Thursday, October 3, 2019

Society of American Naturalist Essay Example for Free

Society of American Naturalist Essay Different organisms live in a specific place in the biosphere called their habitat. Through the course of evolution, species have adapted to their environment by growing certain physical structures or developing certain characteristics. Factors such as availability of resources (such as light intensity, water availability and others) contribute to the success of survival among species in the biosphere (Regents prep, 2003). Also, biotic relationships (such as competition, mutualism and others) interact to the dynamics of species survival. Certain species of plants grow abundantly in certain areas only of the biosphere. Some grasses grow abundantly in area where there is ample source of sunlight, but does not grow within forest beds where sunlight is scarce. In the same way, succulent herbs and vines are not commonly seen in dry area like the grassland. This exercise aims to characterize the effect of light intensity to the survival of grassland monocots. Hypothesis Limit in the availability of resources would cause decrease in species productivity and may reduce their chance of survival. For plants that are adapted to direct sunlight exposure may not be able to survive when placed in an environment where there is less amount of light. Methods For this experiment, effects of changes in lighting condition to grassland plant will be tested. To do this, find a grassland area (or any area that are exposed to direct sunlight most time of the day) and select species of low growing monocots. The area should be occupied dominantly by a single species in order to make easy observation. Measure six feet by six feet (6 x 6 ft) working area. Using small peg and nylon string mark the boundary and divide the working area into four equal quadrants. Tag the quadrants as area I, II, II and IV as shown in figure 1. I II III IV Figure 1. Working quadrant in grassland area. Using long sticks and cheesecloth (or any material that would cast greater shadow), make a tent over quadrant III and IV making sure that quadrant I and II are not shaded. The tent will simulate shaded condition and limit sunlight exposure for species in quadrant III and IV, while ensuring that other condition such as, humidity, mineral and water contents of soil and interacting species (insects and other plants) are held constant. In making the canopy, leave at least half foot (0. 5 ft) gap above the tip of the grass so that air can circulate in the area and will not cast shadow in area I and II when direction of sunlight changes. Quadrant I serve as the control while quadrant II serves as a duplicate for the control. Quadrant III is the experimental and quadrant IV is the duplicate. Make a table and list the initial condition of the selected grass species found in all quadrants. Take note of the time observation was made and the condition of the environment such as temperature of the surrounding air and the soil, humidity. Measure the difference in the amount of light in each quadrant. For two weeks, observe any changes in the condition of the grasses, such as leaf color and turgidity in all quadrants. Collect data every two days, preferably the same time when the set up was made. Predictions There will be noticeable changes in the condition of plans found in the given set up. Because these plants are not adapted in colder or shaded area, most leaves of grasses III and IV would have turned yellow and noticed decrease in their turgidity. Some leaves may have already dried out because photosynthesis is not carried out in its maximum potential. Grasses found on quadrants I and II should have remained the same condition as the start of the setup, because all factors necessary for its survival is available. Conclusions A change in the environmental condition and limit of resources affects the chance of species survival. Plants that are found in grassland area that are adapted to prolonged sunlight exposure may not be able to survive when placed in an area where there is a limited supply of sunlight. Part II Evolution of Resistant Bacteria Mutation of infectious bacteria to a resistant strain seems impossible to stop. Biological species are not fixed entities and are subject to ongoing modification through chance and adaptation (Society of American Naturalist, 1998). Organisms (such as bacteria) interact with its environment (their host and medicines) in a very dynamic way that it is biological phenomenon to adapt to these changes. Therefore, evolution of mutant genomes is inevitable. In natural environment, formation of resistant form of bacteria had been found. Antibiotics produced naturally by the soil, waste products and treatment waste are also contributes to evolution of these organisms. Since there is no way of stopping evolution, the only possible solution to this problem is to slower down its process. Though there is no possible way to quantize the evolution process or exactly measure its progress, it is the idea of determining the key point in the evolution process and tackles the issue at that point. Resistant forms of bacteria comes form strains that are not fully killed by antibiotics. There are cases when a patient was instructed to take medicine for a certain period but discontinue taking the medication when they feel that they are already well. However, they do not know that bacteria causing their sickness were just dormant or too few to cause illness. Or some resort to self medication by taking readily available over the counter antibiotics. Medical professionals on the other hand contribute to the matter. Administering prescription drug has been a normal way in treating diseases. However, because of prolonged use to these antibiotics, resistant forms of bacteria evolve. There is theoretical evidence proving application of selective pressure (such as antibiotics in food animals) will result in drug resistance by pathogens attacking human. It may not be easy to get direct evidence but this could help in development of policies (Leidberg, 1997, p. 419). Educating the public about the risk of self medication and drug resistance is a good step. Including this topic to academic lessons is also a good way in reaching peoples attention. Also, it is not just the public who should be serious about his matter. Medical professionals should also be aware of the risk involve in prescribing common antibiotics to most illness. After all, they are the ones that have direct knowledge about medicines and illnesses. Doctors are the ones who can control the prescription of antibiotics and how it should be taken by their patients. References Society of American Naturalist. (1998, December 23). Evolution, Science and Society: Evolutionary Biology and the National Research Agenda. Retrieved March 9, 2008, from http://www. rci. rutgers. edu/~ecolevol/execsumm. html Lederberg, J. (1997). Infectious Disease as an Evolutionary Paradigm. Emerging Infectious Diseases, 3(4), 417-423. Regents Prep (2003) Living Environment: Ecology: Biotic vs. Abiotic. Retrieved March 9, 2008, from http://regentsprep. org/Regents/biology/units/ecology/biotic. cfm

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