Understanding Evolution: Problem-based discussion For the instructor: Pedagogical research indicates that students learn better if they are actively engaged. The following slides require only a few minutes each and are designed to actively engage students with lecture material on the topic of evolution through discussion. Problem-based discussions are a valuable active learning technique that involves students teaching each other, thus promoting student engagement and learning. In this technique, the instructor posts a written description of a scientific problem or a diagram, table, or graph relevant to a topic under consideration. The instructor provides a list of questions that students should work to answer. Students then spend 5–10 minutes, first thinking individually about the questions in reference to the problem or figure, and then pair up and take turns explaining their answers to each other and filling gaps in each other’s knowledge. At the end of the discussion, the instructor can read aloud the questions, either verbatim or modified to be slightly different, and ask whether students are confident they could explain the issues to each other. The instructor may wish to call on students to answer individual questions, or may ask if the discussion raised any questions they would like to ask in class. This slideshow is provided by Understanding Evolution (understandingevolution.org) and is copyright 2011 by The University of California Museum of Paleontology, Berkeley, and the Regents of the University of California. Feel free to use and modify this presentation for educational purposes.

Understanding Evolution: Problem-based discussion Population genetics calculations and Hardy Weinberg 1) What are the genotype frequencies at the flower-color locus in this generation? 2) What are the allele frequencies at the flower-color locus in this generation? 3) If the individuals in this generation mate randomly, what would you expect the genotype frequencies to be in the next generation? In a particular species of plant, flower color is genetically controlled, as shown here. The red allele and white allele are codominant. In Generation 1, a population of this plant is composed of 62 red-flowered plants, 36 pink-flowered plants, and 2 white-flowered plants.

Understanding Evolution: Problem-based discussion Population genetics calculations and Hardy Weinberg 4) If the individuals in this generation mate randomly, what would you expect the allele frequencies to be in Generation 2? 5) If the resulting individuals in Generation 2 mate randomly, what would you expect the allele frequencies to be in Generation 3? 6) Is this population evolving? Why or why not?