Climate change linked to DNA changes in polar bears, study finds

A new study suggests that warming temperatures are linked to changes in polar bear DNA, offering a potential glimpse into how the species might adapt as Arctic ice melts. Researchers found a statistically significant association between rising local temperatures and the activity of so-called jumping genes—mobile DNA elements that can influence how other genes work—in polar bears in Greenland. The work, published in Mobile DNA, is described by the authors as the first widely supported link between climate change and rapid genetic changes in a wild mammal.

Scientists at the University of East Anglia analyzed blood samples from polar bears in two regions of Greenland and compared the activity of jumping genes with local temperature data and observed dietary shifts. The southeast Greenland population, which lives in a warmer and more variable climate with less sea ice, showed more pronounced changes than bears farther north, where conditions are colder and more stable. The researchers also note that climate breakdown is threatening polar bears’ survival: two-thirds of the species are expected to disappear by 2050 as habitat melts and weather grows hotter. The study highlights how environmental stress can accelerate genetic changes, potentially aiding bears in coping with a changing environment.

Lead researcher Alice Godden described the significance of the findings, saying, “DNA is the instruction book inside every cell, guiding how an organism grows and develops. By comparing these bears’ active genes to local climate data, we found that rising temperatures appear to be driving a dramatic increase in the activity of jumping genes within the southeast Greenland bears’ DNA.” The study notes that these genetic changes—some in regions that code for proteins involved in fat processing and metabolism—could reflect rapid adaptation to food scarcity and shifting prey, including changes in diet from fatty seal-based fare to more plant-based resources in warmer regions.

The team emphasizes that while the changes offer some cause for cautious optimism, they do not imply that polar bears are safe from extinction. “We cannot be complacent; this offers some hope but does not mean that polar bears are at any less risk of extinction,” Godden said. The authors stress that ongoing warming and continued loss of sea ice remain existential threats, underscoring the need to curb fossil fuel use and slow temperature increases. The researchers plan to study additional polar bear populations—roughly 20 groups worldwide—to determine whether similar genetic patterns are emerging elsewhere and to refine conservation strategies.

In addition to documenting regional differences, the study highlights how environmental stress can accelerate genetic change. The southeast Greenland bears—facing a warmer, more variable climate with projected greater ice loss—also showed dietary shifts toward less fatty, plant-based foods compared with northern bears. Such ecological changes may interact with genetic dynamics, helping explain why jumping gene activity appears elevated in bears in the warmest part of their range. The authors say identifying these genetic hotspots could improve understanding of how different polar bear populations are evolving and help prioritize conservation efforts as the Arctic continues to transform. While these discoveries deepen scientific insight, they also reinforce the imperative for reducing global carbon emissions to slow temperature rise and protect polar bears from further decline.