1. Developing a K-12 Learning Progression for 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
Introduction
Methods
“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.
Written Assessments
Clinical Interviews
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:
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
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.
Lower Anchor
Scale
Organism
Population
Community
Linking Process
Individual Adaptation
Natural Selection
Community Assembly
Invasive Species
Typical Question
Tell a story about one organism in your forest or farm. (The accounts here are specifically focused on turkeys, both domestic and wild)
Farmers often spray their crops to help prevent bugs from eating their crops. Over time, the bugs slowly become resistant to these sprays, and so the farmers have to use different sprays to protect their crops. Tell a story about how the bugs become resistant to the sprays.
What organisms would fit in your forest ? Why?
In Michigan zebra mussels have rapidly expanded … (a) Why do you think that these two species have done so well in their new environments? (b) Why do you think invasive species like these might be a problem in new ecosystems?
Level Description
Example Accounts
Upper Anchor Accounts
Organisms are part of a network of ecological and genetic relationships
The domestic turkeys are going to have more problems with disease and that kind of thing, potentially, than the wild ones. The less genetic diversity, the more problems you’re going to have, in terms of trying to keep the animals alive and that kind of thing. But sometimes diversity is something you have to give up if you’re trying to key in on certain traits, like trying to get meat that tastes a certain way. (Teacher – Middle School 2009)
Natural selection (existing genetic diversity, differential survival and reproduction)
With repeated use of the pesticide the bugs through evolution (survival of the ones that survive the spraying) produce offspring that are resistant to the pesticide (Teacher - N ).
Community structure determined by genotype, phenotype and environment interaction
Well it is a web, so the birds eat the termites; I don’t know, the lynx might eat the birds; the moose eat the trees; the voles eat anything they can get their hands on; who knows, maybe the wolves eat the lynx; and then when all these things die it all feeds the bacteria and the bugs and the insects; and then when the big predators, like let’s say a wolf dies, and they get eaten by everything else, too. [Graduate student-C.ABP, p ].
Invasive species are subject to same constraints as native species, but alter internal dynamics of system
There are no natural predators to the new organisms ... their population increases ... and the new species … disrupts the whole ecosystem. The zebra mussels and purple loosestrife are eating another animal's food source and taking over their habitat destroying the organisms that was originally part of the ecosystem. (High School –BAS 2008)
Intermediate Level Accounts
Organism adaptations are a function of ecological mechanisms, but the specific mechanism is not articulated.
Which ones do you think are maybe more susceptible to getting turkey sicknesses?
I’m not I don’t know this for sure, but I think they (domesticated animals) lose some of their immunities that they would have if they lived out in the wild because if you live in the wild you need more protection from like weather and diseases. (7th Grade – NF 2009)
Development of immunity is passed on to offspring
The bugs can become resistant [sic] to the sprays by one getting immuned to it through their bloodstream and pass it on to bug babies it has so they would all be immuned to it (9th Grade - BLE 2008).
Organisms have “needs” but are constrained by ecological dynamics to some degree
“Cactus live in dry deserty areas ... Trees need a lot of water, cactus don’t. Cactus are made in such a way that they store water in their fleshy leaves and trees can do that a little but not for long” [Law Professor-C.DHS, p. 11]
Organisms well adapted to conditions, but specific mechanisms are vague
These species must adapt well. If they could handle many different conditions well. (High School – CTW 2008)
They don’t have any natural predators.
They disrupt the food web. (High School – WWC 2008)
Lower Anchor Accounts
Organisms are actors that purposefully adapt to their environment
Which one do you think would be faster?
The wild turkeys, because they have longer legs and their bodies are thinner, and the domestic ones have really, really short legs and they’re bigger. (7th Grade – AM 2009)
Organisms develop immunity to insecticide
Probably you keep spraying them with it and keep spraying them with it, they probably get used to it and it doesn’t bother them. [6th Grade - BJW.Farm.Grade6.p.12]
Organisms belong or don’t belong in an environment based on value judgments
I put especially endangered ones because it’s good to preserve all animals that we can for future generations to be able to observe, since it’s part of  nature. We put flowers for the beauty of it. It wouldn’t look beautiful. I put mountains I guess for variety and not a plain forest (10th Grade- JZ.C, p.1).
[I put orchids in the forest] because that would look prettier (5th Grade-ET. Brenna, p. 4).
New species do or do not fit in a given environment, and ecological relationships identified only involve predation
They have no predators that can eat them since they normally are not in this environment. They take over many things and cause problems. (High School – MAT 2008)
Because they evolved to get well adapted.
Because they will eat the other species that were here before them. (High School – NDC 2008)
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.