Scientists report early genomic shifts in a southeastern Greenland polar bear population that diverged about 200 years ago. The changes — linked in part to active transposons or "jumping genes" — affect genes tied to heat stress, metabolism and ageing. These shifts may help the bears cope with warmer, less icy habitats, but researchers warn this is not a guarantee of long-term survival and emphasize the need to cut emissions.
Polar Bears Evolving in Real Time: Genetic Shifts in Southeastern Greenland Offer Conservation Clues
The Polar Bears of the Arctic are EvolvingBelfalah Soufian / 500px - Getty Images
Polar bears are among the species most exposed to climate change because they depend on sea ice to hunt seals. A new genetic study of a small polar bear population in southeastern Greenland finds early genomic changes that may help those bears cope with warmer, less-icy conditions — offering a potential biological blueprint for conservation, while underscoring that climate action remains essential.
Study Overview and Methods
Researchers from the University of East Anglia expanded on a 2022 University of Washington study to compare blood-derived genetic data from polar bears in southeast and northeast Greenland. The population in the southeast diverged from northern populations about 200 years ago. By combining genetic analyses with regional climate records, the team identified consistent differences in genes tied to heat stress, metabolism and ageing between the two groups.
Jumping Genes, Gene Expression, and Possible Adaptation
The study links many of the observed genetic shifts to transposons (TEs), often called "jumping genes" — mobile DNA elements that can move within the genome and alter how other genes are expressed. According to co-author Alice Godden of the University of East Anglia, roughly 38.1% of the polar bear genome is composed of TEs (compared with about 45% in humans). Normally, piwi-interacting RNAs (piRNAs) help suppress TE activity; however, the researchers suggest that under strong environmental stress (for example, rapid warming and habitat change) these protective systems can be overwhelmed, allowing TEs to become more active and potentially drive rapid genomic change.
“We found active jumping genes in parts of the genome involved in fat processing — important when food is scarce,” Alice Godden wrote for The Conversation. “This could mean that polar bears in the southeast are slowly adapting to diets that include rougher, more plant-based foods available in warmer regions.”
Different Ecosystems, Different Pressures
Although both populations inhabit the same island, the northeast and southeast of Greenland represent distinct ecosystems. Northeast Greenland is dominated by flat Arctic tundra where polar bears rely heavily on high-fat seal blubber. By contrast, southeast Greenland includes forest-tundra transition zones — a mosaic of coniferous patches and open tundra — where food availability and types differ and may favor metabolic flexibility.
Implications and Caution for Conservation
Because the southeastern group separated roughly two centuries ago — decades before large-scale industrial drilling — researchers argue these bears may serve as an early indicator, or genetic blueprint, for how other polar bear populations could respond to warming. The Arctic is warming at roughly four times the global average in part because of changes in surface reflectivity known as the albedo effect.
However, the authors are clear that these genomic signals are not a silver bullet. While they offer cautious hope, they do not remove the species' extinction risk. Conservationists stress that reducing global greenhouse gas emissions and protecting critical habitat remain essential to polar bear survival.
Where to Read the Study
The findings were published in the journal Mobile DNA and build on prior genetic work led by researchers at the University of Washington in 2022.
