Located at University of Pittsburgh, Pennsylvania. We developed EvolvingSTEM, an authentic in-classroom laboratory and curriculum that demonstrates concepts of natural selection, heredity, and ecological diversity through experimental evolution of a benign bacterium. Students transfer populations of Pseudomonas fluorescens growing on plastic beads for one week, which selects for biofilm formation and mutants with new, conspicuous phenotypes. In introductory high school biology classes assessed by a delayed intervention method, our curriculum produced significantly greater topical test scores than the established curriculum. Students also learn the biomedical relevance of these evolved bacterial mutants, which alter the signaling genes that commonly evolve during chronic P. aeruginosa infections of wounds and of the cystic fibrosis airway. Further, pre- and post-curriculum surveys of student motivation toward STEM-related careers revealed multiple gains in favorability, especially among young women.
Our work demonstrates that hands-on experiences with evolving bacterial populations can greatly enhance learning of key NGSS concepts and student opinions of careers in science and technology. Although the EvolvingSTEM curriculum is succeeding in ten high schools in four states, including in diverse populations like urban Pittsburgh, significant challenges and opportunities remain. Our goals include: i) greater sustainability, such that, following training, teachers can run our curriculum with modest support from our research team, ii) broader implementation in diverse learning environments, and iii) improved assessments of impacts on learning and motivation.
In addition, we have developed but not broadly implemented extensions of our core experiment to demonstrate other NGSS-HS-LS concepts (1: structure & function, 2: ecosystem interdependency, and 3: heredity). The teacher will work with us to pursue these goals of sustainability and research-based extensions of our curriculum to link the study of evolved bacterial adaptations to other NGSS competencies. Potential timeline: mid-July – mid-August
Dr. Vaughn Cooper
University of Pittsburgh
Cooper Lab website