Diatoms of North AmericaThis year, Mark Edlund and Sarah Spaulding tag-team-taught the class. Ian Bishop was awarded the Kingston Teaching Fellowship, and was joined by returning OGTAs (Original Gangster Teaching Assistants), David Burge and Elena Jovanovska.
Students and visitors came from Arkansas, Canada, Colorado, Columbia, Delaware, Iowa, Florida, Macedonia, Minnesota, South Dakota and Utah to learn the way that diatoms are. We learned many things together, like Cymatopleura solea produces cells that range in size from 250 µm to 50 µm. We investigated the relation of valve shape to size and pooled student data to ask if a single species could have such an enormous size range, with small cells less than 20% of the maximum cell size. Our class read scientific papers on the topic, including Mann's work on the C. solea life cycle (1987) and on distinct morphologic demes within the population. Based on the class investigation, we think that our population was, indeed, a single reproducing population (although we did want to determine the size of auxospores for definitive confirmation). We will make updates to the size range listed on this website.
Many students and investigators ask the question, "How many diatoms should I count for an analysis?" This year the class investigated different approaches to enumerating diatoms and how to count just enough diatoms to be able to answer their specific research questions. We evaluated the differences between fixed count and stratified counts, and the relation to species accumulation curves and counting efficiency. We found that, as expected, a stratified counting approach uncovered greater species diversity and allowing a higher effective count. Stratified counts had less error that fixed counts, for the same effort. Stratified count data, however, could not be compared with fixed count data so that using a consistent method is crucial in analysis of diatom assemblages. Our conclusions were laid out Gothic font and summarized over beer that had just been filtered through diatomite at the West O Brewery.
As a final project, each student prepared a species page for Diatoms of the US. The pages are ready to be submitted to the Editorial Review Board for evaluation - they will appear at the top of this 2014 class page as they become open to public view. David and Ian continued study of the life history of Diatoma vulgaris, preparing a manuscript based on the previous year's class results.
To Matt Fairchild, Jane Shuttleworth, Steve Hendrix and Mike Lannoo: thank you for making it all possible through your unending support of the diatom course.
