Linking Evolution and Climate: Past and Present

“Life of the Past” is the survey of the development of life on Earth based on physical evidence. This course is generally taken by non-major students at Portland State University. “Life of the Past” is offered during the regular 10 week school terms, but during the summer is condensed into a four-week format. The time-oriented biological and physical evidence discussed emphasize the observable, predictable and testable nature of science. This year's offering focused on climatic changes through time, as related to biological changes observed in the fossil record. The summer course provides two field trips that are not a part of the regular 10 week offering. These trips include a one-day visit to Western Oregon where Miocene marine sedimentary and volcanic rocks are observed, and a two-day visit to Eastern Oregon where Cretaceous through Oligocene environments are studied. These trips provide opportunities to observe and discuss these time periods as well as see and collect examples of organisms that lived during those times. Here the rock and fossil records were observed in the context of biological and climatic change, providing additional and deeper context to students' cognition. Field observations, sketching, and image collection were central to this process. The final project in which each student researched an extinct organism's geologic, climatic and biological context was designed to focus on a particular piece of the global story. Students' cognition of time and change, and the influence of external factors as forcers of these changes were determined through pre- and post-tests. Results show significant improvement in students' understanding of physical and biological change and their interconnectedness, e.g. that evolution may be linked to climate change.