Todd Widhelm
Collections Management & Phylogenetic Research
Bio
I grew up in North Bend, Nebraska, and I’ve had a passion for science and nature that started when I used to go on hikes in the flood plain forests along the Platte River.
During my undergraduate degree I worked as a biological technician in the Nebraska Sand Hills and the Iowa Loess Hills. But near the end of my program, I became especially interested in lichens.
After intensive studying and hard work at the University of Nebraska at Omaha (M.S.) and the University of Illinois at Chicago (Ph.D.), I graduated and then became a Collection Manager at the Field Museum.
In this position, I enjoy delving into different projects everyday. Most important is the management of the Fungal Herbarium where I manage a team that helps with digitization of specimens. I also conduct field work that brings in new specimens from all over the world and conduct phylogenomic and population genomic research on lichens.
Projects
Collections Management, Field Work, & Phylogenetics of Lichenized Fungi
Management of the Fungal Herbarium
The total fungal collection at the Field Museum currently contains 293,000 specimens
Lichens: 108,000
Basidiomycetes: 117,000
Nonlichenized ascomycetes: 68,000
Objectives:
Re-packet the portions of the collection that are inappropriately housed in old packets or in field collection bags. 
Digitally photograph labels and barcodes and enter the data into our online database.
Enter core fields of taxon, country, collector, collection number, and date into the database.
Link genetic (DNA isolation and GenBank accession numbers) and chemical data to each specimen’s record in the database.
Share specimen data and loan specimens to other herbaria, as well as distribute duplicate sets of identified material to other herbaria.
Provide a preliminary identification to genus or family for material that has not yet been determined. Upon determination these will be re-packeted, labelled with updated information and deposited in the herbarium.
Fieldwork and Workshops
I recently was invited to conduct a lichen collection and identification course as part of a larger workshop organized by Steve Goodman at the Field Museum. Professionals and students learned about lichen biology, how to collect specimens, and how to identify lichens. Nearly 600 specimens were collected, mostly by the people attending the workshop. These specimens were duplicated and a reference collection is at the Field Museum and the University of Antananarivo.
Research
Next Generation Systematics of Peltigeralean Lichens
In the age of next-generation sequencing, the number of loci available for phylogenetic analyses has increased by orders of magnitude. I use a next-generation approach called target enrichment to sample hundreds of single-copy nuclear genes and estimate the phylogenetic relationships of lichen-forming order Peltigerales. Currently, this order of lichens is understudied and the phylogenetic relationships of families and genera is still unclear. Using this approach, I will be able to gain a clearer understanding of relationships among families in Peltigerales and be able to stabilize the taxonomic classification in this group. Furthermore, I will examine datasets for evidence of historical processes, such as rapid diversification and ancient hybridization and estimate divergence times in Peltigerales.
Population Genomics of Widespread Lichen Species
Lichenized fungi can have widespread, disjunct distributions that are separated by large barriers such as mountain ranges and oceans. Finding species with such distributions and collecting samples from the entire disjunct range allows for testing whether major physical barriers result in genetic differentiation among populations and if speciation is or has occured. Hypotheses can be tested such as, (1) if large barriers isolate populations of a particular lichen species, then these populations will be genetically distinct, and (2) given the wind patterns, ocean currents, or migratory birds, lichen populations will either be connected by frequent and ongoing long-distance dispersal (i.e. gene-flow) or isolated and perhaps undergoing speciation. Large distances between populations should generate genetically distinct clusters and possibly new species, but if connected by wind, currents or birds, migration may be frequent enough to prevent speciation.
Lichens
Lichens are a symbiosis of fungi (mycobionts), and a photosynthetic partner (photobionts), either algae or cyanobacteria. Some mycobionts associate with both types of photobionts. Ecologically, lichens act like plants.
Contact Me
Field Museum
Gantz Family Collection Center
1400 South Lake Shore Drive, Chicago, IL, 60605
Office: 312-665-7057