Researchers have observed modifications in polar bear DNA that might assist the mammals acclimatize to increasingly warm climates. This study is believed to be the first instance where a statistically significant link has been found between escalating temperatures and evolving DNA in a free-ranging mammal species.
Climate Breakdown Endangers Polar Bear Survival
Environmental degradation is threatening the existence of Arctic bears. Forecasts show that two-thirds of them could vanish by 2050 as their snowy home retreats and the climate becomes hotter.
“DNA is the instruction book inside every cell, guiding how an creature develops and matures,” explained the principal investigator, Dr. Alice Godden. “Through analyzing these bears’ functioning genes to local climate data, we found that increasing temperatures appear to be driving a significant increase in the function of transposable elements within the specific area polar bears’ DNA.”
Genome Research Shows Important Adaptations
Scientists analyzed tissue samples taken from polar bears in different areas of Greenland and compared “mobile genetic elements”: compact, mobile pieces of the genetic code that can alter how various genes work. The research looked at these genes in relation to temperatures and the associated variations in genetic activity.
As local climates and diets change due to changes in habitat and food supply forced by warming, the genetics of the bears seem to be evolving. The group of polar bears in the warmest part of the country displayed greater genetic shifts than the groups in colder regions.
Possible Survival Mechanism
“This result is significant because it shows, for the first instance, that a unique group of Arctic bears in the warmest part of Greenland are employing ‘jumping genes’ to quickly modify their own DNA, which might be a critical survival mechanism against disappearing Arctic ice,” commented Godden.
Temperatures in north-east Greenland are more frigid and less variable, while in the south-east there is a more temperate and less icy environment, with steep weather swings.
Genetic code in animals change over time, but this evolution can be sped up by climate pressure such as a quickly warming planet.
Nutritional Changes and Key Genomic Regions
Scientists observed some notable DNA changes, such as in regions associated to energy storage, that might assist polar bears persist when prey is unavailable. Bears in temperate zones had increased fibrous, vegetarian diets versus the lipid-rich, marine nutrition of northern bears, and the DNA of these specific animals seemed to be evolving to this shift.
Godden explained further: “We identified several key genomic regions where these mobile elements were particularly busy, with some situated in the functional gene sections of the DNA, indicating that the bears are undergoing swift, fundamental genetic changes as they respond to their vanishing Arctic home.”
Next Steps and Broader Impact
The subsequent phase will be to examine other Arctic bear groups, of which there are numerous around the world, to observe if comparable changes are taking place to their DNA.
This research might assist protect the bears from dying out. However, the scientists stressed that it was crucial to slow temperature rises from increasing by lowering the use of coal, oil, and gas.
“Caution is still required, this provides some optimism but does not mean that Arctic bears are at any reduced danger of disappearance. We still need to be pursuing all measures we can to reduce pollution and decelerate temperature increases,” summarized Godden.
