Living Environment Course Outline

Here's the planned sequence of my living environment course:

Unit 1: Introduction to Mental Models, Scientific Method & Living Environment

Unit 2: Evolution: Darwin's Model

Unit 3: Principles of Reproduction & Heredity – Mendel's Model

Unit 4: Cell Biology & Homeostasis

Unit 5: Modern Synthesis & Evolution of Life on Earth

Unit 6: Ecology

Unit 7: The Future & Human Impact on the Environment

Unit 8: Human Biology & Homeostasis

Rationale:

I would like to begin the year with a unit on evolution, since I truly believe the Dobzhansky quote about biology only making sense in the light of evolution. At the same time, I know that my students do not yet have the requisite background information to appreciate how evolution happens - heredity, genes, DNA, mutations, etc. I thought about the least number of steps I would need in order to get to evolution. I decided to break up the evolution unit and do a "simple," natural selection unit before heredity & cell biology. That will require revisiting modern synthesis after cell biology. On paper this makes sense, I'm just not sure my students will be able to handle the back-and-forth nature of such an approach. 

Of course Darwin formulated his theory of natural selection knowing nothing about genetics or simple Mendelian rules of heredity. Mendel, for his part, knew nothing about the actual mechanism for passing on traits - no idea what a "gene" was. He used the term "factors," a rather vague term for some unknown entity that was responsible for carrying traits. So why then must students know what genes are before studying heredity? Why must they understand heredity before they study evolution? I suspect that time is the issue. It simply takes longer to "cover the material" if we start with observable patterns and phenomena, then work toward the unobservable mechanisms. It seems easier to work from the mechanism, since the mechanism explains the phenomenon and is ultimately necessary to understand the phenomenon. But this is the reverse of how science usually works, and leaves the teacher open to the constant whining of "Why do we need to know this?" I want to start with the big questions - How did we get here? What makes us "us?" How do our bodies work? These are questions that students are genuinely interested in, and the answers to those questions require dabbling in some areas of study that are not otherwise immediately "interesting."

So, start with big ideas that arouse curiosity, then move to the details that are necessary to understand the big ideas, revisit big ideas. That's my approach to the extent possible. Learning is and teaching should be an iterative process.

The other difficult decision was whether to finish the year with ecology or human biology. Both are heavily tested on the exam, and both offer great opportunities to revisit major themes of the course. I decided that ending with human biology would be the most enjoyable for my students.