He arctic ice It covers seas where the temperature barely allows life, but this environment is essential for one of the most emblematic species on the planet: the polar bear. Its name reflects the frozen territory it requires to hunt, move and breed, a space that is now shrinking at an alarming rate. The ice floes are disappearing and with them the places from which these animals capture seals, their main prey. That the loss of frozen surface changes their habits displacement and reduces their chances of survival.
Each melt season comes earlier, ice-free periods lengthen, and bears have to retravel greater distances to find foodwith the resulting energy expenditure. The reduction in sea ice thus becomes a permanent environmental pressure which begins to leave a visible mark on its physiology and, according to scientists, also on its nature. DNA.
An academic team has detected hereditary alterations linked to thermal increase
The University of East Anglia detected Genetic changes in polar bears from southeast Greenland this could help them survive rising temperatures. The study, published in the journal Mobile DNAanalyzes how these animals are adapt their genetic material to a warmer environment.
According to its main author, Alicia Goddenresearcher at the School of Biological Sciences of this university, the DNA sequences of polar bears undergo accelerated changes due to environmental stress generated by global warming. The expert says these variations could offer a pathway to biological resistance to the extreme conditions of the Arctic, which are now changing rapidly.
Godden’s team compared the genomes of specimens from north and southeast Greenland. The analyzes revealed that in warmer southern regions, genes related to metabolism and heat response behave differently, suggesting a recent evolutionary adaptation. This difference coincides with a contrasting increase in temperatures in this region, where the ice melts earlier and the thermal variation is greater.
Researchers have identified a key element in this process: the let’s transposealso known as skipping genes. These mobile DNA fragments make up about 38% of the polar bear genome and can move to different positions within cells, causing mutations or genetic rearrangements. “Transposons are like puzzle pieces that can be rearranged, that sometimes helps animals adapt to new environmentss,” Godden explained in an article published in The conversation.
Demographic estimates have confirmed a very compromised future for the species
The general situation of the species remains worrying. With an estimated population of between 22,000 and 31,000 individuals, polar bears are classified by the World Wildlife Fund as vulnerable species. Various studies predict that by 2050, two thirds of them could disappear and that These species could disappear before the end of the century.
The researchers point out that the specimens from southeast Greenland, in addition to modifying their genome, are slowly change your diet. Retreating ice has reduced access to blubber-rich seals, and some bears now feed on harder and less caloric plants. This dietary adjustment reflects a forced adaptation to the new environment and offers clues about how they might survive in an increasingly warmer Arctic.
The University of East Anglia study shows that genetic transformations are more intense in southern populations than in those in the north, where temperatures are colder and more stable. This difference indicates that the evolution of polar bear DNA responds directly to climatic conditions. The authors warn, however, that these adaptations do not eliminate the risk of extinction, which is why they emphasize the need to we must stop the global rise in temperatures.
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