Scientists have detected modifications in polar bear DNA that could enable the creatures acclimatize to hotter climates. This study is considered to be the first instance where a notable association has been found between escalating heat and evolving DNA in a free-ranging mammal species.
Global Warming Puts at Risk Polar Bear Existence
Climate breakdown is imperiling the survival of polar bears. Forecasts indicate that a significant majority of them might disappear by 2050 as their snowy environment melts and the weather becomes more extreme.
“DNA is the blueprint inside every biological unit, instructing how an life form evolves and develops,” said the principal investigator, Dr. Alice Godden. “By comparing these bears’ active genes to regional climate data, we found that rising temperatures seem to be fueling a substantial surge in the activity of transposable elements within the warmer Greenland region bears’ DNA.”
Genetic Analysis Reveals Key Adaptations
Scientists examined biological samples taken from polar bears in two regions of Greenland and contrasted “transposable elements”: tiny, mobile pieces of the genetic code that can alter how various genes work. The research focused on these genetic markers in correlation to temperatures and the corresponding variations in DNA function.
As regional weather and food sources evolve due to changes in habitat and prey driven by climate change, the DNA of the animals appear to be adjusting. The community of polar bears in the hottest part of the region showed greater genetic shifts than the populations to the north.
Likely Adaptive Strategy
“This result is important because it demonstrates, for the first time, that a unique group of polar bears in the warmest part of Greenland are employing ‘mobile genetic elements’ to quickly rewrite their own DNA, which might be a essential adaptive strategy against melting sea ice,” added Godden.
The climate in the northern area are less variable and more stable, while in the southern zone there is a more temperate and more open water area, with steep temperature fluctuations.
Genetic code in organisms mutate over time, but this evolution can be accelerated by environmental stress such as a changing planet.
Nutritional Changes and Key Genomic Regions
There were some interesting DNA alterations, such as in sections connected to energy storage, that may aid polar bears survive when resources are limited. Animals in temperate zones had more terrestrial food intake compared with the fatty, seal-based nutrition of Arctic bears, and the DNA of south-eastern bears seemed to be adapting to this new reality.
Godden elaborated: “We identified several key genomic regions where these mobile elements were particularly busy, with some found in the functional gene sections of the DNA, implying that the animals are undergoing rapid, fundamental DNA modifications as they adjust to their disappearing sea ice habitat.”
Next Steps and Broader Impact
The following stage will be to study additional subspecies, of which there are 20 globally, to observe if analogous genetic shifts are taking place to their DNA.
This investigation might assist safeguard the bears from dying out. However, the experts stressed that it was crucial to slow temperature rises from increasing by reducing the consumption of carbon-based fuels.
“We must not relax, this provides some hope but is not a sign that polar bears are at any diminished risk of disappearance. It remains crucial to be pursuing every action we can to lower greenhouse gas output and mitigate climate change,” concluded Godden.
