CASE TEACHING NOTES for “A Strange Fish Indeed: The ‘Discovery’ of a Living Fossil” by Robert H. Grant, School for Professional Studies, Saint Louis University INTRODUCTION / BACKGROUND Th is case study was developed very soon after the death of Marjorie Courtenay-Latimer (–) in May of . My hope is that it serves, in part, as a tribute to the legacy of her contributions to science. Th e case study was developed for use in an introductory freshman biology course. In this setting, it could be used as a general introduction to the nature/methods of scientifi c inquiry at the very start of a semester or later in the semester as an introduction to the topic of evolution. Additionally, this case could be modifi ed for use in a number of upper-level biology courses such as ichthyology (as a springboard into a discussion of ancient fi sh lineages or fi sh evolution), evolutionary biology (as an introduction to evolutionary relationships between classes of animals), or conservation ecology (as an illustration of the issues involved in studying rare animal species). Th e case features photographs as well as fi ctitious diary entries interspersed with actual quotations from Marjorie Courtenay-Latimer’s writings to recreate the events surrounding Courtenay-Latimer’s ground breaking “discovery” of a living (non-fossil) coelacanth (Latimeria chalumnae ) in . Th e case follows a progressive disclosure format with students receiving diary entries in two parts. Part I comprises a single diary entry that describes the day on which Courtenay-Latimer collected the fi rst coelacanth specimen as well as a handout (Handout I) with a picture of what the fi sh would have looked like when Courtenay-Latimer fi rst caught a glimpse of it in a pile of sharks, seaweed, starfi sh, sponges, and other fi sh on the deck of the Nerine. Part II is a collection of diary entries that chronicle communications between Courtenay-Latimer and her colleagues over the course of the next month and a half in her attempt to bring attention to her discovery. After each of these two parts, discussion questions are included. In the concluding part (Part III), students are given a list of facts and two additional handouts (Handouts II and III) that can be used in a number of ways to bring closure to the case depending on the instructor’s particular interest (see “Classroom Management” below for one approach). Objectives • To expose students to an incident of scientifi c discovery • To introduce students to methods of formal scientifi c inquiry • To initiate discussion concerning communication within the scientifi c community • To illustrate evolutionary relationships between classes of animals • To understand the concept of homology and to cite examples of homologous structures CLASSROOM MANAGEMENT Before the start of this case, arrange students into small discussion groups of three to fi ve. Th is can be done randomly or non-randomly depending upon the instructor’s knowledge of group dynamics, student learning styles, or communication styles within the classroom. Th e case requires no outside preparatory work by the students, and can be presented and discussed within a - to -minute class period. CASE TEACHING NOTES for “A Strange Fish Indeed” by Robert H. Grant Page 1 Start the case by handing out Part I along with Handout I, giving the students to minutes to individually read the diary entry and discussion questions and peruse the photograph on Handout I. Th en, give groups fi ve to minutes to discuss their answers to the discussion questions, fi rst in their groups and then as a class, with the instructor (or students) recording the answers and observations on the board. Next, hand out Part II and give the students another to minutes to read the diary entries and discussion questions. Again, allow fi ve to minutes for discussion of answers to questions, compiling and elaborating on answers as you go. End the case by distributing Part III and Handouts II and III. I suggest reading the list of follow-up facts as a class so that you may steer the discussion in the desired direction (evolution, conservation, etc.). Handout II is included to illustrate an overview of vertebrate evolution and to highlight the position of the coelacanth and its evolutionary relatives (i.e., Eusthenopteron ) in this tree. In this vein, Handout II facilitates understanding that the discovery of a living coelacanth was a major scientifi c discovery from the perspective not only of evolutionary biologists, but for the human species as well. (Here the instructor should stress that what was found that day by Marjorie Courtenay-Latimer was not merely a fi sh, but a living example of one of our most distant evolutionary relatives.) Handout III goes further to provide an image of a fossil coelacanth in which students can note actual anatomical features of the skeleton (in particular pectoral, pelvic, and caudal fi n bone structure). Additionally, Handout III includes a recent photograph of a living coelacanth. Th is picture can be used as a segue into a discussion of ecological/biological issues surrounding the coelacanth such as overfi shing, conservation, basic behavioral study, etc. You might even assign your students a small take-home project that involves researching at some greater depth the current status of global coelacanth populations, the evolutionary history of fi shes, or any other issues pertinent to the case. BLOCKS OF ANALYSIS Use of this case can lead to discussions of several diff erent topics, ranging from the scientifi c method to evolution to the historical role of women in science. Topics emphasized depend upon the educational goals of the instructor and the context in which the case is presented. Coelacanths belong to Class Sarcopterygii. Other members of this class include both African and South American lungfi shes (Subclass Dipnoi) and four-legged terrestrial vertebrates (Subclass Tetrapoda). While taxonomic classifi cation of these fi shes is in a state of perpetual fl ux, instructors should stress the evolutionary relationships of these groupings rather than the specifi c assignment of class or subclass to a particular group. Th e history of the coelacanth is useful knowledge to have before presenting this case. Coelacanths are thought to have arisen in the early Devonian Epoch. Around species of fossil coelacanths are known, most of which are thought to have gone extinct by the end of the Cretaceous. Fossil coelacanths have been found on every continent except for Antarctica, with the majority of these species occurring in fresh water. Close cousin to the coelacanth, Eusthenopteron, is the fossil fi sh species once cited as an intermediate form linking fi sh to amphibian species. Eusthenopteron and coelacanths share many anatomical features, the most important being the lobed fi ns that were thought to be the precursors to arms and legs in terrestrial organisms. As with the taxonomic classifi cation of coelacanths, evolutionary relationships between coelacanths, Eusthenopteron, and modern tetrapods is also under constant debate and revision. Currently in favor are theories that name fossil species such as Icthyostega and Panderichthyes as the most immediate ancestors of tetrapods. Regardless of this theoretical fl uctuation, studying coelacanths can help students learn about intermediate forms in the evolution and the appearance of new classes, families, and species. CASE TEACHING NOTES for “A Strange Fish Indeed” by Robert H. Grant Page 2 Aside from learning about evolution through the study of coelacanths, the case provides students with a window into the scientifi c method and the nature of scientifi c discovery. Instructors should stress the fact that Ms. Courtenay-Latimer was not a trained fi sh biologist and that she very carefully researched her fi nd and contacted pertinent authorities to obtain information. Also to be stressed is the fact that rather than an intimate knowledge of fi sh biology leading to her discovery, it was curiosity, an observant eye, and a good general sense of biology that led Ms. Courtenay-Latimer to her discovery. Th is is often the case with scientifi c discovery, and students will benefi t by hearing about the “layman’s” role in science. Another issue surrounding the coelacanth that others may fi nd of use in their classrooms is conservation. Class discussion could be steered towards the ethics involved with collecting and studying potentially endangered species. Questions found at the end of Parts I and II facilitate discussion of this issue. Finally, an issue brought up in the discussion questions that bears elaboration is the fact that the coelacanth was only “discovered” as defi ned by western science. As is the case with many scientifi c (and especially biological/species) discoveries, native peoples inhabiting areas in which the discoveries are made are often already familiar with the phenomenon. Depending upon the specifi c instructor’s goals, time may be spent upon alerting students to this culture-centric reality. Please see the websites listed in the “References” section below for good background material concerning virtually all aspects of coelacanths and their discovery by western science. ANSWER KEY Answers to the questions posed in the case study are provided in a separate answer key to the case. Th ose answers are password-protected. To access the answers for this case, go to the key. You will be prompted for a username and password. If you have not yet registered with us, you can see whether you are eligible for an account by reviewing our password policy and then apply online or write to [email protected]. REFERENCES Coelacanth Rescue Mission: http://www.dinofi sh.com/ Australian Museum Online: http://www.austmus.gov.au/fi shes/fi shfacts/fi sh/coela.htm iucn—Th e World Conservation Union: http://www.iucn.org/ Th e Coelacanth: http://sacoast.uwc.ac.za/education/resources/fi shyfacts/coelacanth.htm FURTHER READING Courtenay-Latimer, M.