Lewontin on quasi independence

Definition of quasi independence In an attempt to understand the process of evolution, Richard Lewontin explained that adaptation is a necessary prerequisite to occurrence of evolution. However, he also believed that it can be workable when the reproductive ability of the organisms and the phenotype of the concerned subject had two particular traits: quasi independence and continuity. Continuity meant that minor changes in traits only affected minor ecological processes; this meant that reproductive fitness could also be marginally affected.Advertising We will write a custom essay sample on Lewontin on quasi independence specifically for you for only $16.05 $11/page Learn More Conversely, quasi independence refers to the fact that there a number of pathways that can lead to change in an organism. Some of these pathways can either lead to negative effects or positive effects on other organs and ecological processes of the subject. However, the negative ef fects of the adaptation are not powerful enough to overcome the fitness increments created by the adaptation (Levins and Lewontin 79). Why Lewontin needed the concept An example of quasi independence is a series of mutations that occur in the body of a zebra so as to change the length of its bones. This change in the physical appearance of the zebra will only lead to adaptation if it has been shown that the zebra’s major threat to survival is the need for speed. If other ecological needs are prevalent, then the change in length of the leg bones will be of no evolutionary relevance. For instance, if a certain predator uses tactical methods to attack the zebra, then the change will not be useful to its survival. Second, it will lead to adaptation if an alteration in speed will not lead to other complications in the organism’s ability to adapt to its environment such as greater metabolism or need for more food. This increased need for food in an environment with limited r esources will offset the positive benefits that emanate from the escape of the zebra from its predators. Third, if the lengthening of the zebra’s bones does not create a negative effect on other parts of the body. The organs need to be able to function in the same way that they did prior to occurrence of the mutation. Longer bones would require greater energy during the developmental process. They would also be more prone to breakage, or could lead to other morphological challenges in the rest of the body. As a result, a change in a certain characteristic would only be relevant to evolution if the net effect of the trait on the whole organism was positive. Lewontin needed quasi independence in order to explain why certain adaptations were evolutionarily significant or not. He needed to place mutation in context such that it would be possible to assess its relative usefulness. Quasi independence allows one to understand what leads to net reproductive fitness with regard to the characteristics that arise in organisms. Whether the theory fits in with Lewontin’s overall view of the evolutionary process Lewontin asserted that organisms existed as integrated wholes rather than products of atomic traits. He believed that if too much emphasis was given to the genes that led to the development of a certain trait, then the organism would be placed at the end point of the evolution process, yet this was not a wise thing to do (Levins and Lewontin 80).Advertising Looking for essay on biology? Let's see if we can help you! Get your first paper with 15% OFF Learn More He argued that if a seedling was small, it did not matter whether a small seed (hence the genes) led to the prevalence of a small seedling or whether the lack of sunlight and effects of gravity were responsible for creation of that small size. All that mattered was that the seedling was small and that it grew slowly or was likely to be shaded by larger plants. Therefore, the organis m was an important part of the evolutionary process because it determined what occurred to it in the future. Similarly, the concept of quasi independence falls in line with this kind of reasoning because it focuses on the holistic effects of an adaptation upon the entire organism and the organism and its environment. In the analysis of this concept, one realises that the organism is the main focal point in natural selection. This was the same thing that Lewontin kept advocating for in his approach to evolution. Lewontin opposed the fact that organisms were objects of external forces by explaining that the natural environment could be altered to suit the needs of organisms also. For example, he often explained that an organism’s niche can be altered in so many ways to suit its needs. For example, insects have the choice of selecting a wide range of leaves, but a number of species of leaves are actually never eaten by those insects. Alternatively, snakes could have had the opti ons of crawling and eating grass, but they do not (Levins and Lewontin 98). There are certain biological and physical traits in the organism that determine what niche an organism will require. This explains why it is not plausible to argue that a niche exists prior to an organisms’ existence. Therefore, the organism will determine what is relevant to it. It is the integrated whole and not some specific genetic factors that will affect its future. Likewise, in quasi independence, he argues that the organism still determines what is relevant to it in terms of adaptation. Although mutations can occur in a variety of ways, it is only the ones that meet the need of the organism that can be defined as adaptively relevant. This means that he was giving focus to the whole rather than the particular traits he was talking about. Conclusion Quasi independence was a necessary concept because it provided an explanation about relative usefulness of mutations. This phenomenon was in tandem with Lewontin’s overall view of evolution because the organism determined the relevance of the mutation and it was also the focal point in the concept. Work Cited Levins, Richard and Lewontin, Richard. On evolution. Harvard: HUP, 1985. Print.Advertising We will write a custom essay sample on Lewontin on quasi independence specifically for you for only $16.05 $11/page Learn More This essay on Lewontin on quasi independence was written and submitted by user Yuliana O. to help you with your own studies. You are free to use it for research and reference purposes in order to write your own paper; however, you must cite it accordingly. You can donate your paper here.

Criticism Analysis Essay Sample

Criticism Analysis Essay SampleCritisism analysis essay samples are in great demand these days. This is the time when things are changing in the world of technology and science. It is not that someone would like to read something and not take action towards it, but the case is rather the opposite. An essay can change the life of a person and can give him or her a lot of relief.There are many opportunities that are provided by these essay samples. Since so many people nowadays use the internet to look for writing services, there are many online writing sites that provide this service to its users. This means that many people are now searching for online essays for free.The truth is that any critique analysis essay sample can also be bought. But it would be better to get one if you can afford it.The essay samples can be bought in either hardcopy or online. Sometimes the critique analysis essay sample will be very expensive, but in other cases it can be offered free of cost. In most cas es, the critique analysis essay sample is available on the internet.However, what makes the critique analysis essay sample more popular is that the writers who are able to analyze the online essay will be paid for it. So, while doing this work, you will earn an income. It is a very good way to make some extra money.These criticisms analysis essay samples are no different from the others. The fact is that the writer will have to find out a few points regarding the essay which will make it easy for the reader to understand the contents. They will then have to compare the ideas which are available in the essay with the rest of the article and find out a conclusion that is on par with what the essay has to say. If all these activities do not give them the right direction, then they can seek help from a mentor.If you want to get a critique analysis essay sample for free, you will need to search for a site that offers these for their customers. There are so many of these sites, which can be found on the internet. All you have to do is search for the right sites which can give you the right critique analysis essay sample for free.

Are You Better at the ACT or SAT Find Out For Sure!

Are You Better at the ACT or SAT Find Out For Sure! SAT / ACT Prep Online Guides and Tips Because colleges accept both the ACT and SAT, it can be had to figure out which test to take. The changes to the SAT in 2016 made the two tests more similar than ever, although there are still some significant differences in content and format between the two tests. So how can you tell if you'll do better on the SAT or ACT? Drawing on my experience as a 99 percentile scorer on both the SAT and ACT, I'll give you a surefire way to figure out which test will result in the best outcome for you. The Gold Standard of Deciding Between the ACT and SAT There are enough differences between the ACT and the SAT that, empirically, it is difficult to predict beforehand if you'll be better at one than the other. The method I'm going to describe is the best way to be sure of seeing how you'll do on the SAT or ACT. You can use this information in many ways: to figure out what test to study, to see which scholarships you should apply to, and so forth. Once you've used this method, you don't have to guess. What's the method? It's to take both a real practice SAT and a real practice ACT. Who Should Use This Method? Taking practice tests is called the gold standard for a reason - it gives super precise information about which test you'll perform better on. However, taking two full-length practice tests is also time consuming. You should definitely use this method if one of the following applies to you: #1: You're Studying for 40+ Hours If you're going to focus on studying seriously, especially for more than 40 hours, it make sense to make sure you're spending it studying for the right test. Conversely, if you have fewer than 40 hours left (for example, only 20 hours), you should probably not spend 8 hours figuring out what test to take. #2: You're Willing to Invest Time and Energy in Studying If you care about your scores and are generally willing to invest the effort to get the best score, then taking a realistic practice SAT and a realistic practice ACT is a must. This method is not only good for telling if you're better at the ACT or SAT, but is also good practice in and of itself. If you're serious about the SAT or ACT, it would be a mistake not to do this. How Do I Find Out Whether I'm Better at the ACT or SAT? Step 1: Take a Full Practice SAT and a Full Practice ACT Get a real ACT practice test and a real SAT practice test (you can click on the links to get three of each for free). Make sure to choose one that you have not already used. Also, ideally, you should create a realistic testing environment with a timer, calculator, watch, and a quiet room. Now schedule four hours on two separate days to take the practice tests. You want to take them on separate days so that you're not more rested for one than the other. Most important of all, make sure your testing environment is similar on both days. The comparisons will not be valid if you take one at 10AM in a quiet library with plenty of sleep, and another at 8PM in a noisy house after eating a heavy meal. Step 2: Convert Your ACT Score to an SAT Score Now that you have both scores, use our ACT to SAT score conversion tools and tables to convert your ACT score to its SAT equivalent. Example: Mary got a 29 on her practice ACT. She uses the table linked above to convert this to1340. Mary got a 1200 out of 1600 on her SAT. Step 3: Compare Your Scores and Make the Call If your score difference ismore than 100 pointsin either direction, then you have a clear winner. You have done substantially better on one test than the other. You know which one you are better at! Moreover, a 100-point difference is substantial, and colleges will reward you for the better score. Continuing from the example above, Mary's ACT score is equivalent to a 1340 SAT score, while her SAT score is 1200. This means her ACT score is 140 points better than her SAT. She is definitely better at the ACT. If your score difference isless than 100 points, then you don't have a natural disadvantage on either test. The point difference is likely due to chance, and you could study for and score equally well on either test. Now you know how to precisely figure out whether you are better at the SAT or ACT! What’s Next? Get free offical practice SATs and official practice ACTs from us. Download and save them now and use them whenever! Don't have time to use the gold standard? Use our quick method to find out if you're better at the SAT or ACT. Read about the nitty gritty technical details about differences between the SAT and ACT. Want to improve your SAT score by 160 points or your ACT score by 4 points?We've written a guide for each test about the top 5 strategies you must be using to have a shot at improving your score. Download it for free now:

How Systematic Random Sampling Work

How Systematic Random Sampling Work Systematic sampling is a technique for creating a random probability sample in which each piece of data is chosen at a fixed interval for inclusion in the sample. For example, if a researcher wanted to create a systematic sample of 1,000 students at a university with an enrolled population of 10,000, he or she would choose every tenth person from a list of all students. How to Create a Systematic Sample Creating a systematic sample is rather easy. The researcher must first decide how many people out of the total population to include in the sample, keeping in mind that the larger the sample size, the more accurate, valid, and applicable the results will be. Then, the researcher will decide what the interval for sampling is, which will be the standard distance between each sampled element. This should be decided by dividing the total population by the desired sample size. In the example given above, the sampling interval is 10 because it is the result of dividing 10,000 (the total population) by 1,000 (the desired sample size). Finally, the researcher chooses an element from the list that falls below the interval, which in this case would be one of the first 10 elements within the sample, and then proceeds to select every tenth element. Advantages of Systematic Sampling Researchers like systematic sampling because it is a simple and easy technique that produces a random sample that is free from bias. It can happen that, with simple random sampling, the sample population may have clusters of elements that create bias. Systematic sampling eliminates this possibility because it ensures that each sampled element is a fixed distance apart from those that surround it. Disadvantages of Systematic Sampling When creating a systematic sample, the researcher must take care to ensure that the interval of selection does not create bias by selecting elements that share a trait. For example, it could be possible that every tenth person in a racially diverse population could be Hispanic. In such a case, the systematic sample would be biased because it would be composed of mostly (or all) Hispanic people, rather than reflecting the racial diversity of the total population. Applying Systematic Sampling Say you want to create a systematic random sample of 1,000 people from a population of 10,000. Using a list of the total population, number each person from 1 to 10,000. Then, randomly choose a number, like 4, as the number to start with. This means that the person numbered 4 would be your first selection, and then every tenth person from then on would be included in your sample. Your sample, then, would be composed of persons numbered 14, 24, 34, 44, 54, and so on down the line until you reach the person numbered 9,994. Updated by Nicki Lisa Cole, Ph.D.

Disability and education Essay Example | Topics and Well Written Essays - 1250 words

Disability and education - Essay Example The most eminent AS characteristics include, Seizures, which start showing at the age of 2 to 3 years affecting approximately 80% of all children experiencing AS (Clayton-Smith, 2010). Speech impairment, which ranges from little to no words at advanced stages. Consequently, this forces some victims end up using gestures or picture communication systems while conversing with other people (Clayton-Smith, 2010). In adult stage, people experiencing AS usually develop facial distinct features commonly described as â€Å"coarse† Victims of this disorder exhibit hyperactivity and in some cases stiff limbs, which become hindrance to their mobility. Sleep disorder. Imbalance state especially when one is walking or trying to undertake certain personal tasks. Exuberant behavior coupled with happy demeanor (Dan, 2009). b. Incidence/prevalence Studies so far contacted cite AS is among the rarest diseases not only in US but also globally. Its prevalence is about one person in every populati on ranging from 12,000 to 20,000 people (Panayiotopoulos, 2010). However, this prevalence only represents estimates because the disorder’s exact data up to date is still unknown. ... d. Etiology Angelman Syndrome (AS) is a disorder normally caused by the anomalous functioning of the UBE3A gene, located on chromosome number 15. A child inherits a copy of the gene from each parent. The two copies are active in nearly all the body tissues but only the gene replica attained from the mother is active in the brain. The disorder occurs due to four major genetic mechanisms, which include chromosome 15q11 –q13 deletion. It involves deletion of a very small piece of DNA missing from the chromosome. The number of Angelman Disorder due to deletion range from 65% to 75% and the risk of recurrence rate being 1 %(Cassidy & Allanson, 2011). The second mechanism is the paternal uniparental disomy (UPD) whereby the patient posses two copies of the chromosome 15 and no copy of the same chromosome from the mother. The number of AS cases due to UPD accounts for 3 to 5 %of all reported cases where chances of recurrence is below 1 percent. The third mechanism encompasses Imprint ing Center (IC) mutations, which account for about 7% to 9% of the reported AS cases and has a significant recurrence of 50%. The IC works like a switch. It turns on the UBE3A gene copy inherited from the mother while at the same time turns off the copy of the gene inherited from the father in the central nervous system tissues. The fourth mechanism is the UBE3A mutations. It occurs irregularly in patients suffering from it and accounts for an approximately 6% to 20% of the total AS cases. Normally, the risk of recurrence is less than 1% but increases to 50% if the mother of the affected person has the UBE3A mutation on her inherited paternal chromosome 15. However, in

Media Review Essay Example | Topics and Well Written Essays - 500 words - 1

Media Review - Essay Example ocial policy begun in 2011 through the aid of the digital internet transition who’s aim was to come up with new opportunities that have continually led the innovative forms of investigative journalism. As a result, Ai Media for the past two years have continuously embarked on diligently using the social media (Face Book, Twitter and YouTube) to reach out and share information with regard to the deaf and hearing impaired in the US community. In essence, the company focus more on the disabled persons, and how they should also be given a chance in participating in this company and the products that the company provides. In response, the company continually welcomes feedbacks and suggestions regarding such reactions and comments that are given out by all participants (Flynn 4). Of importance to note is that, Ai-Media has certain principles and guidelines that the company uses in ensuring their media policy remain an efficient tool of communication. To begin with, this social policy ensures that the concept of the community is well understood in terms of giving support to either side (clientele and the company). Secondly, contents found on the social media are friendly to the clientele and further embrace the presence of opinion diversity. This must go in line with the materials that are posted on the social media, the audience involved and the judgement that the company gives. In addition, Ai-Media is conscious and transparent of their intention. Basically, the company is sensitive on placing posts on individual clientele or organisation regarding their nationality, gender, sexual preference, disability and any other related issues. According to Flynn (4), it is worth mentioning that, the social policy must be in a position to assist the concerned persons. In this case, the Ai-Media is mainly concerned with a particular group of people –the disabled (hearing impaired and deaf) thus bringing value as would be expected. In the

Importance of Dr. Kevorkian case for Medical Ethics :: Medical Ethics Assisted Suicide Essays

Importance of Dr. Kevorkian case for Medical Ethics The Dr. Kevorkian case is important for medical ethics, because it brings up the issues of physician-assisted suicide and physician-assisted death. Physician-assisted suicide is where the doctor is assisting the patient in suicide, but the patient actually performs the act. Physician-assisted death, also known as euthanasia, is when the doctor does the act to bring about the patient’s death based on the patient’s request. This brings up the limitations of beneficence. Does a doctor have the right to end a patient’s life to relieve their suffering? We can use the principle of double effect to analyze this case. There are four criteria for an act to be ethical according to the principle of double effect (Garrett et al., 2001): 1) â€Å"The action itself must good or morally indifferent. 2) The person must intend only the good effect and not the bad effect. 3) The bad effect cannot be the means to the good effect. 4) There must be a proportionality between the good and bad effects† Killing or assisting in suicide is not a morally indifferent act. Dr. Kevorkian says, â€Å"My intent was only to relieve their suffering, an act that inevitably killed the person.† He justified his acts, because most of his patients had Lou Gehrig’s Disease and could not feed or care for themselves (Murphy, 1999). Although only the good effect was intended, the bad effect (death) was the means to the good effect. The proportionality between the good and bad effect must be analyzed for each specific case. Dr. Kevorkian’s acts violated at least two of the principles of double effect, so they are not ethically justified. Importance of Dr. Kevorkian case for Professional Standards A profession involves the following elements (Garrett et al., 2001): 1) â€Å"a dedication to a particular way-of-life, supportive of a particular expertise 2) a deep involvement in activities important to the function of society