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HISTORY

M

History can be used to promotea deeper understanding of

the nature of science

David W. Rudge and Er ic M. Howe

Incorporating

Science Classroominto the

any science teachers recognizethat teaching aspects of the his-tory of science helps students

learn science content and the nature of sci-ence (NOS). The use of history can poten-tially humanize science, help students refinetheir critical thinking skills, promote adeeper understanding of scientific concepts,and address common student misconceptionsthat often resemble those of past scientists(Matthews 1994). Reflecting on historical epi-sodes can, in particular, promote a deeper un-derstanding of a host of issues associated withNOS as a process (e.g., the tentative nature ofscientific conclusions). There is consensusthat history of science should be integratedinto science content instruction, but availablemodels are often sketchy when it comes todetails (Monk and Osborne 1997; Howe andRudge forthcoming). The challenge forteachers is how to effectively incorporate his-tory into the science classroom while at thesame time being mindful of the multiple con-straints that govern classroom practice.

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We have been developing an approach to the use ofhistory of science that may provide some insights forinstructors of K–12 classes. This article describes thevarious steps to the approach and includes two ex-amples—one from a classic story of evolution, and an-other from the history of sickle-cell anemia research.

Step one: Identify and prioritize objectivesLike any curriculum development project, the solutionfor how to incorporate history of science into the class-room begins with an explicit identification of the educa-tional objectives you have for both yourself and yourstudents. Common constraints include the number ofstudents, amount of time available (both preparation andtime in class), and previous background knowledge stu-dents can reasonably be expected to have. While use of ahistorical episode may potentially support multiple ob-jectives, it is not necessary to address all of them. Stu-dents do not need to be provided with a complete histori-cal interpretation of the episode, particularly if the detailsmight distract from the educational goals (Allchin 1993).

Step two: Select an episodeThe next step is to determine which episode from thehistory of science to use in the classroom. If you haveone in mind, consult the ERIC and Educational Ab-stracts databases or search the Internet to see whethersomeone has developed a lesson plan using the sameepisode. If you do not have a particular episode inmind, it may help to prioritize your objectives to de-termine which episode to use.

For instance, past experiences led us to recognize thatwe needed a unit that would directly address misconcep-tions students often have about evolution. One of us rec-ognized that misconceptions had been previously pro-posed as explanations during the early history of researchon industrial melanism in the classic case of the pepperedmoth. In this case, the choice of which misconceptionswe needed to address led us to which historical episodeto use. On another occasion we decided that we needed ascientific phenomenon that had been studied with refer-ence to multiple subdisciplines in biology. Therefore, wedeveloped a unit of study on of the history of researchinto sickle-cell anemia that incorporates biochemistry,genetics, ecology, and evolution.

Step three: Learn about the episodeWith an episode in mind, the next step is to learnenough about it to create a way for students to reasonin a manner similar, but not identical, to past scien-tists. While ideally primary sources should be con-sulted, such as original research papers, it will also beuseful to consult textbook accounts and brief summa-ries provided in history of science texts to help create aunit for your own classroom. Classroom practice

should be thought of in termsof presenting students with aphenomenon for study, elicit-ing student prior conceptionsabout this phenomenon, andusing these volunteered com-ments to motivate the activityof the day (e.g., an investigationor a discussion that might allow them to explore andevaluate their ideas). The closing class discussion canbe aimed at not only providing understanding of theconcept, but also explicitly reflecting on what this par-ticular example reveals about science as a process. Byviewing the process in terms of the educational objec-tives for the lesson, it becomes easier to make deci-sions about what historical details to omit (as extrane-ous to the overall objectives) and also what historicaldetails to simplify or otherwise modify to help stu-dents learn the science and overcome any misconcep-tions they may have.

In our evolution unit on peppered moths, we be-gin with the introduction of a mystery phenom-enon—a rapid increase in the frequency of the previ-ously uncommon dark moths in the vicinity ofmanufacturing areas shortly after the industrialrevolution in Great Britain and continental Europe.Students are provided with photos of pale and darkmoths as well as frequency maps, and prompted toconsider whether a pattern exists in the distributionof dark moths over time. Students are also asked toprovide explanations for what is happening, which inturn are used to motivate a discussion of the ideas ofpast scientists who anticipated similar views to thoseour students have shared. We then ask students toconsider how they might develop an investigationthat would allow them to choose among these theo-ries, and again, use their ideas to motivate a discus-sion of experiments actually conducted in the past.We invite students to interpret furnished results, andin particular, put themselves in the place of the pastscientists who disagreed with one another.

Readers of The Science Teacher are no doubt awareof the controversies surrounding Kettlewell’s 1950swork on peppered moths and our current understand-ing of the phenomenon of industrial melanism. Forexample, it is now known that bird predators see bet-ter in the ultraviolet region than previously suspected,so visual camouflage may not be the only importantselective factor as was originally thought. These prob-lems actually augment the potential value of discuss-ing industrial melanism because comparing the sim-plified textbook account with what is now knownabout the phenomenon promotes greater insight into ahost of issues associated with NOS (Rudge 2004).Learning about the ongoing research into the evolu-

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tion of peppered moths helps students appreciate thetentative NOS and the continual scientific quest foradditional evidence. Such readings and discussions setthe context not only for reflecting on the experimentsand theories specifically related to the phenomenon ofindustrial melanism, but also an explicit, reflective dis-cussion of the nature of experiments and theories ingeneral (Abd-El-Khalick and Lederman 2000).

Step Four: ImplementationEffective teaching by inquiry often requires substan-tial preparation. First, a problem scenario must be de-veloped that provides students with sufficient, but notoverwhelming, detail. You also need to think in ad-vance about how best to introduce the problem for theday and then scaffold learning using a set of questions

developed in advance. You must consider how stu-dents will respond, and how to modify instruction ona moment-to-moment basis depending on their re-sponses to the learning environment created. All ofthis must be done while keeping in mind the objectivesof the day, the unit, and state and national standards.

Sickle-cell anemia exampleAn illustration of our approach with reference to thesickle-cell unit (Figure 1) provides a sense of how weencourage students to explicitly reflect on variousNOS issues. After three introductory classes, stu-dents on day four are challenged to construct a pro-visional theory to account for the varying and unex-pectedly high frequencies of the allele (gene)associated with the mystery disease (sickle-cell) in

F I G U R E 1

Emphases of the sickle-cell unit.

Class

1

2

3

4

5

6

7

8

Year(s)

1910

1923

1949

late-1940sto mid-1950s

mid-1940sto mid-1950s

1952–1954

1949, 1957

Historical description

Dr. Jim Herrick first encounters and diagnosesthe mystery patient.

Using the Emmel Test (in-vitro test) to identifysicklers from nonsicklers, Drs. Taliaferro and Huckpropose the dominance model of inheritance ofthe disease from pedigree information they havecollected.

Dr. Jim Neel resolves the distinction betweenfull (homozygous) sicklers and heterozygotes byway of new pedigree information.

Hematology work in East Africa uncovers highfrequencies of carriers for the sickle-cell disease.Several initial theories are developed.

Parasitology work in East Africa also examines thedistribution of the disease malaria.

Dr. Anthony C. Allison proposes theory of hetero-zygote protection of sickle-cell carriers to themalarial parasite.

Linus Pauling elucidates the difference betweennormal and abnormal hemoglobin forms throughelectrophoresis. Dr. Vernon Ingram sequencesthe peptides of hemoglobin and determines themolecular difference between normal andmutated forms.

Class problem

Examine histology slides and cellular models toexplain symptoms of mystery patient.

Examine pedigree data developed from resultsof Emmel test.

Examine pedigree data developed from resultsof in-vitro and in-vivo tests.

Examine ethnographic and geographic data fromUganda to explain the high frequencies of sickle-cell heterozygotes.

Examine Plasmodium falciparum life cycle andpropose mechanism of inhibiting its growth anddevelopment.

Consider how malarial data affects students’ earlierexplanations for heterozygote frequencies inUganda.

Examine DNA fragments for hemoglobin proteinsfrom electrophoresis.

Review

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the country of Uganda (Figure 2, p. 56). From a pre-vious class that addressed the genetics of the disease,students tentatively concluded that the debilitatingnature of the mystery disease should effectively re-sult in the near removal of the gene that causes itfrom a population of interbreeding individuals. Assuch, when students discover the varying and highfrequencies of carriers of the disease existing in thecountry of Uganda, they recognize it as an anomalythat cries out for explanation. Working in groups, stu-dents examine evidence (ethnographic, migrational,ecological, and topographical data) that strongly sup-ports explanations that the phenomenon is likely dueto a combination of selective mutation, gene flow (in-termarriage), and racial predetermination. Each ofthese explanations were fervently proposed and de-fended by leading scientists of that time.

In the beginning of the next class that examinesevolution, students are provided supplemental datafrom hematologic work in the late 1940s that quanti-fied the presence of a related blood disease, malaria(Figure 3, p. 56). When students examine their earlierallele frequency maps in conjunction with this ma-larial data, they inevitably observe a strong and com-pelling correlation. Students are also given the re-sults from a study conducted by Anthony C. Allison(1954) in which he collected blood samples from nu-merous children throughout Uganda and comparedthe incidence and severity of malaria between chil-dren who carried the allele for the mystery diseaseand children who did not (Figure 4, p. 57). Thesepieces of supplemental data lead students to proposea new theory that heterozygotes—those who carry asingle copy of the mystery disease gene—are in factprotected against the ravages of the malarial parasite.From this, students can predict that one would ex-pect to find higher frequencies of carriers of the mys-tery disease in those areas where malaria is present inhigh numbers. This theory postulating the selectiveadvantage of sickle-cell heterozygotes is essentiallythe same as that historically put forth by Allison as aresult of his research in the area, and the now well-accepted explanation for the continuation of sickle-cell anemia genes and the relatively high prevalencein persons of African descent.

At some point while students are engaged in groupwork to make sense of the various pieces of data givento them, each group is given various “probes” to con-sider (Figure 5, p. 57). Students are asked to sharetheir ideas with one another with the understandingthat each group will participate in a subsequentwhole-class discussion about their various explana-tions to account for the data and their interpretationsof the probes. These targeted probes serve as a mainvehicle to have students both explicitly and reflec-

Working in groups,students examine

evidence that stronglysupports explanations

that the phenomenon islikely due to a

combination of selectivemutation, gene f low(intermarriage), and

racial predetermination.

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tively consider aspects of NOS because theyare given the opportunity to connect theirwork with the conceptual material of theunit to larger NOS ideas.

For example, the first probe in Figure 5invites students to indirectly consider whatis commonly referred to as the subjective(theory-laden) NOS. Students often assumethat scientists inevitably all come to similarconclusions when examining the same data(Chalmers 1999; McComas 1996). This ispartially because students commonly believescientists are definitively objective in theirwork, free from bias and prior theoreticalcommitment. During the whole-group dis-cussions about this NOS issue, teachersshould refrain from “telling” students amore contemporary perspective of subjectiveNOS. Rather, teachers facilitate students tocomment on the strengths and weaknesses ofeach other’s answers. Usually, students cometo understand that their differing explana-tions to account for the high frequencies re-sult in part because of their own disparateperspectives—correlated to their differentbackgrounds, educational experiences, andpersonal commitments that influence whatthey “see” in the data.

The second probe (Figure 5) invites stu-dents to consider how their own explana-tions may have changed between classes.This is intended to get students to think ina rudimentary way about how knowledgein science is subject to potential change ormodification. Changes in students’ expla-nation for the frequency anomaly result inpart from their ability to reconceptualizethe problem in light of the new malarialdata. Furthermore, when pressed by the in-structor to consider whether or not theirprevious explanations were “wrong” orhave no further utility (i.e., are abandoned),students often recognize that while het-erozygote protection offers better explana-tory and predictive power, aspects of theirearlier explanations are important factorsthat contribute to the genetics of the mys-tery disease. The instructor then can askstudents whether or not they believe thatsimilar processes of theory comparison oc-cur in the development of robust and long-standing scientific theories.

The main advantage of designing lessonsthat use history of science in this way is thatit is closely aligned with constructivist te-

F I G U R E 3

Distribution of malaria in Uganda, circa 1949.

F I G U R E 2

Frequencies of the sickle-cell allele in Uganda,circa 1949.

Data adapted from Herrick (1968) and Lehmann (1953).

Hyperendemic malaria

Seasonal malaria

Normally malaria-free

Pigmoid

W. Bantu

Nilotic

Hamites

E. Bantu

46% 46%13%

8%

1%

4%

3%

28%

27%

27%

14%

30%

12%

29%

25%

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F I G U R E 4

Hematological analysis of children fromUganda, circa 1949.

Data adapted from Allison (1954) and Raper (1959).

Geneticdisposition

Normal (‘+/+’)

Carrier (‘+/-’)

Total childrenExamined

247

43

% w/falciparummalaria

46

28

Parasitedensity index

5.9

4.0

nets, meaning that students use history of science toconstruct their own understanding both of the impor-tant biology concepts and of those issues related toNOS. When students are challenged to assume a prob-lem-solving role similar to that of historical scientists,the experience facilitates student ownership of theconclusions that they themselves develop. Preliminaryempirical evidence collected in connection with thesickle-cell anemia unit described here suggests theforegoing approach can indeed help students developmore sophisticated views of NOS (Howe and Rudge,forthcoming). n

David W. Rudge (e-mail: david.rudge@wmich.edu) isan assistant professor in the Biological Sciences Depart-ment at Western Michigan University, 3134 WoodHall, Kalamazoo, MI 49008-5410, and Eric M. Howe(e-mail: emhowe@assumption.edu) is a professor ofeducation at Assumption College, 500 Salisbury Street,Worcester, MA 01609.

References

Abd-El-Khalick, F., and N. Lederman. 2000. Theinfluence of history of science courses on stu-dents’ views of nature of science. Journal of Re-search in Science Teaching 37: 1057–1095.

Allchin, D. 1993. Of squid hearts and WilliamHarvey. The Science Teacher 60: 26–33.

Allison, A.C. 1954. Protection afforded by sickle-cell trait against subtertian malarial infection.British Medical Journal 1:290–294.

Chalmers, A.F. 1999. What Is This Thing CalledScience? Indianapolis: Hackett Publishing.

Herrick, A. 1968. Area Handbook for Uganda.Washington, D.C.: U.S. Government PrintingOffice.

Howe, E. 2004. Using the history of research onsickle-cell anemia to affect preservice teachers’conceptions of the nature of science. PhD diss.,Western Michigan University.

Howe, E., and D.W. Rudge. Forthcoming. Reca-pitulating the history of sickle-cell anemia re-search: Improving students’ NOS views explic-itly and reflectively. Science and Education.

Lehmann, H. 1953. Distribution of the sickle-cellgene. Eugenics Review 46:101–121.

Matthews, M.R. 1994. Science Teaching: The Roleof History and Philosophy of Science. New York:Routledge Press.

McComas, W. 1996. Ten myths of science: Reex-amining what we think we know about the na-ture of science. School Science and Mathematics96:10–16.

F I G U R E 5

Example reflective probes for the Uganda problems.

NOS issueThe subjective (theory-laden)nature of science

The tentative nature ofscience

Probe(s)Given that you all had access to the samedata, did the members of your group allcome to the same conclusion to accountfor the high frequencies of mystery diseasecarriers? Why or why not?

Has your theory to explain the anomalouslyhigh frequencies of carriers changed fromprevious classes? Why or why not? If so,what sort of things precipitated your changein theory?

Monk, M., and J. Osborne. 1997. Placing the history and philoso-phy of science on the curriculum: A model for the developmentof pedagogy. Science Education 81:405–424.

Raper, A. 1959. Further observations on sickling and malaria. Transac-tions of the Royal Society of Tropical Medicine and Hygiene 53:110–117.

Rudge, D.W. 2004. Using the history of research on industrial melan-ism to help students better appreciate the nature of science and Themystery phenomenon: Lesson plans. In Proceedings of the SeventhInternational History, Philosophy Science Teaching Group Meet-ing, ed. D. Metz, 761–811.

Rudge, D.W., and E.M. Rudge. Forthcoming. An explicit and re-flective approach to the use of history of research on sickle-cellanemia to promote understanding of the nature of science. In TheNature of Science in Science Education: Rationales and Strategies.2nd. ed. Dordrecht, The Netherlands: Kluwer Academic Pub-lishers.

For additional insight into the history of science, seethis month’s insert—an excerpt from The Story ofScience: Aristotle Leads the Way by Joy Hakim.