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Elizabeth A. Flaherty
Assistant Professor
eflaher@purdue.edu
Department of Forestry and Natural Resources
Purdue University
A Curious Mission: An Analysis of Martian Molecules 

In this case study, students play the role of a NASA scientist tasked with analyzing samples of atmosphere and soil collected on Mars as part of the Mars Curiosity Mission. The case study takes place in the future when samples of the Martian atmosphere and surface have been returned to Earth as part of the fictional Curiosity Mission 5. Students identify which elements and molecules are present in those samples and draw the structural formula of each. Next, they use that information to determine which macromolecules could be created, and compare that list to molecules believed to exist on early Earth. Finally, students make a prediction about whether life (as we know it or otherwise) could exist on Mars, and discuss possible experimental designs to test their ideas. This case was developed for an introductory level general biology course. It could also be appropriate as an early review activity in a biochemistry course.


Mini Cases on Choosing Appropriate Statistical Tests for Ecological Data 

This set of mini cases on the ecology of eastern cottontail rabbits is designed to give students practical experience using statistics in a scientific context. Given a dataset and experimental design, groups of students are asked to play the part of a wildlife management researcher to determine the results for each study. Students practice the scientific process and gain experience making hypotheses and predictions, choosing an appropriate statistical test, interpreting and displaying results, and presenting data to others. Students choose between four basic, commonly used, statistical tests (t-test, one-way ANOVA, linear regression, and Chi-square test), and justify their choices. This activity was developed for undergraduate level students and is applicable to biology courses, particularly those dealing with ecology or management. The case is designed for student groups, but could be modified into clicker questions or individual assignments.


Seeing the Forest for the Trees: Managing for Multiple Use in National Forests

This case study has for its central theme the importance of tree size in both ecology and natural resource management and is designed to introduce components of forest management and policy, the importance of ecological relationships, and the challenge of managing resources for a variety of uses. Students evaluate relevant forest policy and management and discuss the related challenges. They then use basic trigonometry to estimate tree height and board feet in three different management areas from angle measurements obtained using a clinometer. Finally they consider the importance of tree height and forest management on ecological relationships among wildlife and their habitat. The case can be used as an introduction to natural resource management and the importance of multiple use management strategies; as a review of trigonometry and the use of spreadsheet software; or as an example of how mathematical concepts and science are used in natural resource management. This case was developed for use in an introductory environmental science or wildlife management course but could also be used in an advanced science high school course.


The Mystery of the Missing Martens 

This interrupted case study introduces basic modeling to investigate a decline in an American marten population on an island in Southeast Alaska. Two summer field technicians working on a long-term field ecology project for one of their professors notice that there are fewer marten captures this year. Through discussions with their professor, conversations with a local fur trapper, and based on their own observations, they develop a plan to model the population and the potential causes of the decline to solve the mystery. Students use Excel or other database software along with life tables and introductory population ecology to investigate three potential causes of the marten population decline. This case was developed for use in an environmental science or wildlife management course but could also be used in an advanced science high school course or general ecology course. It would be beneficial for students to have some background in statistics including how to interpret R-squared values, p-values, and 95% confidence intervals.