The project described here involved the design, implementation, and evaluation of an upper-level, undergraduate elective course for science majors. Specific course goals were to help students gain an appreciation of the interdisciplinary nature of astrobiology, understand key ideas in astrobiology, and develop the skills necessary to communicate successfully with scientists across disciplines.
Astrobiology is the study of the origin, evolution, distribution, and future of life in the universe. Within the last decade, this interdisciplinary science has become a central theme in scientific research. This exciting new science explores the connections among topics such as the search for planetary systems around other stars, the nature of habitable zones encompassing distant stars, the existence of life in extreme environments such as the hydrothermal ecosystems of Yellowstone National Park and deep sea communities surrounding hydrothermal vents, the possible extraterrestrial ecosystems on planetary objects like Mars and Europa, and the very nature of life itself through the eyes of astrobiology research. As a result of astrobiology’s truly interdisciplinary nature, colleges and universities across the nation are beginning to look toward the field as an innovative alternative to traditional biology, chemistry, geology, and astronomy courses for fulfilling science elective requirements (Offerdahl, Prather, and Slater 2002; Sauterer 2000; Staley 2003).
Project Description
We developed, implemented, and assessed a new elective course aimed at enhancing the undergraduate education of science majors using astrobiology as the theme. This course presents a unique and perhaps unexpected challenge not often faced by faculty teaching traditional undergraduate courses.
Science majors from various disciplines generally expect different things from their coursework. On the one hand, physics and astronomy majors may anticipate being assigned long and challenging problem sets or having to develop computer algorithms. Biology and geology science majors, on the other hand, often expect to memorize components of interacting systems with clear and touchstone examples in nature. Although astrobiology has elements of both, it is also unique. Moreover, our underlying philosophical goal of assisting science majors from different cultures in communicating effectively across disciplines adds a third disparate dimension—scientific communication—which is relatively uncommon in undergraduate science majors’ curricula. Consequently, our project involved the following:
- the development of an elective astrobiology survey course for students majoring in science, and
- the evaluation of the effectiveness of this astrobiology course in terms of student achievement, attitudes, and ability to communicate interdisciplinary science results.
The course was first offered in the summer of 2003. Of the students enrolled in the course, 50% were majoring in astronomy or physics (or both), 30% were biology majors, and the rest were majoring in disciplines such as chemistry, geography, and environmental science. All but one of the students were in their junior year or higher. The other student was a graduate microbiology student. The prerequisite for the course was a minimum of six science credits, which had to be from courses generally taken by science majors. There were two designers for the course, one associate professor of astronomy and one graduate student in biochemistry. The lead instructor was the graduate student whose undergraduate degree and research are deeply rooted in the field of astrobiology.
A detailed assessment demonstrates that the course successfully met its goals and is informing revisions to additional offerings of the course. Furthermore, we hope that this course will serve as a model for others who are striving to improve the nature of undergraduate science education.
Course Specifics
Listed in both the astronomy and ecology/evolutionary biology departments, our course (ASTR/ECOL 419—Astrobiology) is an upper-level science class designed with a constructivist learning philosophy coupled with an emphasis on scientific communication. In addition to enhancing students’ comprehension of the fundamental concepts and current research in astrobiology, the course instructors believe that a key skill for individuals working within the context of astrobiology is the ability to communicate field-specific findings in a manner that is easily understood by professionals whose expertise is grounded in another scientific discipline. As a result, throughout the class we emphasized the effective communication of research findings. We expected students with training in diverse scientific fields to learn and demonstrate the ability to share field-specific information in a manner that all class participants could understand; we stressed the importance of being able to properly communicate emerging results in the field of astrobiology, regardless of a student’s scientific background.
The overarching learning goals of this course were to help students:
- appreciate the interdisciplinary nature of astrobiology,
- understand the “big ideas” in astrobiology, and
- develop skills to communicate successfully with scientists across disciplines.
To best meet these goals, we structured the course as a seminar because only a limited amount of information can be learned from lecture alone, no matter how clear or entertaining the lecture (Slater and Adams 2003). Therefore, this course was designed as a series of classroom discussions that were augmented by minilectures, collaborative group activities, and student presentations of recently published research. The course content closely followed astrobiology science research goals outlined in the NASA Astrobiology Roadmap (Connell 2002) and are abbreviated in Figure 1.
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Figure 1. Summary of the NASA astrobiology roadmap.
Goal 1: Understand the nature and distribution of habitable environments in the universe.
Goal 2: Explore for past or present habitable environments, prebiotic chemistry, and signs of life elsewhere in our solar system.
Goal 3: Understand how life originated from cosmic and planetary precursors.
Goal 4: Understand how past life on Earth interacted with its changing planetary and solar system environment.
Goal 5: Understand the evolutionary mechanisms and environmental limits of life.
Goal 6: Understand the principles that will shape the future of life, both on Earth and beyond.
Goal 7: Determine how to recognize signatures of life on other worlds and on early Earth.
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This philosophy of instruction is implemented through a carefully crafted sequence of assignments that models current best pedagogical practices as well as exposes students to cutting-edge science content within the field of astrobiology. At the start of the course, students are provided with a detailed grading rubric outlining the expectations for assignments. Samples of these rubrics are provided in Figures 3 and 4.
In total, there are six main avenues in which students practice and demonstrate mastery. The course requirements are provided in Figure 2. The first requirement is that students orally present two current events. The rationale is to increase students’ awareness of current astrobiology research and to foster students’ ability to communicate interdisciplinary science concepts clearly.
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Figure 2. Class assignments and grade distribution.
Current events, presentation, and critique (10% of final grade)
- Students are responsible for finding, critiquing, and presenting two current events. During their presentations, students are expected to explain the event, provide background information when applicable, and describe its relevance to the field of astrobiology.
Homework, group activities, and in-class assignments. (20% of final grade)
- Students are responsible for completing five homework assignments demonstrating conceptual understanding, doing in-class collaborative lab activities based on key astrobiology concepts, and leading a minimum of one class discussion. They are also required to read primary literature and share the results in class.
Conceptual quizzes (10% of final grade)
- Each week students are administered a culminating quiz to assess their conceptual understanding of the material covered that week.
Journal article presentation (20% of final grade)
- Students read and present one published article from a science journal in their area of expertise. They are expected to give a 20-minute presentation outlining (1) the main points of the article, (2) its significance to astrobiology, and (3) areas for future research/work. The presentation is to be followed by a brief question-and-answer period during which students need to be able to answer questions beyond the literal-descriptive level. There is a strong emphasis on communication, and students are required to present the information in a scientifically accurate yet understandable manner such that other students with varying expertise can easily follow the research design and results.
Class participation (20% of final grade)
- Students’ final grades include a heavy emphasis on participation in daily class discussions. Students are expected to contribute to discussion in a meaningful manner that moves the discussion forward, uses as little “jargon” as possible to ensure full class participation, and fosters a positive learning environment through open-minded and respectful discussion.
Final paper (20% of final grade)
- This paper is the culminating assignment of the course. Each student reads a minimum of three related scientific articles in an area of their choice pertaining to the field of astrobiology. They each complete a five-page minimum, typed essay that summarizes and integrates the research presented in the articles. The essay includes (1) a description of the issue/research pursued; (2) how it contributes to the research outlined in the NASA Astrobiology Roadmap; (3) why the papers are considered “astrobiology research” and not just biology, geology, planetary science, or astronomy research; and (4) suggestions for extending the research.
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Throughout the course, students are also required to complete weekly or biweekly homework assignments, engage in collaborative group activities, lead class discussions, and interpret primary literature. Each assignment supports the development of students’ deep conceptual understanding of key astrobiology concepts. In addition, the requirements of these assignments closely align with the overarching course goal of developing skills to communicate science across disciplines. For instance, when it is a student’s day to lead the class discussion, he or she is assessed on:
- the ability to engage classmates in critical dialogue about the concept presented;
- the degree to which contributions are clear, precise, and at an appropriate scientific level so that everyone in the class can follow the discussion; and
- the capacity to keep the discussion focused without limiting class participation.
Furthermore, on days when primary literature is reviewed, students are assessed on their ability to communicate the scientific findings in a way that is accessible to everyone in the course, regardless of their scientific background.
Weekly quizzes composed of open-response questions assess students’ deep conceptual understanding of the scientific topics from that week. The quizzes are based heavily on the textbook and supplementary readings and emphasize those concepts most important to astrobiology. (A suggested reading list is available as Web Figure 1 at the end of this article.) The required texts for this course were Life in the Universe (Bennett, Shostak, and Jakosky 2003) and Life in the Universe: Activities Manual (Prather, Offerdahl, and Slater 2003). These texts were written primarily for introductory astrobiology courses designed for undergraduate nonscience majors, whereas our course was an upper-level science elective course for science majors. As a result, we supplemented the texts with readings from recent, refereed journal articles on astrobiology.
At times, all students were required to read the same article. At other times, individual students were assigned different articles relating to a central topic and were asked to discuss the results in class as a jigsaw assignment (Beaudrie et al. 1998; Davis 1993). In this context, the jigsaw teaching approach required different students to be responsible for mastering different concepts, who then taught each other.
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Figure 3. Assignment rubric for the final paper.
Final paper guidelines:
- Each student will read a minimum of three related scientific articles in an area of his/her choice pertaining to the field of astrobiology. After reading these articles, each student will write a five-page minimum, typed essay that summarizes the research presented in the articles. The essay must include (1) the issue/research pursued; (2) how it contributes to the research outlined in the Astrobiology Roadmap; (3) why it is considered “astrobiology research” and not just biology, geology, planetary science, or astronomy research; and (4) suggestions for future research. A complete and correct bibliographic citation must be attached, using the same format as manuscripts published in Astrobiology.
Assessment rubric for final paper (students get 0, 1, or 2 points for each of the following):
- The student provided a detailed and accurate description of the research presented in the articles. The articles were sufficiently related to one another and were rooted firmly in the discipline of astrobiology.
- The student clearly outlined how the research contributes to the goals and objectives presented in NASA’s Astrobiology Roadmap.
- The student provided solid evidence as to how the research contributes to the interdisciplinary frame of astrobiology and is not just an extension of a single scientific field.
- The student provided thoughtful, unique, and/or innovative avenues for further research.
- The bibliography is consistent with professional, published work in the field of astrobiology and is consistent with the format of the journal, Astrobiology.
- The student’s writing was of sufficient quality and professionalism and effectively communicated scientific ideas in a way that is comprehensible to scientists across disciplines.
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The final three course requirements were designed to teach students to communicate and understand scientific findings across disciplines. These assignments were journal article presentations, meaningful class participation, and a final culminating paper. Figures 3 and 4 are detailed grading rubrics that outline the expectations for the final paper and class participation. Each of these three assignments emphasizes the need for students to present appropriate scientific background knowledge to classmates trained in differing areas, to facilitate an open and risk-free learning environment, and to communicate the relevance of field-specific astrobiology research. These assignments help prepare students to work as interdisciplinary scientists.
| Figure 4. Assignment rubric for class participation.
The student’s participation level:
2— was involved but not overbearing. Student asked and responded to questions when appropriate. Student supported arguments with solid scientific evidence.
1— ebbed and flowed. Student wasn’t consistent in asking or responding to questions. Student did not consistently support arguments with solid or clear scientific evidence.
0— low or nonmeaningful. Student used anecdotal evidence to support his or her claims.
The student’s contributions to the discussion were:
2— very clear, precise, and at an appropriate scientific level so that everyone in the class could follow the discussion.
1— slightly “technical” or “jargony”; some of the class had difficulty following discussion.
0— unclear or highly technical; only a fellow scientist in the field could understand the contributions made.
The student’s contribution to a successful learning environment was:
1— appropriate. Student’s attitude was positive and encouraged the full participation of other classmates. Student listened and gave appropriate scientific feedback in discussion.
0— inappropriate. Student’s attitude was negative and tended to discourage others from participating. Student gave inappropriate feedback during discussion.
Overall, the student was:
2— extremely well-prepared. The student spent a large amount of time reading and thinking about the material before class. The student enriched the class discussion.
1— adequately prepared. The student came to class with general knowledge of the reading. The student contributed to discussion.
0— not prepared. The student did not know the material, ask appropriate questions, or provide adequate contributions. |
To help us refine future course offerings, students were asked to provide thoughtful and candid responses to a set of 10 evaluation questions upon completion of the course. Overall, their comments were overwhelmingly positive and revealed genuine satisfaction with the course. In particular, students enjoyed the course’s rigor and participatory format. Many students took this course because it enabled them to explore their own area of expertise from a new interdisciplinary standpoint. Some specifically wanted to take the course to supplement and support their understanding of the interrelatedness of the various sciences blanketed beneath the name of astrobiology. Representative questions and responses are shown in Figure 5.
| Figure 5. Examples of student evaluation comments.
Why did you enroll in Astrobiology?
- I enrolled because it relates to my Planetary Science minor, and it sounded like an interesting course to complete my credit requirements.
- Because it was an upper-division course. It appealed to me because it was new material that I had never had before and it seemed very interesting.
- I wanted to take a class in something I was interested in to broaden my horizons for Astronomy. I didn’t want to pass the class up.
What expectations did you have of the class prior to enrollment?
- To learn a new topic and find out what astrobiology was about along with what space has to offer us.
- I was expecting to get creamed with the biology part, since I hadn’t taken any classes in Bio. I was also expecting a more boring lecture format since I get a lot of those classes.
Did you enjoy the course? Why or why not?
- I enjoyed the discussions because they helped to answer questions that came up during reading or just listening to current events related to astronomy.
- I enjoyed astrobiology very much because it involves many areas of science and allowed me to learn a more broad view of life then just an introductory biology course gives. For example, I enjoyed learning about extremophiles and the potential for life on other planets.
- I thought it was great. There was lots of reading and information, but I never had a feeling of busywork, always a feeling that I could speak up. I learned a lot.
Would you recommend this course to your peers? Why or why not?
- Yes—it was a very interesting course. Teaches you a lot about what life might actually be out there.
- I would highly recommend it for anyone who wants to get in on interdisciplinary science action.
- I think having students teach areas in presentations is a good way to present material.
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In addition to student evaluations, the course instructor kept a journal in which she reflected on the class’s progress, dynamics, and nuances. (Excerpts of her journal are available as Web Figure 2 at the end of this article.) The excerpts are displayed chronologically so readers can feel the evolution of the course and her perception of students’ attitudes. In brief, the journal reveals the initial struggles in creating a community of scientific communication across disciplines. She expresses frustration at the frequent use of high-level terminology by students to describe basic science concepts, vocabulary she judges to be unnecessary. However, later reflections describe more successful interactions in the classroom. Furthermore, the instructor also describes informal interactions with the students that attest to their positive feelings about the expectations of the course related to the focus on scientific communication. These brief entries describe the building of a culture of novice scientists who possess, and even enjoy, an ability to communicate successfully across interdisciplinary chasms.
Conclusions
Seemingly unlimited in its ability to engage students, astrobiology defines itself as an interdisciplinary science at the intersection of physics, astronomy, biology, geology, and mathematics that seeks to discover where and under what conditions life can arise and exist in the universe. As a result of astro-biology’s increasing popularity, faculty at colleges and universities are considering the implementation of science elective courses in astrobiology for both undergraduate science and nonscience majors. Such courses are exciting and innovative alternatives to more traditional elective courses.
Our project focused on the development and implementation of an elective course for science majors from a cacophony of science disciplines. This course integrated the acquisition of key conceptual ideas with the practice of scientific communication across disciplines through the use of sound pedagogical methods. Such methods included the use of mini-lectures augmented with student presentations, collaborative group activities, small group discussions of primary literature, and culminating projects based in astrobiology.
Student assessments in the form of projects, quizzes, and course evaluations in combination with instructor reflections provide substantial evidence that this type of course can be a rewarding and scientifically rigorous experience for students. We plan to continue to provide this science elective course for upperclassmen. This course is a model for instructors hoping to provide an engaging and integrated experience for students.
Erika G. Offerdahl (e-mail: eofferda@email.arizona.edu) is a graduate research assistant, Edward E. Prather (e-mail: eprather@as.arizona.edu) is an assistant research scientist, and Timothy F. Slater (e-mail: tslater@as.arizona.edu) is an associate professor, all at the University of Arizona Steward Observatory, 933 N. Cherry Avenue, Tucson, AZ 85721.
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Web Figure 1. Suggested reading list.
Anderson, J. D., Schubert, G., Jacobson, R. A., Lau, E. L., Moore, W. B., & Sjorgren, W. L. (1998). Europa’s differentiated internal structure: Inferences from four Galileo encounters. Science, 281, 2019-2022.
Bennett, J., Shostak, S., & Jakosky, B. (2002). Life in the Universe. San Francisco, CA: Addison Wesley.
Chyba, C. F., & Phillips, C. B. (2001). Possible ecosystems and the search for life on Europa. Proceedings of the National Academy of Sciences of the United States of America, 98, 801-804.
Chyba, C. F., & Phillips, C. B. (2002). Europa as an abode of life. Origins of Life and Evolution of the Biosphere, 32, 47-68.
Deamer, D., Dworkin, J. P., Sandford, S. A., Bernstein, M. P., and Allamandola L. J. (2002). The first cell membranes. Astrobiology, 2(4), 371-381.
Des Marais, D. J., Harwit, M. O., Jucks, K. W., Kasting, J. F., Lin, D. N., Lunine, J. I., Scneider, J., Seager, S. Traub, W. A., & Woolf, N. J. (2002). Remote sensing of planetary properties and biosignatures on extrasolar terrestrial planets. Astrobiology, 2(2), 153-181.
Doolittle, W. F. (2000). Uprooting the tree of life. Scientific American, 282(2), 90-95.
Drake, F. D. (1961). Project Ozma. Physics Today,14(4), 40-46.
Fogg, M. J. (1998). Terraforming Mars: A review of current research. Adv. Space Res., 22(3), 415-420.
Forget, F. (1998). Habitable zone around other stars. Earth, Moon and Planets, 81, 59-72.
Forterre, P., & Philippe, H. (1999). Where is the root of the universal tree of life? Bioessays, 21, 871-879.
Gonzalez, G., & Brownlee, D. (2001). The galactic habitable zone: Galactic chemical evolution. Icarus, 152, 185-200.
Greenberg, R., Hoppa, G. V., Geissler, P., Sarid, A., & Tufts, B. R. (2002). The rotation of Europa. Celestial Mechanics and Dynamical Astronomy, 83, 35-47.
Greenberg, R. (2002). Tides and the biosphere of Europa: A liquid-water ocean beneath a thin crust of ice may offer several habitats for the evolution of life on one of Jupiter’s moons. American Scientist, 90(1), 48-56.
Hazen, R. M. (2001). Life’s rocky start. Scientific American, 284(4), 77-85.
Kasting, J. F. (1993). Earth’s early atmosphere. Science, 259, 920-926.
Kuznets, L. H., & Gan, D. C. (2002). On the existence and stability of liquid water on the surface of Mars today. Astrobiology, 2(2), 183-195.
Lazcano, A. & Miller, S. L. (1996). The origin and early evolution of life: Prebiotic chemistry, the pre-RNA world, and time. Cell, 85, 793-798.
Lissauer, J. J. (1999). How common are habitable planets? Nature, 402, C11-C14.
Lissauer, J. J. (2002). Extrasolar planets. Nature, 419, 355-358.
O’Brien, D. P., Geissler, P., & Greenberg, R. (2002). A melt-through model for chaos formation on Europa. Icarus, 156, 152-161.
Olsen, G. J., & Woese, C. R. (1997). Archaeal genomics: An overview. Cell, 89, 991-994.
Orgel, L. E. (1994). The origin of life on the Earth. Scientific American, 271(4), 77-83.
Pierazzo, E., & Chyba, C. F. (2002). Cometary delivery of biogenic elements to Europa. Icarus, 157, 120-127.
Prather, E., Offerdahl, E., & Slater, T. (2003). Life in the Universe: Activities Manual. San Francisco, CA: Addison Wesley.
Rummel, J. D. (2000). Implementing planetary protection requirements for sample return missions. Adv. Space Res., 26(12), 1893-1899.
Schindler, T. L., & Kasting, J. F. (2000). Synthetic spectra of simulated terrestrial atmospheres containing possible biomarker gases. Icarus, 145, 262-271.
Sowerby, S. J., & Petersen, G. B. (2002). Life before RNA. Astrobiology, 2(3), 231-239.
Woese, C. (2000). Interpreting the universal phylogenetic tree. Proceedings of the National Academy of Sciences of the United States of America, 97, 8392-8396. |
| Web Figure 2. Abridged instructor reflections.
First Week
Today was frustrating. We are still only in the beginning of the course content, but already I feel that some people are lost and confused. There is a pretty equal distribution of students in the various sciences, but this first part is mostly on the Big Bang and Solar System formation stuff. The astronomy students are using so much high level jargon that the biology students’ eyes are bulging out of their head. Tomorrow I will have to do a re-cap of the astronomy concepts that they are responsible for learning. I also need to emphasize the need to communicate ideas using less technical language. I think that the biology students can easily understand this at a higher level if we just explain some of the technical language that is often used by scientists “in the field.”
Third Week
Class discussion was outstanding today! This was the beginning of our discussions of the origin of life on Earth. Each student was assigned an article pertaining to some piece of the origins puzzle. They were expected to read the article, briefly share the results of the article in class, and then (as a class) reconstruct their collective knowledge of the story of the origins of life based on the primary literature…I was worried about this assignment, expecting the biology and geology folks to be totally into it and the astronomers to be lost in the “jargon”…They performed beautifully. Where the astronomers found confusion in their literature, the biology students stepped in and supplemented by explaining key ideas in their discipline in an accessible way. Likewise, the astronomers in the group brought interesting insights into the results of others articles.
Just After Midterm
One of the students stayed after class today to discuss some of the classes she has missed recently. She commented on the format of the class, in particular the discussions. She said that she enjoys learning the new science topics, especially biology ones since she hasn’t had much biology. She also explained that she feels comfortable in asking others to explain the ‘nitty gritty’ of the biology, even though her background is pretty basic.
Just Before Final Week
Walked with a student to class today. Felt very good about his comments. He is an astronomy student. He started telling me how cool it is that everyone is expected to communicate ideas in their own field for the “layman”. He went on to explain that his knowledge/understanding of his own field has increased as a result of having to share scientific ideas with students that aren’t trained in astronomy.
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Acknowledgments
We thank J. Bailey for her keen editing eye. Supported in part by a grant from the Howard Hughes Medical Institute of the University of Arizona.
References
Beaudrie, B., T. Slater, S. Stevenson, and D. Caditz. 1998. Teaching astronomy by internet jigsawing. Learning and Leading with Technology 26(4):28–31.
Bennett, J., S. Shostak, and B. Jakosky. 2003. Life in the Universe. San Francisco: Addison Wesley.
Connell, K. 2002. NASA Astrobiology Roadmap. Available online at astrobiology.arc.nasa.gov/roadmap.
Davis, B.G. 1993. Tools for Teaching. San Francisco, Calif.: Jossey-Bass Publishers.
Offerdahl, E.G., E.E. Prather, and T.F. Slater. 2002. Students’ pre-instructional beliefs and reasoning strategies about astrobiology concepts. Astronomy Education Review 1(2):5–27.
Prather, E., E. Offerdahl, and T. Slater. 2003. Life in the Universe: Activities Manual. San Francisco: Addison Wesley.
Sauterer, R. 2000. Astrobiology courses: A useful framework for teaching interdisciplinary science. Journal of College Science Teaching 29(4):233–234.
Slater, T.F., and J.P. Adams. 2003. Learner-Centered Astronomy: Strategies for Teaching, ASTRO 101. Upper Saddle River, N.J.: Prentice Hall.
Staley, J.T. 2003. Astrobiology, the transcendent science: The promise of astrobiology as an integrative approach for science and engineering education and research. Current Opinion in Biotechnology 14:347–354.