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Tapping into the Pulse of the History of Science with Case Studies

Douglas Allchin


Historical case studies are a vital tool for teaching:

  • scientific reasoning and skills
  • the human and cultural dimensions of science
  • perspective for scientifically informed decision-making

August 2002

History is a valuable resource for teaching the process of science more effectively.

In 1837 Darwin started his “B” notebook on Transmutation of Species, and on page 36 wrote “I think” above the first evolutionary tree. Photo: Museum of Natural History in Manhattan.

Charles Darwin, Gregor Mendel, James Watson and Francis Crick — every biology student encounters these great heroes in the course of their studies. Their discoveries are occasions to celebrate. As role models, they may even inspire careers in science. More deeply, they provide glimpses into real biology in action. Every teacher may thus consider history as a valuable resource for teaching the process of science more effectively. Students enjoy stories. Accounts of scientific discovery, in particular, are compelling. For the resourceful teacher, histories are also opportunities that are as potentially instructive as they are engaging. They are especially apt for lessons in the nature of science, now a widespread goal in science education.3,5,14

Darwin’s nose, Mendel’s luck and Watson’s play

Some odd facts account for Darwin’s voyage on the Beagle.

Consider for example, Darwin’s nose. Many textbooks portray the significance of Darwin’s voyage on the Beagle. Yet Darwin almost did not go. His passage was provided in part to provide socialty for the captain, Robert FitzRoy. FitzRoy worried that the shape of Darwin’s nose did not reflect the criteria of “sufficient energy and determination” for the trip! An amicable first meeting apparently persuaded him.4 The anecdote is amusing, yet also informative:

  • First, one can see the import of physiognomy, a practice now regarded as pseudoscience: a cautionary tale, even for today.7
  • Second, one sees how science can hinge on odd particulars of personality and chance, not just deliberate method.
  • Finally, FitzRoy’s criteria ultimately mattered to science.

For the same reason, Darwin’s social class was important. FitzRoy, due to his own status, required a companion of equal peerage. Darwin’s family background may seem incidental. But it also provided Darwin the leisure to pursue his travels — and supported his continued research once he returned. Science involves time and money. And Darwin’s many discoveries relied in part on his wealth.

Consider, too, how Mendel discerned the mathematical patterns of inheritance. Mendel reported on seven, now renowned, pairs of traits in peas: tall/short, wrinkled/smooth, etc. However, not all traits in peas show clearly dichotomous ratios of recombination — nor every pair independent assortment.

Was Mendel lucky in his choice of 7 traits?

Was Mendel lucky? Perhaps he knew more at the outset than he let on? Many presume that Mendel tested a clear hypothesis. That fits the textbook version of the scientific method, at least. But his strategy seems quite different. He apparently followed twenty-two traits, tracking various combinations, hoping patterns would emerge.8 Only a few pure-breeding forms were available commercially. Mendel worked with what he had. He searched somewhat blindly and ignored confusing results. Still, he made an important discovery.

Play contributed to the discovery of DNA’s structure.

Finally, consider James Watson and Francis Crick developing the double helix model of DNA.18 Watson’s “method” underscores the creative dimension of science, sometimes relying on unexpected events and play. Watson, following Linus Pauling, first considered a triple helix. Then he paired nucleotide bases on the outside of a backbone. Later he paired like with like. How did he finally discover the complementary pairs? He cut out cardboard templates of the bases. Then Watson played with them, like pieces of a jigsaw puzzle. Watson’s officemate pointed out that the shapes of the guanine and thymine bases were likely wrong. The revised bases, combined and turned appropriately, matched.

These three stories about great discoveries in biology, as brief as they are, offer important lessons about how science happens. Science is more complex — and more interesting! — than the method commonly profiled in textbooks. History is valuable because it portrays this richness.

Teaching how science works: Monthly case studies

Teachers should go beyond the occasional anecdote, however. To fully appreciate the many dimensions of scientific practice, students must delve into historical case studies. In case studies, students see the process of science and the context of science in concert. Appropriate questions to address in any episode include:

Case studies should address several key questions.
  • What motivated the work?
  • How did the individual encounter a particular problem or question?
  • How did the scientist collect the relevant information? How was its reliability ensured?
  • Were the claims criticized? Why?
  • How were alternative explanations addressed?
  • How was disagreement resolved?
  • How was the work funded or supported?
  • What ethical, economic, political, cultural or gendered issues may have accompanied the research?
Students learn better when immersed in the historical context.

Students learn even more vividly when immersed in the historical context. They may be invited to tackle some problems themselves: interpreting results, finding alternative explanations, designing experiments, persuading critics, assessing ethical dilemmas, etc.10 This helps them develop their own thinking skills, especially when they can compare their work to how the earlier scientists reasoned. Students may also re-enact historical debates (for example, about spontaneous generation16 or about color vision17. Reviving the uncertainty underscores the challenge of interpreting evidence before the answer is known.

Students peering virtually over the shoulders of scientists learn how they reach conclusions. Not all research follows the formula of “the scientific method” so often profiled in textbooks. Biologists use a diverse toolbox of methods. They:

Biologists use a diverse toolbox, not one “scientific method.”
  • build models
  • apply analogies
  • induce patterns
  • allow results to “self-select” themselves
  • harvest raw data for archives
  • look for statistical correlations
  • run computer simulations
  • tinker with experimental apparatus
  • test predictions derived indirectly from hypotheses

Biology now permeates personal and public decision-making, from climate change and pesticides to cloning and stem cells. Claims are supported by many methods. Teachers need to prepare individuals to interpret the available evidence and to pose relevant further questions, whatever the case.

Case studies help expose widespread myths about how science happens.

Students typically enter biology classes with notions of how science happens. They often believe romanticized depictions of extraordinary genius and rare moments of insight. They find no reason to question these widespread myths. For any biologist who toils in the lab or field, checks every control, or struggles to develop a new experimental procedure, the myths are fictions. Of course, good history can remedy such misconceptions.2 But the history itself must be well informed. Teachers should thus ensure that their own sources are reliable and complete. They should also convey historical context well.1

Case studies are best used in succession.

Every case study adds depth to a student’s knowledge of science. One episode alone is often enough to transform preconceived stereotypes of scientists, say, or of instant certainty. However, science is complex and textured. The ideal is several case studies in succession. Multiple episodes display the diversity, as well as highlight common themes. Hence, ideally, introduce at least one case study each month. Other lessons may thereby be displaced. But the trade-offs work. Anything that is learned from a book, students can learn when the occasion demands. The skills of interpreting what they read or hear from scientists cannot. Skills and perspective need modeling, practice and guidance. Teachers will find that students readily affirm the value of what they learn from historical case studies.

More lessons in the nature of science

History illustrates how scientists can err and change ideas.

Further lessons benefit those who delve even deeper into history. For example, scientific ideas change. Sometimes they reveal earlier errors. Sometimes, research is inconclusive or interpretation of results is uncertain. This, too, can be important for public policy and decision-making. Students need to learn the limits, as well as the foundations of scientific claims. Again, history is a powerful teaching tool. Episodes of conceptual change help reveal how the meaning of evidence sometimes shifts dramatically.

Consider Christiaan Eijkman and the cause of beriberi.6,10 Here, a student sees both the power and the limit of controlled experiments.

Nobel Prize-winner Christiaan Eijkman was right and wrong at the same time.
  • In the 1890s, Eijkman applied newly established germ theory and saw the disease as bacterial.

  • Through a series of accidents, he believed that he had isolated the source of the microorganism in white rice.

  • For confirmation, he coordinated a large controlled study showing how a white rice diet — and not other hygienic factors — correlated to beriberi among over one-quarter million prisoners in Java.

  • Based on his findings, diets changed and beriberi declined.

  • Eijkman had not considered, however (and his successor later showed), that the white rice was deficient in an essential nutrient (later identified as the vitamin thiamine). Eijkman even rejected the idea when first proposed!

  • He was wrong about the bacterium. He erred. Still, his achievement was significant and earned him a share in the 1929 Nobel Prize.

Cultural and gender bias can affect scientific research.

Other stories of error may convey a less noble image of science. Science is, ultimately, a human enterprise. And sometimes scientists express cultural bias. For example, in the U.S. in the 1950s, a group of researchers did not treat some syphilis patients because they wanted to study the advanced stages of their disease. They did not seek informed consent. The subjects were all Negroes. For us now, the racism that allowed the lapse in research ethics is painfully obvious.12 It shows that biologists are not immune to human prejudices just because they are scientists. Indeed, “scientific” results have even been used to support racist ideologies. Studies of intelligence — first, based on skulls, and later on IQ — typically endeavored to show that the researcher’s own “kind” was superior. The scientists mostly seemed unaware of their own errors, even while they claimed the authority of science.9

Concepts of anatomy, behavior, and nature have likewise sometimes been shaped by gendered perspectives.11,15 It is all too easy to imagine that the banner of science legitimates such studies. A scientifically literate individual is thus familiar with such cases and is prepared to analyze and critique science, especially where power and profit are at stake.

A valuable teaching tool

Conclusion: History guides students to an understanding of how science happens.

Finally, history also offers teachers tools for teaching basic content. For example, history provides one framework for student motivation. Context gives meaning to biological questions. Arranged sequentially, they can often structure curriculum.13 Students also often share preconceptions with their historical counterparts. The experience of the past offers clues about how to guide students to more sophisticated views. History thus offers more than a parade of heroic discoveries or asides for human interest. A healthy approach to science adopts history as a tool for teaching the process of science: reasoning patterns and standards of evidence, as well as their limits. History is also essential for portraying the nature of science fully, including its human and cultural dimensions. For non-scientists, in particular, history makes biology engaging and informative.

Douglas Allchin, Ph.D., is a historian and philosopher of biology at the University of Minnesota. He received his doctorate in history and philosophy of science from the University of Chicago. He currently leads the International History, Philosophy and Science Teaching Group and edits the SHiPS (Sociology, History, and Philosophy of Science) Resource Center (

Tapping into the Pulse of the History of Science with Case Studies

SHiPS Resource Center

Science teachers will find case studies, historical updates, book reviews, short stories behind common terms, links to original papers, biographies and portraits.

Women in science

Smithsonian Education

Educational content for students, families, and educators. Find teaching materials, links to hundreds of online resources, and access to the world’s largest museum complex.

Read a book: resources for teachers

1) Case studies prepared for teaching ….

  • » Hagen, Joel, Douglas Allchin & Fred Singer. 1996. Doing Biology. Glenview, IL: Harper Collins.
  • » Matyas, Marsha Lakes and Ann E. Haley-Oliphant, eds. 1997. Women Life Scientists: Past, Present and Future. Bethesda, MD: American Physiological Society.
  • » The College Board. 1999. The Spanish Flu and Its Legacy. New York, NY: College Board Publications.

2) Some good histories for case studies ….

  • » Comfort, Nathan. 2001. The Tangled Field: Barbara McClintock’s Search for the Patterns of Genetic Control. Cambridge, MA: Harvard University Press.
  • » Geison, Gerald L. 1995. The Private Life of Louis Pasteur. Princeton, NJ: Princeton University Press.
  • » Gould, Stephen J. 1981. The Mismeasure of Man. New York, NY: W.W. Norton.
  • » Hamburger, Jean. 1992. The Diary of William Harvey. New Brunswick, NJ: Rutgers University Press.
  • » Manning, Ken. 1984. Black Apollo of Science: The Life of Ernest Everett Just. Oxford University Press.
  • » Sayre, Anne. 2000. Rosalind Franklin and DNA. New York, NY: W.W. Norton.
  • » Strick, James L. 2000. Sparks of Life: Darwinism and the Victorian Debates over Spontaneous Generation. Cambridge, MA: Harvard University Press.
  • » Turner, R. Steven. 1994.In the Eye’s Mind. Vision and the HelmholtzHering Controversy. Princeton, NJ: Princeton University Press.
  • » Weiner, Jonathan. 1994. The Beak of the Finch. New York, NY: Random House.

International History, Philosophy and Science Teaching Group

Scholars meet biennially to discuss key issues and exchange ideas.

International Society for the History, Philosophy and Social Studies of Biology

Biologists collaborate with historians, philosophers and sociologists in interdisciplinary study.

Biography Maker

The Biography Maker is an online, step-by-step process for writing great biographies. Excellent tool for science students to help them write about famous scientists.

For Educators: Case Studies

  1. Allchin, Douglas. 2001. “How not to teach historical cases in science.” Journal of College Science Teaching 30(1):33-37.
  2. Allchin, Douglas. 2002 (in press). “Scientific myth-conceptions.” Science & Education.
  3. American Association for the Advancement of Science, Project 2061. 2001. Atlas of Scientific Literacy. Washington, DC: AAAS and NSTA.
  4. Browne, Janet. 1995. Charles Darwin: Voyaging. Princeton, NJ: Princeton University Press.
  5. BSCS. 1993. Developing Biological Literacy. Dubuque, IA: Kendall/Hunt.
  6. Carpenter, Kenneth J. 2000. Beriberi, White Rice and Vitamin B. Berkeley, CA: Univ. of California Press.
  7. Cordingley, Bill. 2001. In Your Face: What Facial Features Reveal about the People You Know and Love. Far Hills, NJ: New Horizon Press.
  8. Di Trocchio, F. 1991. “Mendel’s experiments: a reinterpretation.” Jrnl of the History of Biology 24:485-519.
  9. Gould, Stephen J. 1981. The Mismeasure of Man. New York, NY: W.W. Norton.
  10. Hagen, Joel, Douglas Allchin & Fred Singer. 1996. Doing Biology. Glenview, IL: Harper Collins.
  11. Haraway, Donna. 1989. Primate Visions. New York, NY: Routledge.
  12. Jones, James H. 1981. Bad Blood: The Tuskegee Syphilis Experiment. New York, NY: Free Press.
  13. Mix, Michael C., Paul Farber & Keith I. King. 1996. Biology: The Network of Life, 2nd ed. New York, NY: Harper Collins.
  14. National Research Council. 1996. National Science Education Standards. Washington, DC: National Academy Press.
  15. Schiebinger, Londa. 1993. Nature’s Body: Gender in the Making of Modern Science. Boston, MA: Beacon Press.
  16. Strick, James L. 2000. Sparks of Life: Darwinism and the Victorian Debates over Spontaneous Generation. Cambridge, MA: Harvard University Press.
  17. Turner, R. Steven. 1994. In the Eye’s Mind. Vision and the HelmholtzHering Controversy. Princeton, NJ: Princeton University Press.
  18. Watson, James D. 1964. The Double Helix. New York, NY: Atheneum.


Understanding Science