The University of East Anglia study reports rapid genetic changes in some polar bears that appear linked to warming Arctic conditions. Researchers — led by Alice Godden — reanalyzed earlier samples and climate data and found the strongest genomic shifts in southeastern Greenland bears, including changes in "jumping genes" associated with increased plant consumption. The work is notable but limited by small sample size; experts stress adaptation has limits and call for emissions reductions to protect the species.
Polar Bears 'Rewriting' Their DNA: Study Finds Rapid Genetic Shifts in a Warming Arctic
Polar bears are 'rewriting their DNA' to survive warming Arctic, study suggests
A new study from the University of East Anglia finds evidence that some polar bears are undergoing rapid genetic changes that appear linked to warming Arctic conditions. Researchers say these shifts may represent a short-term biological response to environmental stress — but stress that the changes are limited and cannot replace large-scale climate action.
"This is one of the first mammal systems where temperature appears to be the primary driver, with increased thermal stress affecting the genome in near real time," Alice Godden, the study's lead author, told ABC News.
What Researchers Found
Scientists reanalyzed blood-sample data originally collected by a University of Washington study and then applied climate and temperature data to genomic analyses. They focused on polar bears from southeastern Greenland — the warmest part of the species' range — and compared them with bears from the colder northeastern region.
The earlier work showed that southeastern and northeastern Greenland populations diverged roughly 200 years ago. Godden's team then examined genomic changes in 17 individual bears to test whether warming and environmental shifts could be associated with recent genetic differences.
Rixipix/Getty Images - PHOTO: A polar bear in Viking Bay, Greenland.
Role of 'Jumping Genes' and Diet
Researchers paid special attention to transposable elements (commonly called "jumping genes"), DNA sequences that can move within the genome and sometimes change how genes work. Their analysis suggests southeastern Greenland bears show genomic signatures consistent with shifts in diet — notably an increased incorporation of plant material alongside the traditional high-fat, seal-based diet.
"Normally, a polar bear would hunt seals and have a very high-fat diet, but we're seeing evidence that some bears are eating more plant-based foods," Godden said. The genomic signals linked to these dietary shifts may reflect adaptive responses to reduced sea ice and altered prey availability.
Context and Caveats
Key caveats are important: the sample size analyzed by Godden's team was small (17 bears), and genomic correlations with temperature do not prove causation. The study identifies a plausible and notable pattern of rapid genetic change, but further research with larger sample sizes and long-term monitoring is needed to confirm mechanisms and population-level outcomes.
Kristian Septimius Krogh/Getty Images - PHOTO: A polar bear in Greenland.
Conservation context: polar bears are listed as "threatened" under the U.S. Endangered Species Act (listed in 2008), and global population estimates are roughly 26,000 individuals. Projections cited by researchers warn that, if current trends continue, as many as two-thirds of polar bears worldwide could be lost by 2050.
Implications
Scientists describe the findings as a cautious note of hope: some bears may be showing rapid genomic responses to a changing environment, but such biological flexibility has limits. The study reinforces that reducing greenhouse gas emissions and protecting sea-ice habitat remain essential to the species' long-term survival.
Bottom line: The research highlights a striking biological response in a threatened species, underscores the urgency of climate action, and points to the need for broader, longer-term genomic and ecological studies.
