2011 the Centers for Disease Control (CDC) Adverse Event Reporting Systems Website (AERS) reported 51 deaths caused by the flu vaccine in the United States (U.S.) (CDC,2012). According to National Vaccine Information Center (NVIC), as of July 2012 there have been more than 84,000 reports of adverse reactions, 1000 vaccine related deaths and over 1600 cases of Guillain- Barre syndrome, a acute form of paralysis, triggered by the vaccine (NVIC.ORG).
Over 200 people have fallen ill after eating at a mom and pop establishment located in Maumee, Ohio.
Scientists are now researching viral swarms to help us better understand the swarms' importance and relationship to these viruses. Swarms are what enable viruses to travel from one region of an organism, like the gut, to another, like the brain. Vignuzzi, a virologist, began researching Polio swarms. at first, but soon changed his focus towards Chickungunya, an emerging virus within the Americas. Vignuzzi discovered that mutations in viruses cause diversity, and diversity enables for better adaptation. However, there must be a balance, as too many mutations will ultimately lead to the viruses' death. He came to the conclusion that
virus” (AAV), because they are able to “insert their genetic material at a specific site
The most widespread skepticism, however, is based on popular belief that vaccine efficacy is just not satisfactory. Arguing against this, experts explain that IFV is a single stranded RNA (ribonucleic acid) virus with no proofreading mechanism, as is common in their DNA counterparts (Brandenburg et al., 2013). The replication phase of its life cycle is prone to multiple mutations, constantly generating new strains of IFV. Scientist have been frustrated by challenges due to “sequence and antigenic diversity” (Burton et al., 2012), which is analogous to
We live in a society that more often than not seeks to make health care decision for us. These decisions often look at treatment for the society as a whole. It does not matter if the individual is healthy, the same treatment is prescribed. What is good for one patient is necessary for all of us. This is especially true when it comes to viral infections. Everyone in Canada is aware of the flu vaccine (shot) because every province has a flu vaccination program. Vaccination is being touted as the must have treatment for the annual flu. It is therefore not surprising that most government health department, medical institutions such as the Center for Disease Control (CDC) and even the Canadian Nursing Organization (CNO) strongly recommend
disease to occur with numerous antigens entering the body at once and that their child will not be able to properly metabolize and excrete the mercury from their body.
In this section of his writing, Carl Zimmer argues that understanding evolution is essential to the field of medicine. Zimmer writes that, "A vaccine may work against one strain of a disease like AIDS, but fail against more common ones because they're only distantly related." As time passes species either adapt to their environment or go extinct. These adaptations or gene mutations can be subtle when compared to the entire population of that species, but over time these small distinctions in their genetic code can result in an entirely different species. Looking at this quote from Zimmer's writing and understanding evolution, we can comprehend that viruses can have different characteristics even though they originated from the same species.
The protective capsid helps the virus escape detection and destruction during the invasion of the host. When the virus reaches the target cell, biochemical reactions between the capsid and cell wall allow the virus to latch on and inject its genome into the cell’s interior. Once inside, the viral genetic material insinuates itself into the host’s DNA or RNA. In an efficient feat of natural bioengineering, the host cell’s genetic machinery now does the rest of the work for the virus. The cell, which had already been making copies of its own genome, now also replicates that of the virus. Coded within the viral material is the blueprint for making more copies of the viral genome. Further instructions command the production of capsids and directions for assembly of new viruses. After the host cell becomes engorged with viruses, it explodes, sending the new
The number of individuals who are unvaccinated or infected in the United States has increased (Sun). Vaccines recommended for children are crucial and result in fewer health risks and greater healthy lifestyles. Proponents agree that vaccines are safe and effective, while opponents disagree and believe that vaccines create more negative outcomes than positive ("Should Any Vaccines..."). Opponents attempt to influence and persuade the majority of individuals to stray away from their viewpoints relating to the encouragement of vaccinating children. The rising percentage of children and parents who reject immunization and protest safe vaccines indicate less triumph for sufficient immunization for the population. There are many detrimental risks that affect unvaccinated children, and supporting childhood vaccinations profoundly benefits each parent and child.
During the last ten years or so, there has been a debate on childhood vaccinations. This debate all started from the acquisition that vaccines cause autism. Since the debate, many parents have been skeptical on whether or not they will get their children vaccinated. From the negative comments that are going around from highly respected people new parents doubt vaccines importance to the world. Parents are concerned, which they should be, about if vaccines are beneficial or harmful to their kid’s health? Some claim that vaccinations are needless and unsafe. With the misleading information in parent’s ears they are stuck with the big question. Should I vaccinate my child?