What Happens When Viruses Evolve

All living things must exhibit the same set of characteristics in order for them to be classified as living (or once living for those that have died off at some point in time). These characteristics include maintaining homeostasis (a stable internal environment even when the external environment changes), ability to produce offspring, an operating metabolism (meaning chemical processes are happening within the organism), exhibiting heredity (the passing down of traits from one generation to the next), growth and development, responsiveness to the environment the individual is in, and it must be made up of one or more cells. How Do Viruses Evolve and Adapt? Viruses are an interesting topic virologists and biologists study due to their relationship to living things. In fact, viruses are not considered to be living things because they do not exhibit all of the characteristics of life that are referenced above. This is why when you catch a virus there is no real â€Å"cure† for it. Only the symptoms can be treated until the immune system hopefully works it out. However, it is no secret that viruses can cause some serious damage to living things. They do this by essentially becoming parasites to healthy host cells. If viruses are not alive, though, can they evolve? If we take the meaning of â€Å"evolve† to mean change over time, then yes, viruses do indeed evolve. So where did they come from? That question has yet to be answered. Possible Origins There are three evolutionary-based hypotheses for how viruses came into being, which are debated among scientists. Others dismiss all three and are still looking for answers elsewhere. The first hypothesis is called the â€Å"escape hypothesis.† It was asserted that viruses are actually pieces of RNA or DNA that broke out, or â€Å"escaped† from various cells and then began invading other cells. This hypothesis is generally dismissed because it does not explain intricate viral structures, such as capsules that surround the virus, or mechanisms that can inject the viral DNA into host cells. The â€Å"reduction hypothesis† is another popular idea about the origin of viruses. This hypothesis claims that viruses were once cells themselves that became parasites of larger cells. While this explained much of why host cells are needed for viruses to thrive and reproduce, it is often criticized for the lack of evidence, including why small parasites do not resemble viruse s in any way. The final hypothesis about the origin of viruses has come to be known as the â€Å"virus first hypothesis.† This says viruses actually predated cells — or at least, were created at the same time as the first cells. However, since viruses need host cells in order to survive, this hypothesis does not hold up. How We Know They Existed Long Ago Since viruses are so small, there are no viruses within the fossil record. However, since many types of viruses integrate their viral DNA into the genetic material of the host cell, traces of viruses can be seen when DNA of ancient fossils is mapped out. Viruses adapt and evolve very quickly since they can produce several generations of offspring in a relatively short amount of time. The copying of the viral DNA is prone to many mutations in every generation since the host cells checking mechanisms are not equipped to handle â€Å"proofreading† the viral DNA. These mutations can cause the viruses to quickly change over a short period of time, driving viral evolution to be done at very high speeds. What Came First? Some paleovirologists believe that RNA viruses, those that only carry RNA as genetic material and not DNA, may have been the first viruses to evolve. The simplicity of the RNA design, along with these types of viruses’ abilities to mutate at an extreme rate, make them excellent candidates for the first viruses. Others believe, however, that the DNA viruses came into being first. Most of this is based on the hypothesis that viruses were once parasitic cells or genetic material that escaped their host to become parasitic.

Psychosocially Therapeutic Aspects of The Old Man and the...

Psychosocially Therapeutic Aspects of The Old Man and the Sea by Hemingway This exceptional story should be used as a therapeutic aid for hopeless and depressed people who needed a powerful force for continuing struggles of life against fate. They should say as the boy Manolin, Ill bring the luck by myself. In the story the old man tells us It is silly not to hope...besides I believe it is a sin. Hemingway draws a distinction between two different types of success: outer-material and inner-spiritual. While the old man lacks the former, the importance of this lack is eclipsed by his possession of the later. He teaches all people the triumph of indefatigable spirit over exhaustible resources. Hemingways hero as a perfectionist man†¦show more content†¦This sentence proclaims one of the novels themes, the heroic struggle against unchangeable fate. Indeed, the entire first paragraph emphasizes Santiagos apparent lack of success. For example, It made the boy sad to see the old man come in each day with his skiff empty. And most powerfully, The sail was patched with flour sacks and, furled, it looked like the flag of permanent defeat. This type of descriptive degradation of Santiago continues with details of his old, worn body. Even his scars, legacies of past successes, are old as erosions in a fishless desert . All this changes suddenly, though, when Hemingway says masterfully, Everything about him was old except his eyes and they were the same color as the sea and were cheerful and undefeated. This draws attention to a dichotomy between two different types of success: outer, material success and inner, spiritual success.. Also, Santiagos eye color foreshadows Hemingways increasingly explicit likening of Santiago to the sea, suggesting an analogy between Santiagos indomitable spirit and the seas boundless strength. The old man had taught the boy to fish and the boy loved him. Manolin is Santiagos apprentice, but their relationship is not restricted to business alone. Manolin idolizes Santiago?as we are meant to?but the object of this idolization is not only the once great thoughShow MoreRelatedPsychosocial Aspects of the Old Man and the Sea6923 Words   |  28 PagesPsychosocially therapeutic aspects of The old Man and the Sea This exceptional story should be used as a therapeutic aid for hopeless and depressed people who needed a powerful force for continuing struggles of life against fate. They should say as the boy Manolin, Ill bring the luck by myself. In the story the old man tells us It is silly not to hope...besides I believe it is a sin. Hemingway draws a distinction between two different types of success: outer-material and inner-spiritual. While

Shaman as a Hero Free Essays

Illustrate thoroughly the essential characteristics of the shaman by referring to events in the mythical narratives about at least two ancient heroes of this type (e. g. , Gilgamesh, Herakles, and Cu Chulainn). We will write a custom essay sample on Shaman as a Hero or any similar topic only for you Order Now Shaman as a Hero Traditionally, the shaman is a character in a religious position who communicates with the afterlife in some way. By altering forms of consciousness, the shaman is able to encounter and interact with the spirit world. In early myths and tales in oral literature the motif of shaman like characteristics is a trend that is evident. However, in these tales the shaman is intertwined with the stereotypical epic Hero. This creates characters that are complicated and intriguing. Tales such as The Epic of Gilgamesh and The Labors of Herakles display a heroic figure that is not only strong in physique but also possesses a divine connection with the afterlife and the gods. With these attributes, these heroes encounter many obstacles that require more than pure brawn to overcome and venture to dark spiritual places alluding to the afterlife/ underworld. A very common tradition in these oral myths is a conquest of either beasts or some type of wild force that inhibits the shamanistic hero’s culture or people from prospering. In The Epic of Gilgamesh, Gilgamesh is faced with many challenges. One challenge particularly threatens his kingdom. Once Gilgamesh and Enkidu have returned from their forest journey, the goddess Ishtar becomes overcome with lust for Gilgamesh. Gilgamesh refuses Ishtar and out of spite, Ishtar asks her father to send down the Bull of Heaven to punish him, bringing seven years of famine with it. With the help of Enkidu, Gilgamesh wrestles and kills the bull. By doing this, Gilgamesh overcomes the beast for the good of his people. Gilgamesh’s morality and greed is questioned but his ability as a leader never falters. His lust leaves no virgin to her lover, neither the warrior’s daughter nor the wife of the noble; yet this is the shepherd of the city, wise, comely, and resolute. † Nearly the entire tale of Herakles revolves on the hero overcoming some type of impending force, whether that be slaying the Hydra or obtaining the Belt of Hippolyte. None of these tasks di rectly inhibit his people, but they do offer atonement for his own pain/ guilt that he feels for slaying his own children. The heroes’ epic triumphs are much more than just grand acts of strength and bravery, these triumphs offer the hero a chance to grow in spirituality during their journey. Gilgamesh’s defeat of the Bull of Heaven results in the death of his friend Enkidu at the hands of the gods, which therefore sends him on a quest to discover himself and overcome his fear of death by speaking with Utnapishtim. On the other hand, Herakles’ many obstacles offer him the opportunity to put his mind at rest for his past actions. Both heroes’ journeys result in a feeling of peace, accomplishment, and understanding. The Heroes in both of these epics also travel to places that seem to be of another world. By eluding to the afterworld/ afterlife these heroes share another shamanistic characteristic. In The Epic of Gilgamesh the hero travels far and wide in search for the answer to eternal life. Gilgamesh battles two large scorpions that guard an entry into a dark place between two mountains. In this journey he comes across a veiled tavern keeper who warns him of his futile pursuit and sends him onward to a ferryman. This is an allusion to the River Styx, which separates the living world from the dead. During the passage across the sea, the water is constantly referred to as death, and the environment continues to be ominous and haunting. This particular part of Gilgamesh’s journey directly relates him to the shaman. In his search for the answer to eternal life, Gilgamesh interacts with the dead and ventures to places where no mortal had been before. Similar to Gilgamesh, Harakles also ventures to places of the undead. Herakles must travel to the Underworld to take on the vicious guard dog of Hades, Cerberus. This task is the twelfth and final labor of Harakles. In this labor, the theme of the dead is very obvious. Herakles interacts with many â€Å"souls† and spirits. In particular, Herakles encounters phantoms empty of blood. This mention of bloodless creatures directly is related to the dead and life after death. This interaction displays the shaman characteristics of Herakles. Although Herakles is a brut and heroic force that is impending to any opposing challenege; Herakles also shows a great sense of wisdom and understanding of the spirit world. Both of these heroes use their wisdom and shamanistic characteristics to alleviate some type of concern in their life. Herakles’ actions alleviate his guilt, and Gilgamesh’s journey alleviates his overwhelming fear of death. After reviewing and enjoying these myths, I have come to realize that Gilgamesh and Herakles are much more than just a traditional hero. Gilgamesh and Herakles are quite complex characters that have inner struggles as well as physical battles/ challenges. The struggles of these heroes’ spirituality give the reader a sense of connection to the character and offer something that can be directly related to. This spirituality also can be seen as a sense of weakness; however this weakness eventually leads to an overwhelming sense of accomplishment and drives the heroes to seek out the answers that allow for the hero to become stronger in mind and physicality. How to cite Shaman as a Hero, Papers

Types of Performance-based Assessment free essay sample

The key factors that need to be considered when planning an assessment are what award regulations (both governmental and awarding body), and award body standards need to be taken into account.The different types of assessment methods must also be considered, as some are different, depending on whether performance-based assessment of the skills, or knowledge-based assessment of understanding is required. Whatever type is selected must be fit-for-purpose, and consider the overall needs of the assessment criteria and context of the measures of achievement. Whatever type of assessment method is chosen for formative and summative assessment must also take into consideration any prior learning that has been identified.Individual or group assessment is also a consideration, as well as what competencies and criteria are being assessed. The how and who of the assessment planning need to be considered, for the numbers involved, timescales, and availability of individuals. When and where assessments are to be given consideration, as there may be staffing and resource constraints, as well as the practical limitations of where the assessment is to be carried out and when, and within what timescales. We will write a custom essay sample on Types of Performance-based Assessment or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page When, and how feedback will be given is also a consideration, as these are staffing and resource constrained as well.When planning any assessment, any individual learner requirements need to be taken into account, with particular reference to any special additional support of the learner and learning identified. All assessment activities and the planning of these activities should follow the principles of being specific, measurable, achievable, relevant and time bound (SMART). Specific in the sense of activities should only relate to the ‘what’ is being assessed and clearly stated. Measurable in that the assessment is measured against specific criteria and objectives. Achievable in that the correct assessment has been set for the current skills of all parties. Relevant for consistency of results of assessment criteria and activities, and Time bound where target dates are set and agreed.