Radiation in the Chernobyl Exclusion Zone caused mutated frogs. The green frogs died and the totally black ones survived.
Over the 36 years after the Chernobyl nuclear accident, the tree frogs, typical of the place, have changed color. The exclusion zone caused them to go from a bright, intense green color to a completely dark shade.
It was one of the worst nuclear disasters in history.
The accident in northern Ukraine, then under Soviet rule, released large amounts of cesium-137. It was the biggest environmental disaster in human history. The radioactive material has spread across most of Ukraine, and even Norway and the UK. Nearly four decades later, its consequences remain to be discovered.
Currently, the exclusion zone, which covers 2,600 square kilometers, has become a huge nature reserve that is home to many species. Scientists use this area to investigate how animals can adapt to these extremely high levels of radiation in their environment.
One of the recent discoveries is the remarkable transformation of the local tree frogs from bright green to black.
Black color mutant frogs to survive
According to the researchers of the study published in the journal Evolutionary Applications, the darker frogs were more likely to survive when the disaster struck in 1986, making them more numerous today.
Thus, in the evolutionary effort for survival, this dark coloration may not exactly be the result of genetic mutations caused by radiation contamination, but it may be due to frogs that had darker skin coloration at the time of the accident, which are normally a minority within their species. populations, survive longer due to the protective effects of melanin.
More than ten generations of frogs have lived and died since the accident, suggesting that a very rapid process of natural selection may explain why the predominant frogs are now black (because radiation kills off the bright green ones).
And what does the color black do to make them more resistant?
The pigment that darkens the skin of animals, melanin, works to reduce cell damage caused by radiation. This means that people with darker skin will be less likely to experience cell damage after exposure to radiation, for example.
Another proof of the recovery of ecosystems from disasters as imposing as this one.
RReference: Ionizing radiation and melanism in Chornobyl frogs
Pablo Burraco, German Orizaola
First published: August 29, 2022 Evolutionary apps