Biologists Germán Orizaola from the University of Oviedo and Pablo Burraco visited the Chernobyl exclusion zone
Radiation can damage genetic materialliving organisms and cause unwanted mutations. However, one of the most interesting research topics in Chernobyl – this is an attempt to determine whether some species actually adapt to living in radiation environments, the researchers write. As with other pollutants, radiation can be a very strong selective factor, favoring organisms with mechanisms that increase their survival in areas contaminated with radioactive substances.
In 2016, not far from the damaged nuclearreactor they found several eastern tree frogs (Hyla orientalis) with an unusual black tint. This species usually has a bright green dorsal coloration, although darker specimens are occasionally seen.
Melanin is responsible for the dark color of many organisms.Less well known is that this class of pigments can also reduce the negative effects of ultraviolet radiation. Its protective role may also extend to ionizing radiation, as has been shown in mushrooms. Melanin absorbs and dissipates part of the radiation energy. In addition, it can absorb and neutralize ionized molecules within the cell, such as reactive oxygen species. These actions reduce the likelihood of cell damage in people exposed to radiation and increase their chances of survival.
Scientists have found that the Chernobyl eastern tree frogs are much darker in color than the frogs caught in the control plots outside the zone, some of them are completely black.
“The results of our study allowto suggest that the Chernobyl frogs could have undergone a process of rapid evolution in response to radiation. Under such a scenario, those frogs that were darker in color at the time of the accident and usually constituted a minority in the population would benefit from the protective action of melanin,” the biologists write.