Polar bears face one of the toughest survival challenges in their history as the Arctic warms far faster than the rest of the world, shrinking the sea ice they rely on to hunt, rest, and travel. As ice melts earlier and returns later each year, many bears struggle to find enough seals, leading to weight loss, fewer cubs, and higher death rates. Scientists warn this loss of ice could drive polar bears toward extinction within decades, but new research suggests some populations may be responding through changes in their DNA that help them cope with warmer conditions and limited food, revealing a critical biological response even as serious risks remain.
Climate change is reshaping the polar bear’s world
The Arctic is warming two to four times faster than the global average. This extreme warming has dramatic effects on sea ice, which is the foundation of the polar bear’s life. Polar bears hunt seals by waiting near holes in the ice or by stalking them across frozen platforms. When ice disappears, these hunting methods become far less effective.
With less ice available, polar bears must travel longer distances to find food. Many bears are forced onto land, where food options are limited and often less nutritious. This leads to longer periods without eating, which weakens their bodies and reduces their ability to reproduce.
Scientists predict that more than two-thirds of the world’s polar bears could disappear by 2050 if warming continues at current rates. Some projections even warn of total extinction by the end of this century. These alarming predictions are based on shrinking ice, declining food sources, and the isolation of bear populations from one another.
Yet, despite these harsh conditions, polar bears are not standing still. Their bodies may be trying to adjust in ways that were not fully understood before. New genetic research suggests that some bears are undergoing fundamental changes that could help them survive, at least in the short term, in a warmer Arctic.
Jumping genes and how DNA is responding to heat
Every polar bear carries a complex set of genetic instructions. Among them, tiny pieces of DNA called “jumping genes” move within the genome and influence how other genes behave. They do not change the DNA sequence itself, but they control how strongly certain genes switch on or off.
Scientists examined blood samples from polar bears living in different parts of Greenland. These regions experience very different temperatures. Bears in the south live in much warmer conditions than those in the north, where ice lasts longer each year.
The study found a dramatic increase in the activity of jumping genes in bears living in the warmer southeastern region. This increase was closely linked to higher temperatures. In colder northern areas, jumping gene activity remained much lower.
These active jumping genes appear to affect how polar bears manage heat stress and energy use. Some of the changes affect metabolism, which controls how the body uses food and stores fat. This is especially important for polar bears, which often go long periods without eating.
The DNA changes may help bears survive with less food and cope better with warmer temperatures. Scientists describe this process as a kind of emergency response. It may allow polar bears to adjust more quickly than traditional evolution, which usually takes many generations.
This genetic flexibility could explain how some bears continue to survive in areas where sea ice has become unreliable. It shows that polar bears are not only victims of climate change but are also biologically responding to it in real time.
Diet shifts and ongoing extinction risk of Polar Bears
Another important discovery from the research involves changes in gene expression linked to fat processing. Polar bears traditionally rely on a diet rich in seal fat, which provides the high energy they need to survive cold conditions. However, as seals become harder to catch, some bears are forced to eat alternative foods.
In warmer regions, polar bears may consume more plant material, bird eggs, or other land-based foods. These foods are lower in fat and energy compared to seals. The study suggests that changes in DNA activity may help some bears process these rougher diets more efficiently.
This does not mean plant-based food can fully replace seals. Polar bears are still specialized hunters designed for a high-fat diet. However, the genetic changes may help them survive during longer periods of food shortage. Despite these adaptations, polar bears remain at serious risk. Genetic changes alone cannot replace the loss of sea ice. The study makes it clear that these DNA shifts offer only limited support. They do not remove the threat of extinction or guarantee long-term survival.
Researchers stress that polar bears are still highly vulnerable to rising temperatures. Their survival depends heavily on the presence of sea ice. Without it, even the most flexible genetic responses may not be enough. The findings highlight the urgency of understanding polar bear genetics before populations decline further. Scientists plan to study other polar bear groups to see whether similar genetic patterns appear elsewhere. This information could help guide conservation strategies focused on protecting the species while there is still time.
Polar bears may be adapting at the genetic level, but the pressure from climate change continues to grow. Their future remains closely tied to the fate of the Arctic ice they depend on every day.
