With climate change steadily dismantling the icy habitat essential to their existence, new research suggests polar bears are rapidly rewiring their own genetics in a bid to survive.
The species is being forced to adapt to the harsher reality of a warming Arctic, in what scientists believe is the first documented case of rising temperatures driving genetic change in a mammal.
Researchers from the University of East Anglia in Britain say these findings, published Friday in the journal Mobile DNA, offer a rare glimmer of hope for the species.
"Polar bears are still sadly expected to go extinct this century, with two-thirds of the population gone by 2050," Alice Godden, who is the lead author of the study, told NBC News.
"I believe our work really does offer a glimmer of hope — a window of opportunity for us to reduce our carbon emissions to slow down the rate of climate change and to give these bears more time to adapt to these stark changes in their habitats."
Building on earlier University of Washington research, Godden’s team analyzed blood samples from polar bears in northeastern and southeastern Greenland. In the slightly warmer south, they found that genes linked to heat stress, aging and metabolism behaved differently from those in northern bears.
“Essentially this means that different groups of bears are having different sections of their DNA changed at different rates, and this activity seems linked to their specific environment and climate," Godden said in a university press release.
She said this shows, for the first time, that a unique group of one species has been forced to "rewrite their own DNA," adding that this process can be considered "a desperate survival mechanism against melting sea ice."
The Arctic Ocean has repeatedly experienced record-high temperatures in the past few years, National Oceanic and Atmospheric Administration (NOAA) monitoring data shows.
Researchers say warming ocean temperatures have reduced vital sea ice platforms that the bears use to hunt seals, leading to isolation and food scarcity.
This led to genetic changes as the animals’ digestive system adapts to a diet of plants and low fats in the absence of prey, Godden told NBC News.
"Food availability is a real problem for these bears — everywhere, but most prominently in the south," she said. "This may suggest their body shape and composition is also changing in response to their warmer environments."
The lead researcher said that her team decided to focus on the southern group of bears because the area's warmer climate serves as a glimpse of what is to come for other bear populations later this century if current trends in climate change continue.
The International Union for Conservation of Nature estimates there are currently about 26,000 polar bears worldwide. Scientifically known by its Latin name Ursus maritimus, meaning "sea bear," the animals are listed as vulnerable on the IUCN Red List of Threatened Species, meaning they are considered to be facing "a high risk of extinction in the wild."
The study "does not mean that polar bears are at any less risk of extinction,” Godden said, though the discovery may “provide a genetic blueprint for how polar bears might be able to adapt quickly to climate change.”
Godden added: "We all must do more to mitigate our carbon emissions to help provide and extend this window of opportunity to help save this wonderful vital species."
