Because of the melting ice, polar bear genes are dissolving into the grizzly brown bear population
In 2006, hunters killed an extraordinary Arctic bear - a white with brown spots. Geneticists analyzed the animal's DNA and came to the conclusion that the bear did not get dirty, but was born from two different species - a polar bear and a grizzly bear. Scientists called the polar grizzly "pizzly" (pizzly). In 2010, Canadian hunters shot another such bear, which turned out to be a second generation hybrid.
Biologists explain that interspecies hybridization happens. True, usually animals of different species do not mate independently, but at the initiative of breeders. Therefore, having met hybrid bears in the wild, scientists were somewhat surprised and worried.
The reason for concern and pseudo-scientific speculation was the fact that since the early 1980s, hybrids of marine animals periodically appear in the polar zone. Brendan Kelly of the National Oceanic and Atmospheric Administration and colleagues at the University of Alaska and the University of Massachusetts believe that increased cross-breeding is another factor. contributing to the extinction of polar bears. The researchers explain that the root cause of interspecific crossing is climate change, as a result of which previously isolated populations begin to share one ecological niche. Natural ice barriers are disappearing, opening the way for interspecies interaction."The more often isolated related species meet each other, the more likely it is that rare animal species and their genomes will join the" common bowl "of dominant species will disappear altogether," biologists write in an article published in Nature.
According to preliminary calculations, up to thirty-four hybrid species may appear in the Arctic in the near future. However, scientists warn against excessive dramatization of the situation. After all, whatever one may say, but interspecific hybridization, as well as warming, is a natural process. Of course, human influence cannot be ruled out. But something similar (a sharp change in the rate of evolution) has already happened in the history of the Earth during the period of the so-called Cambrian explosion.
So far, biologists propose to carry out genetic mapping of Arctic animals, develop a monitoring system for the genetic purity of species and simulate likely scenarios for the development of events. If intervention is required, stop the spread of this or that species outside its range.