Polar Bears Adapt to Warmer Climates
A new study shows that there is a link between rising temperatures and changes in polar bears’ DNA. This may help the bears adapt to increasingly challenging environments.
The study shows that certain genes linked to heat stress, ageing and metabolism differ in polar bears in south-eastern Greenland – suggesting that they are adapting to warmer conditions.
The researchers analysed blood samples taken from polar bears in north-eastern and south-eastern Greenland to compare the activity of so-called ‘jumping genes’, small, mobile parts of the genome that can affect how other genes function, in relation to the temperature in the two regions.
Genetic blueprint
Northeastern Greenland proved to be colder and had less temperature variation, while the differences in the southeast were greater and the environment milder and less icy – something that resembles the future conditions polar bears are expected to face.
‘Since the rest of the species is threatened with extinction, these specific bears represent a genetic blueprint for how polar bears can adapt quickly to climate change,’ said Alice Godden, from the Department of Biology at the University of East Anglia, who led the study, in a comment.
Not enough
She explains that the polar bears’ unique genetic code is important for conservation efforts, but that it is not enough to save the species.
‘This certainly gives us hope – but it does not mean that polar bears are less at risk of extinction. We must still do everything we can to reduce global carbon dioxide emissions and slow down global warming.’
The polar bear is listed as vulnerable by the International Union for Conservation of Nature (IUCN), and a large proportion of the world’s polar bears are expected to be extinct by 2050. As the Arctic Ocean gets warmer, the sea ice is forming later and later, meaning that polar bears are unable to go out and hunt seals to replenish their fat reserves.
The study is published in the journal Mobile DNA.
Cover image: Melting sea ice makes it harder for polar bears to go out and hunt seals to replenish their fat reserves. Archive image. Photo: David Goldman/AP/TT
Polar bears are found in many places in and around the Arctic, including Greenland, northern Canada, Alaska and northern Russia.
There are between 22,000 and 31,000 wild polar bears.
The species is classified as vulnerable, which means that it is considered to be at high risk of extinction in the wild.
For a long time, hunting was the greatest threat to polar bears. But today, with hunting regulated, it is global warming that threatens their natural environment.
Source: WWF, NE.se
