Polar Bears Show DNA Adaptations to Arctic Warming

Scientists at the University of East Anglia have discovered changes in polar bear DNA that may enable the animals to adapt to warmer Arctic conditions, marking the first statistically significant connection between rising temperatures and genetic shifts in a wild mammal species. The findings, based on blood samples from bears in northeastern and southeastern Greenland, reveal heightened activity in so-called jumping genes among those in the warmer southeast region, where sea ice is diminishing rapidly.

The study, published Friday in the journal Mobile DNA, examined RNA from 17 polar bears to assess gene expression and the behavior of jumping genes, which are mobile DNA segments that can influence other genes. Researchers compared samples from the colder, more stable northeast, where temperatures fluctuate less, to the southeast, which experiences steeper temperature swings and less ice cover. They linked these patterns to local climate data, finding that rising temperatures appear to drive a surge in jumping gene activity in southeastern bears. This activity concentrated in genes associated with heat stress, metabolism, ageing, and fat processing, potentially aiding survival...