Thriving Amid Radiation: The Genetic Secrets of Chernobyl Wolves
In the spring of 1986, a meltdown in reactor four at the Chernobyl nuclear power plant in Ukraine (part of the Union of Soviet Socialist Republics at the time) caused a fire and explosion, releasing radiation into the surrounding environment. Several workers died, and nearly a hundred thousand people were evacuated from the area. In the wake of the event, increased genetic mutation was observed in humans, plants, and animals in the area.
However, the expanding gray wolf population in the Chernobyl Exclusion Zone (CEZ), which includes parts of Ukraine and Belarus, has recently drawn significant scientific attention. Their numbers are high, raising questions that are still being answered: Are they evolving resistance to radiation or simply better off without humans around?
Wolf Population Surge in Belarus
In spite of the ongoing radiation exposure, the area around Chernobyl is witnessing an increase in formerly rare species such as wolves, moose, wild boar, beavers, and more, with gray wolves being the most abundant.
A study published in Current Biology shows that, by the mid-1990s, wolves in the Belarusian part of the exclusion zone had become so abundant that they were causing trouble for farmers. In additon, the wolf density in the Belarus sector of the Polessye State Radioecological Reserve was found to be seven times higher than before the power plant meltdown.
How Did Chernobyl Wolves Thrive in the Face of Radiation?
In 2024, Cara Love, an evolutionary biologist and postdoctoral fellow at Princeton University, led a study on wolves in the Chernobyl Exclusion Zone to understand their adaptation to radiation. The team collected blood samples and fitted the wolves with GPS collars and radiation dosimeters. The scientists discovered that the wolves endure 11.28 millirem of radiation daily, which is six times the human safety limit. But the wolf population has grown anyway.
Love and her colleague Shane Campbell-Staton hypothesize that one of two things is happening. Either the wolves are developing cancer in response to the environmental radiation, but the cancer isn’t impacting their functioning the way it would in an animal outside of the CEZ or the wolves aren’t developing cancer despite the presence of radiation. Wolves with genes that are more resistant to cancer are the ones procreating and passing on a genetic resistance to radiation.
The immune systems of wolves resemble those of cancer patients receiving radiation therapy. A study published by Love on the wolves in Chernobyl pinpointed specific cancer-resistant regions in the wolves’ genomes, highlighting the role of genetic mutations and natural selection. However, natural selection may not be the only reason for an increase in their population; the absence of humans in the abandoned area may also be a contributing factor.
Wolves vs. Radiation: Uncovering Nature’s Survival Secrets
In February 2024, Love and Campbell-Staton were featured on the NPR science podcast Short Wave. During the podcast, Love said, “By counting the number of different immune cells within an individual, we’re able to identify some signature of radiation stress within the Chernobyl wolves. And we’ve also explored many different parasite and pathogen infections within this population compared to reference populations, trying to get at disease rates.”
Campbell-Staton, who is a fellow evolutionary biologist at Princeton, added on the NPR podcast, “What we were interested in is trying to identify regions of the genome that seem to be diverging much faster in Chernobyl than they are elsewhere.” Additionally, wolves may thrive better without human hunting despite the threat of cancer. Campbell-Stanton pointed out, “The other thing is, humans aren’t there, right? A wolf within the Chernobyl Exclusion Zone—it may have to deal with pressures from cancer, but it doesn’t have to deal with pressures from, say, hunting.”
An Interrupted Journey to Find Answers
Love and Campbell-Staton’s innovative research on Chernobyl wolves has important implications for human health. Campbell-Staton revealed that their team has begun collaborating with cancer biologists and companies to interpret the data, aiming to discover new therapeutic targets for human cancer. Unfortunately, their research has faced significant setbacks. Initially halted by the COVID-19 pandemic, it is now further disrupted by the ongoing conflict between Russia and Ukraine.
Despite these challenges, the potential insights acquired from the wolves’ unique genetic adaptations remain invaluable. The rapid genomic evolution of wolves in Chernobyl could pave the way for innovative cancer treatments, such as targeted therapies or radiation resistance. As the world watches, the hope is that this research will resume and continue to unlock secrets that could reform human health. The resilience of these wolves may inspire breakthroughs in combating cancer.
Joisey Thekkumpuram Jojan is a Thermo Fisher Scientific staff writer.