Dogs living near the Chernobyl Nuclear Power Plant show genetic differences from nearby populations, with new research suggesting natural selection—not radiation-induced mutations—may explain the divergence, according to a study published in Genes.
Researchers analyzing 106 dogs from the Chernobyl Exclusion Zone (CEZ) found genetic variations concentrated near genes linked to cancer, immune response, and cellular repair. These changes suggest adaptation to the area’s toxic environment. The study, led by population geneticist Megan Dillon of North Carolina State University, builds on earlier work ruling out mutations as the primary cause of differences between dogs near the plant and those 16 kilometers away in Chornobyl City.
Natural Selection Drives Genetic Changes
The team’s analysis of whole-genome data from 2018–2019 revealed changes in genomic regions linked to survival in contaminated environments. Mutations were discounted as the driving force. Instead, the findings suggest natural selection favored traits aiding resilience to radiation and toxic exposure. These genomic signatures are suggestive of selection,
Dillon said, noting the genes involved in pathways like DNA repair and immune function.
Matthew Breen emphasized that the dogs’ genetic diversity likely predated the 1986 disaster. The consequence may not have gone as far as changing the dogs’ genome to adapt,
he said. The zone may have favored certain dogs that were already there.
The study’s authors caution that while directional selection is plausible, further research is needed to confirm the mechanism.
A 2023 study analyzed dogs in the CEZ and found genetic distinctions between populations near the nuclear plant and those in Chornobyl City, about 16 kilometers away. A 2024 follow-up study found no evidence that mutations drove these differences, prompting the new research to explore alternative explanations.
Debate Over Mutation Effects
A separate 2023 study of dogs in the CEZ found genetic distinctions between populations, leading to discussion over whether radiation caused harmful mutations. A 2026 article from BGNES raised concerns that Chernobyl dogs relocated elsewhere could pass these mutations to future generations. The puppies in question were sterilized to prevent reproduction. Timothy Mousseau, a co-author of the study, warned of adverse consequences
if such mutations persisted.
The new research focuses on the CEZ’s isolated dog populations. Comparisons with geographically distant groups, including an isolated Galápagos Islands population, showed the Chernobyl dogs’ genetic differences were not due to random drift. The NPP population did not show evidence of reduced genetic variation consistent with genetic drift,
the study noted, reinforcing the selection hypothesis.
Scientists also examined the impact of the 1986 disaster, which displaced nearly 116,000 people and left animals to thrive in the abandoned zone. Dogs in the CEZ, now more than 30 generations removed from the event, have become a focal point for studying long-term ecological effects. We used a very detailed analysis and found signatures of selection in biologically relevant regions,
Dillon said.
Insights Into Ecological Adaptation
The findings offer insights into how wildlife adapts to chronic contamination. The dogs, now more than 30 generations removed from the 1986 disaster, provide a rare opportunity to study long-term genetic shifts in a controlled, isolated environment. This work ties up some of the loose ends from our previous work,
Dillon said, highlighting the importance of understanding evolutionary drivers in extreme conditions.
Can Chernobyl Dogs Pass Genetic Mutations to Future Generations?https://t.co/8vIjeS4DQi pic.twitter.com/BgHAMUJ2ue
The study’s authors stress that while the dogs’ genomes show signs of adaptation, they do not claim the animals are healthier. The result is a single study based on genome data from 106 dogs,
the team wrote, emphasizing the need for further investigation. The research highlights the complex interplay between environmental stressors and genetic diversity, with potential applications for managing wildlife in polluted regions.
Additional context from the sources includes the 2,600-square-kilometer exclusion zone, the 16-kilometer distance between the nuclear plant and Chornobyl City, and the New Safe Confinement Structure housing the damaged reactor. The study’s methodology involved whole-genome sequencing of 106 dogs collected between 2018 and 2019, with results published in the journal Genes. Researchers from North Carolina State University contributed to the work.