Almost four decades have passed since the accident at the Chernobyl nuclear power plant, but the territory around the station continues to be the subject of special attention from the researchers.
During this time, the exclusion area has become a kind of natural reserve, where animals demonstrate unique adaptations to extreme conditions. According to RIA Novosti, recent research has shown that some species living in this region show signs of accelerated evolution.
A team of Spanish researchers from the University of Oviedo, led by Herman Orizola, studied the arboric frogs (also known as singers) in the exclusion area. They found that the skin of these amphibians has changed significantly as a shade. If normally the frogs have an intense green color, in the chernobyl they have become much darker, until black. Scientists link this to the high level of melanin – pigment that protects the body from the harmful effects of radiation. It is assumed that darker skin frogs had higher chances of survival, and this feature has been transmitted to the following generations.
Besides the amphibians, the researchers also analyzed the round worms – non -states. The biology professor at the University of New York, Matthew Rockman, together with his team, found that the nematodes collected from the radioactive contaminated areas do not show signs of genetic deterioration. They either adapted to the increased radiation level, or had from the beginning protective mechanisms against mutations.
Another special discovery is related to the wolves in Chernobyl. Biologists from Princeton University have been studying them since 2014, monitoring their movements and radiation reaction. It has been found that these predators are exposed to a radiation level more than six times higher than the limit considered safe for people. However, their immune system has developed a resistance to possible damages, including cancer. The phenomenon is not yet fully understood, but it has a major potential for medical research.
Similar studies were also conducted on dogs living in the exclusion area. A team led by Timothy Mousseau analyzed the DNA of over 300 copies and identified significant genetic differences from domestic dogs living in less contaminated regions. For now, it is not clear what types of mutations have occurred and how they influenced their physiology, but this is another example of how radiation influences evolutionary processes.
The adaptation was also observed among the birds in the exclusion area. An international team of researchers, also led by Timothy Mousseau, found that the birds exposed to radiation have a higher level of antioxidants, which helps them to protect themselves more efficiently from environmental stress and can increase their chances of survival in extreme conditions.
However, not all species have adapted with the same success. In the first years after the catastrophe, there have been numerous mutations in domestic animals, especially in cattle and pigs. Between 1989–1990, a sudden increase in cases of genetic abnormalities, including defects of the limbs, facial malformations and pigmentation changes. Many of these animals could not survive, and their milk and meat were contaminated with radioactive substances.
