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Design and Assessment of an Introductory Geomicrobiology Design and Assessment of an Introductory Geomicrobiology Course for Non-Geology Majors B. Hernández-Machado1, Lilliam Casillas-Martínez1,2 ABSTRACT Recent discoveries about the role of microorganisms in the establishment of the geological conditions in the planet have lead to the development of courses in Geomicrobiology. Unfortunately, most courses are designed for students with a strong Geology background, which is a limitation for universities that lack such courses. To overcome this limitation at our university, we have designed a special topics course entitled Introductory Geomicrobiology that was offered for the first time to undergraduate stu- dents from the Biology, Marine Biology and Microbiology Programs. To attract non-geology majors the course included topics such as description of Early Earth ecosystems, search for geo-biological signa- tures and current approaches in the search for extra-terrestrial life forms. An active learning environ- ment was fostered throughout the course through different activities including oral reports of research papers in the subject, followed by Gallery Runs and class discussions. Our assessment strategies, both formative and summative, revealed that such presentations were an effective way to introduce students to eight main concepts of Geomicrobiology. Student performance was stronger in group discussions than individually, with Gallery Runs as the preferred class discussion technique. Overall, our assess- ment system proved that the design of the course was effective in teaching Geomicrobiology to non- geology majors. INTRODUCTION programs, this is not necessarily the case in Geomicrobiology is the study of the role that Microbiology programs. The requirement of a microbes play or have played in specific Geology course to teach Geomicrobiology geological processes (Ehrlich 2002). Although imposes an important curricular constraint to Geomicrobiology studies has been around since non-geology majors that are interested in this 1887 with the initial discoveries by Winograsdky emerging field. To overcome this barrier at the regarding H2S reduction by Beggiatoa, the field University of Puerto Rico, Humacao (UPRH) has received wider recognition in the last decade Campus, we have taken advantage of the Special due to discoveries about the influence of microbial Topics Course to offer the first Introductory activities in shaping the habitable part of our Geomicrobiology course in Puerto Rico. The planet (Des Marais 1991). Stromatolites as the design and implementation of the course was earliest geo-biological signatures and the search supported through an NSF Research in for life forms in Mars are among these important Undergraduate Institution (RUI) in discoveries that are quite appealing to students Geomicrobiology. (Des Marais 1991). As a response to this trend, new and diverse interdisciplinary programs such Research Description of the at Undergraduate as Interactive Geosciences (University of Institution (RUI) in Geomicrobiology Connecticut), Geology with Environmental The RUI in Geomicrobiology is an educational Emphasis (Miami University), Geology and initiative that is part of a Microbial Observatory Geophysics (Louisiana State University), (MO) proposal established at the Cabo Rojo Geological and Atmospheric Sciences (Iowa State salterns in Cabo Rojo, Puerto Rico. The Cabo University) and Earth and Planetary Sciences Rojo Salterns Microbial Observatory (CRSMO) is (Washington University in St. Louis) have been dedicated to identifying the microorganisms established. All of these programs share a present in the crystallizing ponds and microbial Geomicrobiology course to introduce main mats that prevail at the location. Beyond the mere concepts of the field. While a Geology course is a identification of the organisms, we study their prerequisite for the majority of the possible role in the geological transformations Geomicrobiology courses in Geology-related that take place at the locations with special interest in the microbial mats communities 1 Biology Department, CUH Station, University of Puerto Rico- Humacao, Humacao, PR 00791 (Casillas et al., 2005). Due to their colored layers 2 [email protected] and the sticky nature of the top layers, these Hernández-Machado and Casillas-Martínez - Geologic Research Using Soil Geomorphology 23 microbial mats are quite appealing to our GEOMICROBIOLOGY INTRODUCTORY undergraduate students from different COURSE backgrounds (i.e., Geology, Microbiology, Marine Student population Biology and Biology). By dissecting the mats the A total of 13 undergraduate students enrolled students are able to visualize the direct contact of in the Introductory Geomicrobiology course. microorganisms and the minerals associated to Forty-six percent of the students attending were them. We have recently reported the use of the majoring in Biology, 38% in Microbiology and microbial mats as tools for promoting active and 15% in Marine Biology. Interestingly, only one of effective learning of basics concepts in the students had taken Geology or a Geology Geomicrobiology (Ríos-Velazquez et al., 2007). In related course before (Coastal Geomorphology) this study the students attended a series of and four had never taken a Microbiology course. workshops and described the following aspects as Since no pre-requisite courses were required for the most important outcomes of their taking the course, the student population participation in the RUI program: (a) the consisted of sophomores, juniors and seniors. opportunity to study and learn about new and different sciences disciplines, (b) the use of Main concepts and learning goals of the microbial mats to integrate different science course disciplines, and (c) the capacity to work in The Introductory Geomicrobiology Course multidisciplinary teams to learn from their peers’ was designed to give students a broad overview disciplines’ backgrounds (Ríos-Velázquez et al., of major topics or concepts in the field. These 2007). topics were reduced to: In addition, to conduct research projects and • Role of microbes in geological transformations attend several workshops during the academic of our planet year, students from the RUI program also • Early Earth ecosystems and the importance of participated in summer experiences at the Marine microorganism in the establishment of life on Biology and Integrative Geosciences Departments our planet from the University of Connecticut (UConn) in • Microbial diversity of ecosystems that Avery Point. In the summers of 2003 and 2007 simulate Early Earth development students have attended intensive • Search for geological signatures in our planet Geomicrobiology workshops consisting of a week • Search for biological signatures in other of lectures and experimental work. The planets experiments conducted included microscopic • Regulations regarding possible contamination analysis of microbial mats, setting up enrichments with extra terrestrial life forms for sulfate reducers and methanogenic organisms • Survival and resistance of life forms in extra from the anoxic layers of the mats, in situ gas terrestrial simulated environments measurements and determination of oxygen • Conditions necessarily for extra terrestrial life profiles from sediments around UConn. At the end of the workshop the students were The main learning goal of the course was to responsible for presenting their findings in oral read, present and discuss recent research presentations. Further information on the investigations that cover these eight topics, so as CRSMO research and educational initiatives can to provide the students basic knowledge about the be found via the internet at the web page of the role microorganisms exerts over geological RUI program (www.uprh.edu/~salterns). transformations in our and other planets. This As mentioned, to complement these goal was met through an active learning educational efforts we offered a Special Topics environment where students discussed some of Course in Geomicrobiology to undergraduate the major geological transformation of students from the UPRH. The course was microorganisms (i.e., carbonate formation and designed to introduce students to the field of dissolution) as well as some of the methodologies Geomicrobiology using eight main topics ranging currently used to detect extraterrestrial life forms. from role of microbes in Early Earth to the search An example of the latter was a detailed of possible extraterrestrial life. In this work, we explanation of how X-Ray diffraction analysis describe the objectives, structure and assessment help discern the biogenicity of certain minerals by of this new Introductory Geomicrobiology Course their patterns. specifically designed for non-geology majors. The structure of the course was essential to help students understand these main concepts. On 24 Journal of Geoscience Education, v. 57, n. 1, January, 2009, p. 23-32 Figure 1. Summary of educational strategies used in the Introductory Geomicrobiology course of- fered to non-Geology majors. the first day the PI provided a lecture about Rico. The paper was useful to describe some Geomicrobiology and its important implications molecular tools needed to analyze the community in the Early Earth development. As four of our structure of an ecosystem. For example, we students have never taken a Microbiology course discussed techniques for DNA extraction, PCR before, in this lecture we exposed our students to amplifications, construction of genomic libraries general Microbiology concepts
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