As a rising senior at Yorktown High School, Sonia Eddolls is already contributing to ground-breaking research at the University of Michigan Museum of Paleontology. Eddolls participates in the Yorktown High School Science Research program, an immersive college-level curriculum that gives students real-world experience in science research. Inspired by a study conducted at UMMP by Michael Cherney, Daniel Fisher, and collaborators that was published in the spring of 2023, Eddolls wanted to study hormones preserved in mammoth and mastodon tusks as her research project. After several months of planning and preparation, Eddolls volunteered for 5 weeks in June and July 2024, sampling tusks and analyzing data from two mastodons (an adult male and an adult female) and one adult female elephant. These data will advance recent efforts to study endocrinology (and paleoendocrinology) of elephants and their extinct relatives using traces of steroid hormones preserved in their tusks.
Building on the results of the Cherney, Fisher, et al. study showing testosterone surges that revealed individual episodes of musth (an annual period of heightened aggression and mating effort in bull elephants) in the growth record of a permafrost-preserved 30,000-year-old woolly mammoth from Siberia, Eddolls was interested to see if she could get similar records for male mastodons. She also wanted to explore the possibility of detecting pregnancies in steroid hormone records from tusks of female elephants and mastodons. Eddolls’ project is an extension of a collaboration between UMMP researchers and Dr. Richard Auchus in the division of Metabolism, Endocrinology, and Diabetes in the UM Medical School.
During her brief stay in Ann Arbor, Eddolls quickly learned the ropes for sampling tusk growth records, picked up experience processing microCT data, mastered use of the micromill in the stable isotope lab of Kacey Lohmann (using a machine still running Windows NT 4.0—software from nearly 10 years before she was born!), and learned procedures pioneered at the University of Michigan for extracting and analyzing steroid hormones in the tusk dentin. Over the course of five weeks, she produced over 200 tusk samples representing a total of 15 years of growth split between the three animals. The data she produced will help identify evidence of pregnancies in tusk hormone records and might provide the first meaningful hormone data from non-permafrost remains of mastodons.
After completion of her senior year at Yorktown High School, Eddolls hopes to return to Ann Arbor to attend the University of Michigan as an undergraduate student in Biology.
