A groundbreaking study, which explores how shifts in the environment in the last 20,000 years have impacted Arctic polar bear populations, not only offers insight into how these animals adapt to environmental changes but also serves as a warning about the potential harm climate change can wield on their future. 

Co-led by Dr. Paul Szpak, Tier 2 Canada Research Chair in Environmental Archaeology and director of the Trent Environmental Archaeology Lab and Water Quality Centre, the study is an international collaboration with researchers from 11 institutions and draws on a wealth of data, including genetic analysis, stable isotopes, climate modelling, mathematical modelling, and skull morphology, as well as a remarkable collection of polar bear skulls (some as old as 200 years) housed in Copenhagen. Their findings recently made the cover of Science Advances and painted a holistic picture of polar bear evolution and its correlation with climate dynamics. 

“We looked back at the genetic diversity of polar bears over thousands of years to measure how big the populations were at these different periods,” Professor Szpak explains. “We observed changes in population structure and genetic diversity during warmer periods with less sea ice. Based on this, we anticipate negative implications for polar bear populations as conditions continue to warm, especially as optimal sea ice habitat decreases.” 

A dynamic training ground for graduate students

Prof. Szpak acknowledged the vital role played by graduate students in his research.  

Julia McCuaig, an M.Sc. Anthropology student, worked alongside Prof. Szpak to prepare bone samples from the polar bear skull collection for stable isotope analysis in Trent’s world-renowned Water Quality Centre. She was delighted to be involved in such a comprehensive study and to further build on her stable isotope analysis skills, which she also utilizes in her research. 

“My current research utilizes stable isotope analysis to examine past agricultural practices during Moche rule in Peru,” Julia explains. “This project allowed me to continue utilizing stable isotope analysis on faunal remains and developed my confidence in preparing bone collagen for stable isotope research.”  

Finding answers at the intersection of disciplines 

As the scientific community grapples with the challenges posed by climate change, studies like these underscore the importance of collaborative efforts and multidisciplinary approaches to unravel the complexities of our planet's ecosystems. 

According to Prof. Szpak, the study brought together a remarkable group of people with diverse yet complementary skill sets.  

“When trying to address these big, unifying questions, it's really useful to work with a group of people who have these complementary skill sets which multiply together into something much greater than then than the sum of the parts,” he adds. “Together, we are generating really unique insights that we wouldn't have gotten from one line of evidence in isolation – it really has to be about bringing multiple viewpoints together.” 

The group continues to work together to answer more questions relating to polar bears as well as other species across the globe. 

Also read this CP24 interview with Prof. Szpak about the study.