Alien Invasion: A Unit on Adaptation

Abstract

            Evolution is at the root of solving many of today's biggest concerns, especially when thinking of health issues.  For example, AIDS and Avian Influenza both require the understanding of evolution in order to determine the best way to prevent the spread of and even find a cure for these diseases.  Scientific literacy is also important as people must be able to read and understand what research has found in the past in order to improve upon their methods and further the knowledge gained through scientific endeavors.  Scientific literacy and evolution are thus the focus of a unit we have developed to provide an authentic environment for learning and doing science.  Students get to design their own organism, focusing on adaptation to extreme environments, represented as alien planets, based on their own research, engaging classroom lessons, and experiments they design to test adaptations on our planet.  Students get the opportunity to engage in authentic practice and modeling of scientific thought, in a subject that is typically very vocabulary heavy, leaving little room for developing actual understanding of the unifying biological theory of evolution.  The students as well as the project will be evaluated through the model they design of their organism as well as a round robin poster presentation, encompassing the environmental and evolutionary impacts on their organism.  The main goal of the unit, to develop student understanding of evolution and increase scientific literacy, will also be evaluated based on a pre and post unit exam, designed explicitly for the purpose of testing evolutionary understanding.

            In order for future scientists to further previous research, they must have the ability to build off of what scientists have already accomplished.  Because of this, scientific literacy is a subject of concern for many educators and education researchers; however, the more traditional teaching methods, that are still prevalent within schools across the nation, often present science as a list of facts to memorize instead of as a method of practice.  Biology, in this respect, may be the worst offender, as there is so much emphasis on proper use of vocabulary, that sometimes the conceptual understanding can become lost.  Evolution, more specifically, is an area where there are some of the largest misconceptions, and yet is a unifying theory of all biological sciences, including medicine.  For example, the understanding of evolution is required for the fight against diseases such as AIDS and Avian Influenza.  In a study by Bishop and Anderson (1990), understanding of evolution in college students was found to be rife with misconceptions, such as a need-driven basis for adaptation and that all individuals of a population change gradually over time, versus the population as a whole changing gradually over time.  Their prior high school biology experiences had not helped them to form proper conceptions of the theory.  The authors also found that belief and understanding were not connected, so even students who do not agree with evolution can still understand it.  What is most encouraging is that special instruction was shown to be able to improve understanding of evolution (Bishop & Anderson, 1990).

            In order to counter these misconceptions and promote scientific literacy, we have created a unique opportunity for students to look at the subject of evolution, with an emphasis on adaptation to the environment, with a creative and thought provoking project.  The students are asked to draw upon knowledge from lessons as well as personal research in order to design a new organism and how it is adapted to its environment.  Students will also get to test their assumptions about adaptation through experimentation.  This allows students to make connections within the content as well as to use their own creativity and ingenuity.   

Project Description

            In order to increase hands on learning and students' construction of their own knowledge in the biology classroom, we proposing a unit of project-based instruction in Evolution. This unit concentrates on the development of crucial science skills such as data collection and analysis, critical thinking, and research as well as increasing students' scientific literacy. Students will gain hands on experience with the mechanisms behind evolution and develop a model that represents the accumulation of physical adaptations of one organism to a stressful environment. This unit is appropriately entitled Alien Invasion, as students will choose one organism to "invade" a planet previously not inhabited by the organism.

            Each planet represents an extreme environment from earth (artic, desert, cave, thermal vents etc.). For students' organisms to be successful on the new planet, the students will need to do extensive research on what physical stresses exist for the organism on the new planet and what adaptation will allow the organism to cope with these stresses. In conjunction with their research, students will design and implement experiments that help them determine with the exact effects of physical stress on organism. For example, a student might look at the effect of extreme heat or cold on metabolism in insects or photosynthesis in plants.

            Once students determine the physical stresses and adaptations that their organism will need to survive, they will need to draw on prior knowledge to determine the nature of how these adaptation could happen. Students will construct a phylogenetic tree to model the evolution of their organism. Next students will need to demonstrate how their organism will interact with previously existing ecological community by appropriately using nutrient cycles and food webs to explain the species interactions on the planet. Lastly, students will investigate the invasiveness of their species. Students will determine if their species will out compete local species or if the species was brought back to earth would it now out compete those species found in it's native environments.

            Once the groups have completed the above aspects of the unit, they will present their research and conclusion in the form of poster and physical model of their evolved organism. Students will then present their findings in Round Robin poster sessions where each group will present to their peers and peers will serve as evaluators to the students' work. Other faculty and guest will be invited to the poster session to increase the professionalism of the sessions and to create a more realistic presentation experience. Students' projects will be an accumulation of research and scientific inquiry that will promote scientific literacy, data collection and analysis. When creating models students will be using critical thinking skills to use the data and analysis to construct realistic and plausible solutions. Lastly by formally presenting their ideas students will be developing communication skills important to the college or work environment as well as taking ownership for the knowledge that they constructed for themselves on a topic that is usually taught straight from textbooks and vocabulary lists. 

Potential Impact

            In this unit students will design and execute experiments on the effects of physical stress on species adaptations, and research relevant current science literature. This will only teach them about Evolution and Ecology, (which addresses a number of the Texas Essential Knowledge and Skills for Biology), but they will also develop valuable skills in data collection and analysis, scientific methodology, and application and interpretation of scientific data. The goal of this unit is to provide students with skills to think critically about complex theories such as Evolution.

            We expect this unit change how students approach science. Instead of seeing a list of vocabulary words, they will see science as a way of thinking or questioning the natural world. While students will work specifically on Evolution in this unit, the skills they learn will be assets in their future work or academic career. We would also except that the knowledge that they gain from these projects will be more concrete sue to the hands on nature of the project, giving students a better chance to excel of standardized test.

            This project will be taught by two teachers in all their biology classes impacting about 200 students. Also by inviting other faculty to our final poster sessions we hope to open the minds of other educators and have an impact on the school as a community. Lastly, we hope that our students will continue in science impacting other students and teachers along the way.

Evaluation Plan

            In order to assess the effectiveness of this project, we will evaluate the students using several methods.  Through a round robin poster presentation, in which they will include a creative model of their new organism and results from the experiments they designed to test adaptations, students will be given a chance to prepare and give an authentic research presentation.  It will be modeled after poster sessions that most professional research conferences have, where the students will be asked to discuss their project with peers, as well as the instructor.  Local scientists whose work is in evolution and adaptation will be asked to come to the presentation sessions as well.

            Students will also be evaluated based on their performance on two case study assignments.  These studies will ask students to take the knowledge they have gained and apply it to a study, taken from current scientific literature, where they will have to decipher data and come to some conclusion based on their understanding of adaptation and evolution.

            Lastly, students will be given a test that has been developed to evaluate student understanding of evolution.  This test, taken from a study done by Anderson et al (2002), will be given to the students both before the unit and after to evaluate the project's goal of increasing student understanding of evolution, natural selection, and adaptation.  Students will be informed beforehand that this assessment is not going to part of their grade; it is purely a tool to measure the effectiveness of this project. 

References

Budget

Office and Creative Supplies $1000

Two In-Class Computers with Microsoft Office Software: $1500

Reference Material: $500

Subscription to Scientific Journals

Subscription to Software Program Gizmo

Reference Texts

            Cactus plants

            Yucca plants

Cushion plants

Lichens

Freeze Tolerant Insects

Sun Lamps

Thermometer

            Trip to Inner Space Cavern

            Trip to Wild Basin Wilderness Preserve and McKinney Falls State Park