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References Summaries

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ReferencesSummaries

NaturalSelection in a Bottle

Houle,David, and Locke Rowe. “Natural Selection in a Bottle.” TheAmerican naturalist 161.1 (2003): 50–67. Print.

Thisjournal article discusses the results obtained in an experiment onnatural selection. Tofully understand the concept of microevolutionary processes, thereare two way to acquire information. These are through studyingnatural selection in the field and conducting laboratory basedexperiments.Infield studies, an agreement that strong selection is usual has beencreated. Quantitative genetic techniques have been employed to createcomprehensive predictions on evolution. In spite of this, evaluationof those predictions has been hardly carried out due to somedifficulty. In this regard, laboratory experiments are conducted tomake strong natural selection that can be assumed. In this way,impressive responses can be observed.

Thisstudy aims to investigate the natural selection process in laboratoryscale. It is assumed that this study can give significantobservations on the connection between naturalselection and adaptation.

Alaboratory population of Drosophilamelanogasterwas used for the experiment and the selectionon the type of age reaction at its first reproduction was analyzed.Different factors such as development time, size, female fecundity,and viability of flies were analyzed using genetically identifiedstrains of this population. The experiment was done at various timesrelative to the initiation of each bottle. Results show that thesamples which start development within 30 h of the opening of thebottle were consistently able to eclose before subsequent step ismade. During this time, it is expected that samples that startsdevelopment should decrease size as it matures so that the eclosionis guaranteed by the 14-d deadline as the theory suggested. However,it was observed that there has no decrease in size. The resultsobtained deviates from the expected one. This poses a limitation onthe response to selection on age at maturity of the selectedpopulation. Based on this study, we can conclude that laboratorybased experiment can give a great opportunity in the research onnatural selection, genetic variation, and evolutionary response.

Problemsfor Natural Selection as a Mechanism

Havstad,Joyce C. “Problems for Natural Selection as a Mechanism.”Philosophy of Science 78.3 (2011): 512–523. Print.

Inthis article, natural selection as a mechanism is contested. InDarwin’s work, Origin,the author regarded natural selection as an action and not as amechanism. However, the meaning of natural selection is uncertainfrom the moment of its conceptualization. Others describe it as anagent, an algorithm, a cause, a concept, a consequence, a force, anidea, and lastly, as a mechanism. These descriptions are notsynonymous. Hence, there is an uncertainty on the meaning of naturalselection. This leads to the discussion of natural selection as amechanism.

Skipperand Millstein, as cited by Havstad (512), evaluate natural selectionand mechanism. He concludes that natural selection is not a mechanismbased on new mechanistic philosophy. On the other hand, believes theopposite. He provides his reports that attempts to explain hownatural selection becomes a mechanism.

However,there is lacking information in Barros’ work that supports hisclaim. In this reference, the author exposes those missinginformation. There are three major problems observed in Barros’work. First, it is incomplete. Second, it only described selectiveprocess and not the natural selection which is the main topic of hiswork. Lastly, it is not mechanistic. Hence, it can be deduced thatBarros’ work is not suitable to support his claim.

Thisstudy has regarded natural selection as a distinct example at theobject level, as an explicit instance at the population level, andlastly, as different selective processes acting among organisms andpopulations. The first two descriptions explain natural selection asa mechanism but the third one does not describe natural selectionmechanistically. Thus, additional attempts to characterized naturalselection as a mechanism are also improbable to achieve.

TheTrials of Life: Natural Selection and Random Drift

Walsh,Denis M., Tim Lewens, and André Ariew. “The Trials of Life:Natural Selection and Random Drift*.” Philosophy of Science69.3 (2002): 429–446. Print.

Inthis article, it is claimed that the assumed relation between naturalselection and drift is only preserved by statistical interpretations.In this regard, the dynamical conception, another interpretation ofevolutionary theory, of evolution as a theory of forces should not beconsidered. It is because selection and drift are not forces. Alsothe explanations on natural selection and drift do not call for thecauses of population level change. Alternatively, it appeals to thestructure of populations. The author discusses the inferences onnatural selection by using the statistical interpretation.

Naturalselection is considered to be a result of a statistical property of apopulation that is its deviation in fitness. This explanation,however, opposes the statistical interpretation. It might be becausedynamical and statistical interpretations of the theory of evolutionare frequently used similarly. This article aims to compare andcontrast the dynamical and statistical interpretations to furtherexplain natural selection. To solve this, the interpretation ofrandom drift is discussed before the natural selection to easierunderstand these concepts.

Usingthe statistical interpretation, drift is described as sampling error. An example of this is when a lightning strike and it might take avery small random sample of the population. There might be amisrepresentation because the traits of the random sample might beapplied to the whole population.

Onthe other hand, natural selection takes place when the comparativerate of trait varies in a population. This is a result in variationin the averagefitnessof individuals in various trait classes. This presented thestatistical interpretation of natural selection.

Driftand selection cannot be decomposed into different parts of forces. Itis because natural selection causes drift. Drift explains thedifference between actual outcome of a series of births, deaths, andreproductions and the results expected by variation in trait fitnesswhile natural selection theory explains by using the statisticalproperties of populations.

DefiningDysfunction: Natural Selection, Design, and Drawing a Line

Schwartz,Peter H. “Defining Dysfunction : Natural Selection, Design , andDrawing a Line.” 74.3 (2014): 364–385. Print.

Inthis reference, the concept of natural selection is used to draw theline between the concepts of function and dysfunction. To explainthis, the case of Mr. Smith who has been sent to the hospital due tocongestive heart failure (CHF) was considered. He underwent operationand performed well after that. However, complications are sufferedafter the last few weeks. From the time he acquired the disease, hisheart is already dysfunctional because it wasn’t able to carry outits proper function of pumping blood. This organ has crossed the linefrom being functional to being dysfunctional. But, this line has notbeen clearly identified. This line drawing process is important tostudy the biological functions.

Generally,the concept of dysfunction has not been regarded. The purpose andpossible effects that can be considered as function of an item arehighly focused. Based on scientific concepts and by using types ofexplanations where function characterization can assume valid roles,Philosophers suggest the meaning of function. The “etiologicalview” is one of the major methods in the philosophy of biology. Inthis approach, the proper function of an item is the result supportedby natural selection.

InHarmful Dysfunction Account, Wakefield state that a condition isregarded as a disorder when it leads to some brings harm ordeprivation of benefit to a person based on the standards of theculture of the person and it leads to failure of an internal systemto carry out its function. In this case, Wakefield entails that thecharacteristic was supported by natural selection. He proposes thatdysfunction is a failure of a system in the person to carry out anatural function wherein the system was designed by naturalselection.

Conclusion

Inthis portfolio, different literature sources presented topics thatrelates to natural selection. These articles give an idea on how wecan use the knowledge in natural selection to describe a concept asseen on the article defining dysfunction. It also presented thechallenges and issue in this subject like what is presented on anarticle on natural selection as a mechanism. Additionally, it showshow it relates to different concept. A way to explain and understandthe concept of natural selection through experimental laboratorysystems was offered. To make this study, extensive research isrequired. A wide range of sources are used to make fair and balanceddiscussions.

Basedfrom the discussions offered by these articles, we can conclude thatthese information are beneficial to the understanding of naturalselection. It was assessed if natural selection is a mechanism. Theresults that are observed are fully supported by other studies. However, there are information on natural selection that needs to beclarified. But, the discussions provide clarifications on differentissues regarding natural selection. Through this, we can proceed tofurther developments as it poses problems if uncertainties are notclarified. We can also conclude that the concept of natural selectionencompasses various fields or topics of study. Because of this, wecan use this concept to explain certain phenomena, and clearlyunderstand the concepts.

Suggestionsare also given to improve and contribute to the advancement ofstudies on natural selection.

WorksCited:

Havstad,Joyce C. “Problems for Natural Selection as a Mechanism.”Philosophy of Science 78.3 (2011): 512–523. Print.

Houle,David, and Locke Rowe. “Natural Selection in a Bottle.” TheAmerican naturalist 161.1 (2003): 50–67. Print.

Schwartz,Peter H. “Defining Dysfunction : Natural Selection, Design , andDrawing a Line.” 74.3 (2014): 364–385. Print.

Walsh,Denis M., Tim Lewens, and André Ariew. “The Trials of Life:Natural Selection and Random Drift*.” Philosophy of Science69.3 (2002): 429–446. Print.