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Teaching Interests: I
am fortunate to have found a career that allows me to work hard at things
I love. As a graduate student teaching fellow, I first discovered that
I was equally stimulated by the intellectual challenges of research and
of explication. I am therefore happy to be able to combine these activities
at institutions that value quality teaching as well as scholarship. I
enjoy teaching broadly. In addition to several courses for Biology majors
at both the introductory (Introduction to Genetics and Development, Introduction
to Experimental Biology) and advanced (Genetics, Cell Biology, Developmental Biology) levels, I have designed
and implemented several classes for non-biology majors: At Home in the Universe, a Scientific World View; Remaking Eden. I feel that my exposure to a wide spectrum of students with
diverse interests and backgrounds has significantly enriched my pedagogy.
I find that the primary challenge in teaching science, regardless of audience level, is to pique student interest in a particular phenomenon to such a point that learning about the intricacies underlying the phenomenon will be fun for them. I always try to follow Einstein's axiom, "Science should be made as simple as possible, but not simpler." Given the complex nature of biological processes, it is important to grab student interest in a topic early on, so that their curiosity will see them through difficult material. I try to accomplish this through several pedagogical practices.
First, I try to share my own wonderment about the natural world and the way that evolution by natural selection has fashioned life's processes, and in this way to forge student enthusiasm for learning.
Second, I believe it is essential to examine the multiple facets of a topic at hand. For example, in discussions of genetic recombination, I make sure that students learn about the evolutionary implications of gene mixing in addition to the consequences of this process in inheritance. This is followed by a treatment of the macromolecular machinery involved in recombination, so that students gain an appreciation for the way that this process may have evolved from earlier DNA repair mechanisms. In short, by making the connections between various sub disciplines explicit, I emphasize the centrality and relevance of a particular topic, casting the net for student interest as widely as possible.
Third, I am a tireless advocate for visualization as a learning tool for students. For example, molecular graphics are especially important in teaching current biology, because so much about the function of biological molecules can be conveyed with molecular models. I have created, with student collaboration, a WWW site for the study of macromolecular structure, The Online Macromolecular Museum: www.clunet.edu/BioDev/omm/gallery.htm. The OMM's exhibits are interactive tutorials on individual molecules in which hyper textual explanations of key biochemical features are linked to illustrative renderings of the molecule at hand. The OMM has proved to be a valuable resource for my students and is in widespread use. I've received positive feedback on the OMM from colleagues and students worldwide, and the OMM has won widespread acclaim. For a second example, I recently obtained a $500K Keck Foundation grant to enhance scientific visualization at CLU. This grant provides for, among other things, the introduction of confocal/deconvolution microscopy into our biology curriculum, allowing our students to engage in some of the eye-popping learning experiences that modern microscopy affords. Students' enthusiasm for learning about cellular structure and function is therefore greatly enhanced.
Fourth, my teaching is based on the conviction that students must learn about the process of science, and not just a body of facts. It is vital that students understand the experimental basis of concepts described in their books, so my lectures are complementary, but non-identical to their readings. My approach to a particular topic is always historical, and I attempt to show that textbook models of processes have evolved and are based on sometimes very abstract interpretations of experimental data. I like to make clear that our current understanding of the natural world was not handed down to us on golden tablets, but rather was wrung from nature by hard labor. In laboratory, students experience some of this, and I put corresponding effort into designing experiments that not only illustrate key concepts and teach scientific processes, but that are exciting for students to carry out. All of my courses have been designed with this "science as a process" philosophy in mind.
Fifth, I use information technology (IT) intensively and in varied contexts in my classes. I think that IT significantly enhances communication and collaboration between my students and me (and among students) and empowers student learning in ways not possible with conventional means. As teachers, we too often forget that the most vital activity at our institutions is not teaching, but learning, and I believe that IT is significantly improving the learning experience of our students. I use IT with three pedagogical goals in mind: 1) to improve communication and collaboration in my classes; 2) to aid my students in information discovery, and; 3) to empower students to learn using a variety of resources. I take special pride in my online course syllabi, which are intended not only to provide students with standard course information but also to serve a central resource for course materials, including online learning materials, classroom graphics, study guides, score distributions. For examples, see: www.clunet.edu/BioDev/marcey/biol_331/bio331_syl.html; www.clunet.edu/BioDev/marcey/biol_342/bio342_syl.html; www.clunet.edu/BioDev/marcey/biol485/bio485syl.htm. Because the online syllabus is a central part of students' connection with a course, they are continually in touch with the learning goals and expectations of the class. This helps greatly in maintaining student involvement.
Finally, I am firmly committed to involving my students as teachers and not just learners. As Seneca wisely wrote, "we learn while we teach." In lectures, I employ Socratic questioning frequently, having students put in their own words their understanding of a key point, and placing them in the position of explaining a concept to their peers. This not only gives me useful feedback on the class' progress, but also teaches students to "speak Biology," improving their oral communication skills. In seminars, I become a facilitator and encourage my students to take over much of the discussion. Many of my courses involve intensive projects in which students make formal presentations that are open to the public. This approach reinforces a student's sense of responsibility for his/her own education, empowers students to become young educators, and invariably increases their interest levels.
Philosophy of Science Education in Liberal Arts Setting
What is liberal learning? Perhaps a roomful of academics might debate the answer to this question for sometime, but I think most would agree that one defining feature of a liberally educated student is, in the words of Eva Brann : "…[that they have learned] how they came by the opinions they bring along, so that they may be able to choose whether to hold on to them or to change them." Or, as Malcolm Forbes once quipped, "Education's purpose is to replace an empty mind with an open one."
I hold that an essential component of opening minds is their exposure to diverse worldviews. Sadly, only a small percentage of American college graduates today have the opportunity to learn, in depth, about the worldview that sums up our current understanding of the natural world, including ourselves, after ~ 350 years of post Enlightenment science. So, in my view, an imperative for science education in a liberal arts setting is to provide students a broad scientific erudition. At Kenyon College, I developed and directed a year long, interdisciplinary science class titled "From Cosmos to Consciousness - A Scientific Worldview" to promote such knowledge. At CLU, the course has morphed into a year-long, team-taught class for honors students, "At Home in the Universe."
Biology is a very important component of such a course because the philosophical implications of modern Darwinism are under appreciated, especially in the United States. Daniel Dennett describes the effects of these implications : "[Darwinism is] … a universal acid; it eats through just about every traditional concept and leaves in its wake a revolutionized world view." Thus, modern biology presents a view of life that often contradicts notions of creation that students learn about elsewhere. For example, whereas they might have been taught that streams and rivers have been created for the sustenance of animals living nearby, a biological perspective leads to a quite opposite conclusion, that organisms living near rivers have been constructed by their genes to take advantage of riparian habitats. The breakthroughs in genome research over the past decade have provided us direct readings of the documents of evolutionary history. What these documents (plus a vast empirical fundament of prior knowledge obtained in biology and other fields) tell us is that life on earth does not bear evidence for intelligent design. These considerations often, and delightfully, lead to thought provoking discussions with open-minded students who might initially find them counterintuitive. A valuable outcome of these discussions is the realization that a scientific worldview provides a very "soulful," awe-inspiring perspective. Contemplation of the indisputable and non-metaphorical kinship of all life on earth can be a very edifying experience indeed. It is my contention that a scientific worldview can be an important component of a set of ethics that is knowledge-based, one that is infused with a deep respect for humanity and its companions on our fragile planet, and one that informs a rational approach to solving some of our most vexing problems.
Liberal education goes further than simply immersing students in a variety of worldviews, however. John Seely Brown and Paul Dugid , in arguing against large scale distance education and for maintaining the physical continuity of residential colleges and universities, posit that high quality education involves the enculturation of students as young scholars into learning communities (something that distance learning simply is not good at). This enculturation, at its best, involves students deeply in creative processes, irrespective of their chosen discipline or future career goals. In the words of the Boyer Commission on Undergraduate Education, we need to transform our educational programs from "…a culture of receivers into a culture of inquirers." I believe it is to this culture of inquiry, a true hallmark of quality liberal education, that we wish to invite our students. I enthusiastically contribute to this culture by conducting collaborative research with undergraduates, an activity that is some of the most satisfying teaching I do. The opportunities to engage small groups of students directly in the scientific enterprise and to share with them the excitement of creating new knowledge are continual sources of joy for me. These activities are the backbone of an experiential curriculum, for there is no better way to learn science than by doing science. I am proud of the accomplishments of my numerous research students, and am grateful to them for allowing me to serve as their mentor.
Research Interests: Discovering the mechanisms of developmental processes in Drosophila melanogaster has provided key insights into animal development in general, and human development in particular. For this reason, this model organism continues to play an important role in biomedical research. We are investigating aspects of head development in D. melanogaster that are relevant to the mechanisms by which tissues are partitioned into distinct developmental fields. Specifically, we wish to test the hypothesis that appropriate expression of a Protein Tyrosine Phosphatase is necessary to constrain the development of eye tissue within the eye-antennal imaginal disc, which gives rise to dorsal aspects of the adult head.
The compound eye of Drosophila melanogaster consists of about 800 ommatidia in a polar arrangement around the dorsoventral (D-V) midline. Each ommatidium consists of eight photoreceptor cells arranged in a trapezoidal fashion with two mirror-symmetric forms, a dorsal form above the D-V midline, and a ventral form below. When differentiation of the ommatidia begins within the epithelium of the third instar larval eye-antennal imaginal disc, each ommatidium is a bilaterally symmetrical cluster of photoreceptor precursors polarized in the anteroposterior axis. These precursors become polarized on the D-V axis by proto-ommatidium rotation. The establishment of polarity along the D-V axis requires the JAK-STAT signaling pathway, which is activated by a ligand encoded by unpaired (upd) ( Zeidler, et al., 1999). Hopscotch (hop) is the Drosophila ortholog of mammalian JAK (Janus Kinase), a Protein Tyrosine Kinase (PTK). Several reports suggest that JAK-STAT signaling is important in establishing the nascent ommatidial field. First, over expression of hop in developing head tissue yields profound defects, including the production of extra eyes on dorsal aspects of the adult head (Harrison, et al., 1995). Second, Notch induced expression of eyegone, a Pax transcription factor, is required to establish and organize the prospective eye field. Eyegone, in turn, induces expression of upd at the D-V midline, activating the JAK-STAT pathway over long distances in the developing eye (Chao, et al., 2004). Third, regulatory mutations of upd yield a small eye phenotype (Zeidler, et al, 1999).
The mutant defects resulting from the over expression of the hop-encoded PTK in the developing head are similar to the ectopic compound eye duplications caused by the extra eye (ee) mutation (Marcey and Stark, 1985). The ee mutation is likely caused by a P-element insertion in the Cpr gene, which encodes a P450 oxidoreductase. Adjacent to Cpr, and transcribed in the opposite direction, is the DPez gene, which encodes a Protein Tyrosine Phosphatase (PTP). The ee mutation displays several interesting features. First, the mutation is incompletely penetrant (not all flies homozygous for the mutation display a mutant phenotype). The mutation is variably expressive in that phenotypes can include duplicated antennae, bristles, or eyes. Finally, ee is conditionally dominant, meaning that heterozygotes can display the mutant phenotype. We have developed a model to explain the exotic genetic behavior of ee that posits a down regulation of the DPez-encoded PTP as a consequence of the P-element insertion into Cpr and subsequent RNAi-induced heterochromatization of the Cpr genomic region, including the DPez locus (Lovick, et al., in preparation). The DPez gene is of special interest because PTPs are known to maintain a balance of phosphorylation within cells, acting to counter PTK phosphorylation signals. The model explains the similar mutant phenotypes of the extra eye mutation and hop over expression constructs: down regulation of the DPez PTP would result in upregulation of JAK-STAT (PTK) signaling, producing ectopic fields of ommatidial development. Thus, DPez may play an important role in normal development, constraining JAK-STAT signaling to appropriate regions of imaginal disc tissue.
Genetic studies in the our lab show that a genetic upregulator of the JAK-STAT pathway, Su(var)2-10, acts to significantly increase ee penetrance. This supports the idea that elevated amounts of JAK-STAT signaling in developing head tissue can produce extra eyes. It has been shown that mutants which decrease heterochromatization, pleiohomeotic (pho) and brahma (brm), exhibit a significant suppression of ee penetrance, indicating that the level of heterochromatization may influence ee penetrance, putatively through effects on DPez expression.
Further tests of our model using genetic, molecular, and cell biological approaches are underway.
References
Chao, J.-L., et al. Localized Notch signal acts through eyg and upd to promote global growth in D. eye. Development. 2004; 131: 3839-3847
Harrison, D.A., et al. Activation of a Drosophila Janus kinase (JAK) causes hematopoietic neoplasia and developmental defects. EMBO J. 1995; 14(12): 2857-65.
Marcey, D.J. Stark, W.S. The Morphology, Physiology, and Neural Projections of Supernumerary Compound Eyes in Drosophila melanogaster. Developmental Biology. 1985; 107: 180-197.
Shuai, K. Liu, B. Regulation of JAK-STAT signaling in the immune system. Nat. Rev. Immunol. 2003; 3(11): 900-11.
Zeidler, M. P., Perrimon, N. and Strutt, D. I. Polarity determination in the D. eye: a novel role for Unpaired and JAK/STAT signaling. Genes Dev. 1999; 13: 1342-1353.
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