Description

Understanding the distributions of species in nature is a driving theme in the natural sciences, one that has remained elusive for centuries. Multiple forces shape species distributions, including habitat dynamics, species’ ability to move, and interspecies interactions, but the way they contribute on their own and together remains incompletely understood. What we do know about species distributions is based predominantly on studies of large plants and animals, and processes discovered in those groups may not be the same as for other organisms. Smaller, sessile, symbiotic organisms, like lichens, remain a mystery. Their complicated reproductive biology and dispersal strategies, and obligate symbiotic relationship make understanding how various factors shape their distributions particularly challenging. In this CURE students will develop hypotheses, generate large-scale trait datasets from digitized herbarium specimens of lichens, and analyze their datasets to determine how lichen traits may influence their distributions.

Intended Audience: Undergraduate students at all levels, may be modified for advanced high school students.

Learning Time: Flexible, 3-6 weeks.

Required Resources: Access to a computer and internet connection. QGIS, JASP, and Google Sheets are used in the tutorials, all of which are freely available online. No physical laboratory resources are required. 

Learning Objectives

By engaging in this project students will:

• Develop hypotheses regarding the relationship of reproductive biology with evolutionary and/or ecological processes,
• Create a morphological trait dataset using digitized herbarium specimens,
• Summarize, visualize, and analyze data,
• Write a research report discussing their hypotheses, methods, and results,
• Present a research project using a PowerPoint.

Flow of Activities

Step 1: Form groups and develop a hypothesis, or multiple hypotheses

Using the comparative framework below, consider questions you might ask about how reproductive modes and reproductive biology of organisms may relate to their distributions, range sizes, ecological niches, other aspects of their biology, and many other traits. Discuss with your group members potential research questions and hypotheses. Develop one or two hypotheses or research questions that you want to explore during this project.

            See ‘Hypothesis and Sampling Design’ tutorial. And ‘annotated bibliography’ assignment.

Step 2: Generate Dataset

You will access images of specimens via The New York Botanical Garden virtual herbarium. Then, you will record character states in a google sheet with your group mates. The characters you choose to record and how you record them will depend on your hypotheses. Recording data will require careful organization.

See the ‘How to generate your dataset’ and ‘A guide to species and structures’ tutorials for further instructions.

Step 3: Mapping Distributions and Calculating Range Sizes in QGIS

Once you finish generating your trait dataset you will then map the occurrences, learn how to change the symbology in a map to visualize data, and calculate range sizes. This step will generate figures for your final presentation and paper, and will allow you to complete your dataset for statistical analysis.

            See the ‘Cartography and spatial analysis’ tutorial for further instructions.

Step 4: Statistical Analyses

At this point your dataset will be completely assembled. The next step will be to perform appropriate statistical tests. Depending on the hypotheses your group developed you may use t-tests, ANOVAs, spearman correlation, linear regression, or another statistical analysis.

            See ‘Statistical analyses in JASP’ tutorial for further instructions.

Step 5: Communicating Results

You will communicate your findings through writing a scientific paper and giving an oral presentation. Your written results will take the typical form of a scientific primary literature and included a title, authors, abstract, introduction, methods, results, discussion, and literature cited sections. Oral presentations will be similarly organized.

            See ‘Research report’ and ‘Oral presentation’ instructions for additional details.

Curriculum Materials Provided

The material for this CURE are organized into four folders: 1. Overview document and PowerPoints, 2. Tutorials, 3. Assignment instructions, and 4. Shapefile baselayers for the mapping portion of the CURE.

Contact Information

Corresponding author: Jessica Allen, jallen73@ewu.edu

Funding

Creation of this content was supported by NSF DEB #2115191 to JLA and NSF DEB #2115190 to JCL.

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