Thesis Defenses
Fall 2026
Josh Mata
Wednesday, September 2, 2026 - 1:00pm
Firmly Grasp It: Ecomorphology of the Hands and Feet of Anoles
Thesis Advisor: Dr. Thomas Sanger
Committee Members: Dr. Megan Whitney, Dr. Yoel Stuart, and Dr. Greg Mayer
Location: Quinlan Life Science Building (LSB) 312, Lakeshore Campus
Abstract:
Arboreality has evolved multiple times throughout tetrapod evolution, producing convergent morphological adaptations that assist in climbing and minimize falling. One such adaptation is grasping, the ability to manipulate objects or hold onto a substrate by moving and applying force with the hands and/or feet. In primates, differences in the wrist and ankle bones have been found between species that are arboreal and grasp versus terrestrial species that don’t. However, outside of mammals, the skeletal morphology enabling grasping has remained largely understudied in other tetrapod, arboreal species such as in lizards. Therefore, I investigated the morphology of the carpal and tarsal bones in anoles and their more terrestrial iguanian relatives using three-dimensional geometric morphometrics, testing for shape differences both among anole ecomorphs and between the arboreal anoles and their terrestrial relatives. I found no significant morphological differences in carpal and tarsal bone shape among ecomorphs, but significant divergence between anoles and their more terrestrial relatives. Compared to their relatives, anoles had narrower and longer carpal and tarsal bones, suggesting this represents an adaptation for grasping. These results suggest that this skeletal adaptation is tied to the broad transition from a terrestrial to an arboreal lifestyle, rather than the specialization to a particular microhabitat within anoles.
In the second chapter I address an observed carpal bone configuration where some Anolis species were missing distal carpal 1 (DC1). I hypothesized that this might similarly be explained by microhabitat use or by body size, another factor commonly linked to skeletal loss in tetrapods. However, I found no credible statistical support for either ecomorph or body size as predictors of DC1 loss. Embryonic staging revealed that DC1 is the last carpal element to form during development, suggesting its loss may reflect a developmental constraint. These hypotheses are not mutually exclusive, and the developmental constraints could play a role alongside body size and ecological adaptation to determine morphology.
Summer 2026
Olivia Schaul
Friday, August 21, 2026 - 1:30pm
Transport, Retention, and Industrial Sources of Plastic Pollution in an Urban River
Thesis Advisor: Dr. Timothy Hoellein
Committee Members: Dr. Martin Berg and Dr. Joseph Milanovich
Location: Cuneo Hall Room 103 Lakeshore Campus
Abstract:
Plastic pollution is a widespread contaminant in freshwater ecosystems. Rivers receive plastics from numerous point and non-point sources and transport plastic pollution from terrestrial environments to downstream lakes and oceans while also retaining plastics within stream channels and riparian habitats. Despite increasing recognition of freshwater plastic pollution as a key part of the global plastic cycle, relatively few studies have examined the processes controlling plastic transport through river networks or the influence of localized industrial point sources. In the first study, I examined how stormflow influenced the transport of macroplastics and microplastics at four sites within the North Branch of the Chicago River. Macroplastic transport increased during periods of elevated discharge, whereas microplastic concentrations showed relatively weak and inconsistent responses to stormflow, suggesting that particle size influences plastic transport dynamics. For both particle types, storm flows represented the major component of plastic export from the watershed. In the second study, I investigated the distribution, transport, and retention of pre-production plastic pellets (i.e.,“nurdles”) originating from a suspected industrial point source within the Middle Fork of the North Branch of the Chicago River. Nurdles were consistently absent from upstream reference sites but present at all sampling locations downstream of the suspected point source, providing strong evidence of its role in introducing nurdles to the stream. Nurdle abundance was variable throughout the 4.3-km study reach downstream of the point source, accumulating in high-density patches within floating vegetation, rather than declining evenly with distance from the source. These results will improve our understanding of the hydrologic and habitat-specific processes driving plastic transport and retention in freshwater ecosystems and support future monitoring, source identification, and management of plastic pollution in urban rivers.
Valerie Trinidad
Monday, August 17, 2026 - 9:00am
Paleoecology and Geology of Upper Cretaceous Lance Creek Vertebrate Microsites
Thesis Advisor: Dr. Megan Whitney
Committee Members: Dr. Megan Whitney, Dr. Martin Berg, and Dr. Yoel Stuart
Location: Quinlan Life Science Building (LSB 316), Lakeshore Campus
Summer 2025
Ryan Krantz
Friday, July 25, 2025 - 1pm
Interactions Between Microplastics, Biofilms, and Antimicrobials in Freshwater Streams
Ryan Krantz Thesis Defense Abstract
Thesis Advisor: Dr. John Kelly
Committee Members: Dr. Michael Burns and Dr. Tim Hoellein
Location:
Quinlan Life Science Building (LSB) 312 on Lakeshore Campus
Join Zoom Meeting - https://luc.zoom.us/j/86180736072
Alex Acker
Wednesday, July 9, 2025 - 12pm
New Insights on the Cranial Anatomy and Osteohistology of Cyonosaurus
Alex Acker Thesis Defense Abstract
Thesis Advisor: Dr. Megan Whitney
Committee Members: Dr. Yoel Stuart and Dr. Thomas Sanger
Location:
Mundelein 403 on the Lakeshore Campus
Join Zoom Meeting - https://us05web.zoom.us/j/88558738756?pwd=U1sHCR7YynYQ8DbjrTiuVhUls0o5i7.1
Ryan Johnson
Wednesday, June 18, 2025 - 12pm
Response of Benthic Macroinvertebrate Community Structure and Aquatic Insect Secondary Production to Coarse Woody Debris Addition in Peri-Urban to Urban Golf Course Ponds
Abstract - Ryan Johnson Thesis Defense
Thesis Advisor: Dr. Martin Berg
Committee Members: Dr. Timothy Hoellein and Dr. Joseph Milanovich
Location:
Quinlan Life Science Building (LSB) 312 on Lakeshore Campus
Join Zoom Meeting - https://luc.zoom.us/j/86314835048
Spring 2025
Katelyn Wendt
Friday, Mar. 14, 2025 - 1pm
Loss of Neuropeptide F (NPF) Signaling Reduces the Strength of Circadian Rest: Activity Rhythms but not Feeding: Fasting Rhythms
Location:
Mundelein 1410 on the Lakeshore Campus
Join Zoom Meeting - https://luc.zoom.us/j/84342411704
Meeting ID: 843 4241 1704
Emma O'Flaherty
Thursday, Mar. 13, 2025 - 10am
Regulation of Spermatogenesis by the Notch Signaling Pathway
Thesis Advisor: Dr. Jennifer Mierisch
Committee Members: Dr. Rodney Dale, Dr. Terry Grande, Dr. Thomas Sanger
Location:
Cuneo Hall (CH) 410 on the Lakeshore Campus
Join Zoom Meeting - https://luc.zoom.us/j/82213373255
Meeting ID: 822 1337 3255
Fall 2024
Emily Johnson
Friday, Dec. 13, 2024 - 1pm
Anthropogenic Litter in Freshwater Ecosystems: Effect on Ecosystem Processes and Spatial Distribution
Abstract: Emily Johnson Thesis Defense
Thesis Advisor: Dr. Tim Hoellien
Committee Members: Dr. Martin Berg, Dr. Joseph Milanovich
Cuneo Hall (CH) 107 on the Lakeshore Campus