GEOMICROBIOLOGY: AN ESSENTIAL TEACHING TOOL FOR GAEMP
Students have good backgrounds in traditional STEM subject areas, but have had no, or limited, exposure to geology and geophysics. Two examples of the bridge are described, primarily from the student's point of view; others will be discussed. Students are familiar with the role that DNA plays in tracing the lineages of living organisms on Earth. Students are also aware that microbes, as the simplest and earliest traceable forms of life, are encoded with the same information in their DNA as modern life forms. In this way, microbes link the past with the present, and also partially help to predict the future. From this basic understanding, it is easy to establish a logical sequence for instruction and discussion of the evolution of life through geologic time.
Geomicrobiology principles serve as an excellent reference point for teaching students about surficial geologic processes. The roles of microbes in concentration, dispersion, and fractionation of elemental species become more apparent when presented in reference to familiar experiments. Applied approaches are taught, such as aqueous geochemistry field methods, to show that microbes can alter the pH and other parameters of their environment. This knowledge permits the student to visualize the broader impact of microbes to rock and mineral assemblages present in different earth environments. The selective use of N- and P-rich silicates as growth substrates is understood more readily because of the students' prior familiarity of the role of nutrients, and students come away with an appreciation that natural materials are a source of life-sustaining elements. An understanding of geomicrobiology helps to inform students of the genetic relationships to other living organisms that roamed the earth before us, and of the role microbes had shaping the earth.
GAEMP is supported by NSF-OEDG award GEO-0303138.