Polar bears are evolving right before our eyes as their world gets hotter. A unique group of these bears has been spotted in southeastern Greenland, thriving in a climate much warmer than their typical habitat. Researchers believe these animals are showing crucial genetic changes that could help them survive in changing conditions.
According to a study in Mobile DNA, this isolated group of polar bears might have had a 200-year head start on adapting to their warmer environment. Co-author Alice Godden noted that these bears display distinct genetic traits compared to their colder-weather relatives.
The team examined blood samples from both northern and southern bears. They discovered that some genes linked to heat stress and metabolism were reacting differently in the bears from the south. Godden pointed out that this suggests rising temperatures are triggering these genetic changes.
Central to this adaptation are “jumping genes,” or transposons, which are bits of DNA that can move around within the genome. These genes may help the southern polar bears adapt to their new diets, which increasingly rely on plant-based foods due to food scarcity. In contrast, their northern cousins mainly feast on fatty seals. Interestingly, about 38.1% of the polar bear genome consists of these jumping genes; humans have 45%.
The dramatic shift in conditions is alarming. Reports predict that by 2050, over two-thirds of polar bears may face extinction, with total extinction likely by 2100. The Arctic Ocean is heating up, reducing the sea ice these bears need to hunt and leading to food shortages. This genetic adaptation is believed to be the first documented case of rising temperatures influencing genetic change in a mammal.
While these changes might offer some hope, Godden warns that they don’t lessen the risk of extinction. Immediate action is crucial to combat climate change. Without controlling carbon emissions, we jeopardize not only polar bears but also the ecosystems they inhabit.
It’s fascinating to consider that, much like polar bears, human DNA could also adapt under environmental stress. As climates change, our genetic makeup might also shift, demonstrating how interconnected life on Earth truly is.
For deeper insights on climate change and its impact on species, you might check out this report from NBC News. Understanding these dynamics can help us take meaningful steps to protect our planet.
