By: Bryce Taylor, Alexa Warwick, and Ryan Skophammer
Hi BEACONites! We are Ryan Skophammer of the Westridge School for Girls, Bryce Taylor of University of Washington, and Alexa Warwick of Michigan State University. We’ve been collaborating on a BEACON-funded grant to expand options for introductory Biology teachers who want to use labs that teach concepts in evolution. Specifically, we have developed a standards-based, hands-on, long-term yeast evolution project (‘yEvo’). Ryan has been developing lesson plans and teaching the lab in his AP biology class, Bryce is providing experimental support and data analysis, and Alexa is evaluating the impact of participation on student learning.
The yeast evolution project begins by having students choose a favorite color of yeast from a living ‘palette’ of S. cerevisiae strains that have been engineered to express vibrant pigments (courtesy of the Boeke lab at NYU). Over several weeks students grow their yeast in the presence of an over-the-counter antifungal agent to select for mutants with higher tolerance. Classes at Westridge run for 80 minutes on an alternating block schedule. This means students attended AP Biology every other school day. At the beginning of each block, students inspected their experiments and transfer from a saturated culture to fresh media using a disposable sterile swab.
After a few weeks, students purify a single clone from the culture and use it in a class-wide competition, in which they use the color of their yeast as a marker to determine which is “winning” in a mixed culture. Some of these clones are then sequenced by the Dunham lab at the University of Washington to determine mutations, which students analyze and research to form hypotheses about whether a given mutation is likely to be adaptive. Early results have yielded an exciting mix of mutations in genes with known roles in resistance to the active ingredient in our antifungal, which demonstrate the experiment worked, and genes that haven’t been implicated previously but seem worthy of further investigation.
In Ryan’s class, forty-five students completed the first pilot of the yeast evolution project in the 2017-18 school year. To iteratively improve the lessons and to evaluate impacts on student learning of evolution and motivation/attitudes toward science we gave a post-survey to Ryan’s students in May 2018 (17 responses). When asked what they liked about the process of growing yeast in the presence of the fungicure, most of them mentioned watching their yeast survive or evolve over time (64.7%) and determining whether to increase the concentration of the antifungal (29.4%). When analyzing sequence data from their evolved strains the students liked seeing the actual mutations (52.9%), but also found it confusing to figure out how to analyze the data (47%), suggesting more scaffolding is needed in the design of this activity to assist students with this difficulty next time. Most of the students also liked the competition aspect (82.3%), but some disliked losing (17.6%), felt rushed (11.7%), or didn’t like counting (11.7%). Most students (94.1%) reported they were willing to do the activity again because it was fun; one person was uncertain. All students agreed or strongly agreed that they enjoyed participating. We also asked students to report on their interest in becoming a biologist as a result of their participation (41.2% agreed or strongly agreed) and their interest in STEM (47% agreed or strongly disagreed).
In November of 2018, we traveled to the National Association of Biology Teachers conference in San Diego. It was the first time we’d all met in person and provided a great opportunity to catch up and plan out our next steps. Alexa and Ryan had been to the conference previously. Bryce attended for the first time, and was supported by travel funds from our BEACON grant. In addition to discussing yEvo, Alexa and Bryce presented posters on ConnectedBio (https://connectedbio.org/) and UW Genomics Salon, respectively. ConnectedBio is an NSF-funded grant project to develop curricular materials that are designed for the Next-Generation Science Standards (https://www.nextgenscience.org/) and foster integrated learning of high school genetics and evolution. The materials use the Evo-Ed cases (http://www.evo-ed.org/) as the phenomena that students explore through a series of technology-enhanced lessons as part of the collaboration between Michigan State University researchers and the Concord Consortium (https://concord.org/). Genomics Salon is an interdisciplinary discussion group at University of Washington that brings together academics and members of the broader UW community to talk about issues in science and society. Bryce shared a repository of discussion questions and resources from 2 years of meetings, which could be a good starting point for teachers interested in building lesson plans on topics we’ve covered, but who aren’t sure where to start.
Ryan led a workshop where he shared his experience designing and teaching yEvo. The teachers present had great ideas and feedback on the project that helped us to think through where to take the project next. After the workshop several teachers hung around with additional questions and feedback. Chatting with them helped us to recognize aspects that may or may not work in every school setting, which we aim to address as we further refine protocols and materials. One particularly enthusiastic participant had some fantastic ideas about future conditions or experimental setups we could try out. He’s stayed in contact since and is running yEvo in his classroom this semester!
One of Alexa’s highlights from the meeting was attending science writer Ed Yong’s talk and then going out to dinner with him. If you haven’t seen Ed’s articles in the Atlantic yet, we recommend them: https://www.theatlantic.com/author/ed-yong/. Bryce particularly enjoyed the exhibit hall. The vendors present brought a very cool mix of biology apps, games, and toys, which are a growing and fascinating component of education that play a big role in the early stages of science training, but that you don’t get to interact with often in higher-ed settings.