Evolution 2014: Day 0

I started off this year’s Evolution meeting early. The conference is — at its core —  a four-day affair. But the days leading into the “official” start on Friday evening feature larger workshops aimed at building skills. I chose to attend the Experiencing Evolution workshop. Here’s what this session promised:

Evolution is a key biological concept, but generating education materials that allow students to observe evolution in action can be daunting. Join us for a day focused on effective methods and tools for teaching evolution using labs, model organisms, and simulations. This workshop is designed for future and current faculty interested in improving undergraduate biology education and gaining resources to help students learn evolutionary concepts. The workshop includes lunch and instructional materials and is sponsored by the SSE Education Committee, BEACON, and NESCent.

This workshop was kicked off by a really inspiring talk (“Sailing the backyard Beagle — Darwin-inspired experiments for home & school”) given by Jim Costa of Western Carolina University/Highlands Biological Station. Costa argued that the yard and surrounding fields and forests of Darwin’s family home (“Down House”) in Kent, England played as important a role in developing his theory of evolution as did his adventures on the HMS Beagle. In Costa’s words, Darwin’s home provided him with a “backyard Beagle“. By providing our students with the opportunity to replicate some of Darwin’s backyard experiments, we can allow students to:

• Appreciate the history of how many of the tenets of Darwin’s evolutionary theory were discovered;
• Realize how accessible evidence for the evolutionary process can be — you don’t necessarily need fancy equipment to gather really valuable data; and
• Recognize that evidence for the evolutionary process can be found in our own backyards.

Costa described a lot of the experiments that Darwin conducted on his property, including many in collaboration with his children. These included a series of lawn experiments that explored the roles of disturbance, competition, and predation on species diversity, a number of fascinating seed dispersal experiments, work on the “behavior” of climbing and carnivorous plants, various tests illuminating cross-pollination strategies, and calculations on the earth-moving potential of earthworms.

The other keynote speaker was Susan Singer, a professor at Carleton College who also represents the National Science Foundation‘s Undergraduate Biology Education division. She talked about the need to train the next generation of STEM students through a “convergence” of different scientific fields. She also talked about funding opportunities for faculty who wish to develop the kinds of activities that required to accomplish this goal. While the information that she presented was valuable, its connection to the theme of the workshop was not as strong as the rest of the presentations.

The remainder of the workshop was dedicated to rotating participants through a series of three different activity sessions. The first I attended was presented by Julie Noor from Duke University. Entitled “Witnessing Evolution First-Hand”, she showed how some simple breeding experiments with Drosophila (fruit flies) can allow students to see the action of natural selection in a matter of weeks. This is an easy, cheap exercise that can be done in pretty much any classroom. As Noor nicely pointed out, no student who successfully completes this exercise can claim that they have not seen evolution happening, a particularly valuable experience for students who may have been exposed to anti-evolution propaganda. She also showed how a simple PCR/gel electrophoresis experiment conducted after the breeding experiment can allow students to see how genetic distance and recombination impact the frequency and correlation of multiple gene loci. While not as low-tech as the breeding experiment — you need to have access to a thermal cycler and gel equipment to do this lab — this activity was also very accessible to the student in an introductory course. One of the features of both of these activities that I liked was their use of data aggregation. Student collect individual data on small populations, but with each student or pair of students collecting their own data, there is the opportunity to have a pretty big sample size. Noor modeled how students might compile that data, but I think there was also an opportunity in this activity to teach students about the value of sample size. Rather than simply aggregating data and then interpreting, I think that it would be valuable to send students on the fool’s errand of trying to reach conclusions on the basis of their small sample size alone. In most cases this would lead to a variety of conclusions, creating a discrepancy that could only be mediated by data aggregation.

The second activity session that I attended was “Evolving multicellular organisms in the high school and undergraduate classroom” presented by William Ratcliff of Georgia Tech. His work totally wowed me, both in terms of the content it covered and the sophistication of the teaching tools it presented. Along with Michael Travisano and several other collaborators, Ratcliff has completed a series of experiments that demonstrate how particular lab conditions can be used to foster the evolution of multicellularity in yeast (Ratcliff et al. 2012). Amazingly, this very important basic research has served as the inspiration for two very powerful lab activities that can be completed in the high school biology classroom (and therefore are also very workable for undergraduate courses in evolution). The first lab allows students to evolve their own “snowflake yeast” using a fairly simple serial selection regime that rewards the strains that settle most quickly to the bottom of a pipet. The second lab allows students to observe first hand — and then quantify — the role that multicellularity plays in predator avoidance, as single- and multi-celled yeast strains are dyed for identification and then fed to hungry rotifers. What’s amazing about these labs is that they allow students to observe first-hand not just selection, but multi-level selection. Both of these labs are really brilliantly documented on the Snowflake Yeast Lab site, which includes downloadable teacher’s guides, student handouts, and powerpoint presentations. Ratcliff has also utilized some pre- and post-testing data to explore how well different concepts are taught by the labs, and described how he is using this assessment data to refine these labs. Really impressive stuff!

The final activity session that I attended, “Hands-on Evolution: Teaching natural selection through tree-thinking with SimBio Virtual Labs”, was dedicated to several of SimBio‘s evolution modules. Eli Meir — who runs SimBio — introduced some of the features of these modules and then Jon Herron of the University of Washington at Seattle showed how he has used these modules to support independent student activities. I explored the possibility of using SimBio activities in my Evolution course a few years ago, and in the end decided that the labs were not valuable enough to warrant asking students to pay for them. A lot has changed since I last looked at SimBio labs: they are radically improved, especially in regards to their user interface. I was particularly impressed with the “flowers and trees” activity, which features a very flexible interface that allows students to rearrange phylogenetic trees right on the screen. This module uses what I consider the best practice for conceptual teaching in that it starts with an activity that demonstrates a concept and then challenges students with a problem that they can only solve if they have mastered the focal concept. Another really innovative and potentially-game-changing feature that SimBio is starting to incorporate into their labs is a “WordBytes” assessment questions. These questions provide a valuable compromise between seemingly-divergent assessment methods: students construct a verbal explanation of a phenomenon, but do so using preset phrase fragments, allowing an underlying algorithm to provide automated feedback. This allows students to iterate answer attempts until they get the right answer, using feedback to guide incremental improvements to their answers. Herron explained how the simulation modules in these SimBio activities can be used to support independent student inquiry, leading to research projects based on student-designed simulations. I have tried this with limited success using AVIDA-ED, and I can see how the greater diversity and potential variation provided by these SimBio modules would better support student research projects.

All these cool labs have made me want to create an “Evolution in Action” course at Pratt; I can envision this as a lab-based class aimed at students who enjoyed their ecology or evolution “core” courses. It seems like the required number of lab and simulation activities now available to support such a course are already available.

Thanks to Louise Mead and Kristin Jenkins, who organized this really powerful workshop.

The true opening of the conference was kicked off by the Stephen J. Gould Award lecture, “Snails in Art and the Art of Snails” presented by Steve Jones of University College London. Jones peppered commentary on the natural history of snails — in particular their diversity of shell-color phenotype — with examples of how snails have been portrayed in art through the ages. He also talked a bit about his own experimental work, which considers the role of habitat micro-climate in maintaining and/or reducing diversity of shell color.