On April 26, 1986, a system test at the number four RBMK reactor at the Chernobyl plant in Ukraine led to the reactor overheating and causing a series of disastrous explosions, leading to the world’s worst nuclear disaster.
The Soviet military quickly established a ‘Chernobyl Exclusion Zone’ around the plant – a 30-mile cordon that the public could not access due to contamination, and which remains largely abandoned today, a haven for wildlife, from wild dogs to wild horses.
But what effect has radiation from ‘The Zone’ – an area the size of Yosemite National Park – had on the wildlife that now thrives there?
Several animals are beginning to show differences from those elsewhere, scientists say – and some are displaying what might be described as ‘superpowers’.
Nature thrives in the shadow of the Chernobyl factory
The destroyed Chernobyl factory
The background radiation is up to 100 times higher than that of the nearby, pristine city of Kiev, but scientists are still debating how much effect the radiation has had (compared to other factors such as the absence of people).
However, The Zone is safe for humans to walk through, and is even visited by tourists (and people still work at the Chernobyl nuclear power plant, much of it on cleanup duties).
Tourists are being warned that off-the-beaten-track ‘hotspots’ still harbor dangerous levels of radiation – and are being told not to eat the fish and mushrooms that thrive in the wild landscape near Kiev, Ukraine.
In the aftermath of the accident, the plant itself remained open and other reactors generated up to 2,000 electricity.
The black frogs of Chernobyl
Frogs around the destroyed nuclear power plant have darkened – a response, researchers believe, to radiation hotspots in ‘The Zone’.
The frogs around ‘The Zone’ have become darker due to the radiation
Researchers believe the amphibians quickly developed black skin because green frogs were less likely to survive – which the researchers described as “rapid evolution.”
The eastern tree frogs with the most protective melanin pigment were most likely to survive in highly radioactive areas, meaning populations were dominated by darker frogs.
The researchers believe that the period of “rapid evolution” may have occurred just after the accident itself, when radiation levels were at their highest, the team led by Pablo Burracco wrote in their study.
The radiation makes the frogs darker, the researchers think
The researchers wrote on The Conversation in 2016: ‘Our work shows that Chernobyl tree frogs have a much darker color than frogs captured in control areas outside the zone.
‘As we discovered in 2016, some are pitch black. This coloration is not related to the radiation levels that frogs experience today and that we can measure in all individuals.
‘The dark color is typical of frogs that were in or near the most polluted areas at the time of the accident.’
Super powerful bacteria
Bacteria found on the wings of swallows in Chernobyl appear to be more resistant to the effects of gamma radiation.
When exposed to doses of radiation, bacteria from Chernobyl were able to reproduce and thrive, compared to bacteria from elsewhere.
Bacteria found on the wings of birds near the site are radiation resistant
In a 2016 study published in Scientific Reports, the researchers wrote: “Long-term effects of radiation in natural populations may exert important selective pressure on traits of bacteria that facilitate survival in certain environments.”
Cancer-resistant wolves
Mutated wolves roaming the Chernobyl wasteland have developed a kind of ‘superpower’ – one that could save human lives.
Researchers discovered that the animals in the Chernobyl Evacuation Zone (CEZ) have a genetically altered immune system that shows resilience against cancer.
Wolf tracks near Chernobyl
Researchers are now trying to find out whether the genes can help human cancer patients.
In 2014, Cara Love, an evolutionary biologist at Princeton University, traveled to The Zone with a team of researchers to understand how animals were able to survive cancer-causing radiation.
Researcher Cara Love with a wolf at Chernobyl
Love and her team took blood samples from the wolves and placed GPS collars with radiation dosimeters to get real-time readings of where they were and their radiation exposure levels.
“We’re getting real-time measurements of where they are and how much (radiation) they’re exposed to,” Love said.
The researchers examined the genetic differences between the DNA of mutated wolves within the 1,000 square kilometer radius of the CEZ and those outside it.
Analysis showed that some of their cancer-related genes had new mutations, suggesting they evolved to protect against the radiation.
It is hoped the discovery could pave the way for experts to identify mutations in people that reduce the risk of cancer.
A new kind of dog?
There are now thousands of wild dogs living in ‘The Zone’, many of whom are descended from pets left behind when people fled the area in the aftermath of the 1986 disaster.
A study by scientists at the University of South Carolina analyzed the DNA of 302 wild dogs near the power plant and found significant DNA differences from other dog populations.
A tawny owl flies out of a chimney near Chernobyl
The researchers write: ‘the individuals from the power plant and the city of Chernobyl are genetically different’.
More research will reveal how much radiation contributed to the genetic differences (compared to other factors such as inbreeding).
Co-author Elaine Ostrander, a canine genomics expert at the National Human Genome Research Institute, told the New York Times, “Do they have mutations that they’ve acquired that allow them to live and breed successfully in this region?”
‘What challenges do they face and how have they genetically dealt with them?’