Developing a K-12 Learning Progression for Biodiversity in Environmental Systems

1. Developing a K-12 Learning Progressionfor Biodiversity in Environmental Systems Josie Zesaguli1*, Laurel Hartley3, Courtney Schenk1, Jonathon Schramm1, Edna Tan1, Brook Wilke2, & Charles W. Anderson1 1- Department of Teacher Education, Michigan State University, 2 – Crop and Soil Science, Michigan State University, 3- Biology Department, University of Colorado – Denver. *Corresponding Author (zesagul4@msu.edu) Methods Introduction • “Biodiversity includes all organisms, species, and populations; the genetic variation among these; and all their complex assemblages of communities and ecosystems” (ESA 1997). This variation in life is valued for several key reasons, including: • Humans rely on the Earth’s biodiversity for food, shelter and medicines • Diversity at one trophic level leads to diversity in other trophic levels • Many ecosystem services (clean water, fertile soils, pest control, etc.) are enhanced by biodiversity • Diversity provides the background for evolution and succession following environmental changes • Currently, the loss of biodiversity is occurring at the fastest known rate in history, and is caused primarily by human activities. The causes of biodiversity loss include: habitat destruction, species introductions, over harvesting, pollution, climate change and community alterations. Daily, humans make decisions that impact biodiversity, and it is essential that citizens understand the implications of these decisions. Yet, biological systems are extremely complex, with many details still being discovered. To simplify this complexity, we have identified several key principles below that are responsible for the complexity we see in ecosystems, and act as a framework for developing a biodiversity learning progression. • Key Principles for the Biodiversity Learning Progression • Characteristics of Systems • Hierarchy of systems at different scales: Biodiversity exists in 3 levels: genetic diversity at the individual and population level, species diversity at the community level, ecosystem diversity. • Structure and Function: Genetic characteristics: individual genotypes, population genetic variability, community species diversity, Phenotypic structure, function, relationships, Non-living environment • Principles Constraining Processes  • Genetic continuity: Every organism inherited its genes from parents of the same species.  • Ecological Dynamics: Populations have the potential to expand exponentially, but there are multiple ecological constraints preventing exponential increase, including 1) dispersal constraints, 2) environmental constraints and 3) internal dynamics (biotic constraints). Constraints can act as selection pressures on populations. Clinical Interviews Written Assessments • Assessment Instruments: • A range of open response written items were answered by 475 students in grade 4 through high school. • Open-ended interview items were formulated requiring subjects to assemble either a ‘natural’ system (A forest) or a ‘managed’ system ( A farm), based on a selection of pictures of different animals, plants and decomposers that are found in Michigan forests and farms, respectively. The extent of probing depended on the responses given by the respondents. The interviews were conducted in 2009 by the researchers. The sessions were audio- and video-taped and later transcribed (See Website: http://edr1.educ.msu.edu/EnvironmentalLit/index.htm). • Sample: A random sample of middle and high school students (Grade 5- 10) and science teachers in Michigan participated in the study. • Analysis: Units of analysis were the students’ transcribed accounts of their assembled forest or farm. Initial analyses gave an indication of the students’ general scope of understanding of the biodiversity concepts and processes. This led to the formulation of critical key biodiversity principles, which was then used as a basis for revisiting data from both the interviews and the previous written tests. Formulated learning progression levels were validated based on students’ levels of achievements that were reflected in their responses. Exemplars of the latter are presented in Table 1 below. Results and Conclusions Upper Anchor Lower Anchor Table 1. Exemplar responses are highlighted for questions about several key biodiversity processes at multiple scales. Responses were taken from written assessments and clinical interviews. http://www.fantasticfiction.co.uk/images/x3/x19457.jpg http://s3.amazonaws.com/twitter_production/profile_images/114922619/twitter-logo-nature_normal.gif http://www.freewebs.com/nukagirl/lion%20king%201.jpg Lower anchor students take landscapes as settings, and systems and processes are described in terms of actors with needs, powers and abilities, similar to the events in “The Lion King” story. To achieve their purposes, the actors use enablers in the environment and cooperate or compete with other actors. In contrast, upper anchor accounts of biodiversity processes are guided by several key principles, including reference to genetic continuity and ecological dynamics, ultimately leading to an understanding of complex ecosystems. Intermediate levels for individual processes are still being fleshed out; accounts tend to include the idea that organisms are constrained by ecological mechanisms, but students aren’t necessarily committed to those mechanisms, often including anthropomorphizing tendencies.