A study published in the journal Canine Medicine and Genetics revealed significant genetic differences among stray dogs inhabiting the Chernobyl Exclusion Zone (CEZ). Researchers collected blood samples from 116 semi-feral dogs living around the Chernobyl nuclear power plant and the nearby city of Chernobyl. Led by environmental health scientist Dr. Norman J. Kleiman from Columbia University, the team aimed to understand how chronic exposure to radiation and other environmental hazards has impacted these canine populations.
According to the study, the dogs were divided into two main groups based on their proximity to the nuclear reactor and the city, located approximately 16 kilometers apart. DNA analysis showed that these populations are genetically distinct and have low rates of interpopulation migration. "Somehow, two small populations of dogs managed to survive in that highly toxic environment," Dr. Kleiman stated, as reported by Enikos. The research identified nearly 400 genomic regions, or "outlier loci," that exhibited significant differences between the two groups.
"Understanding how these dogs have adapted can provide insights applicable to human health, especially for those exposed to similar environmental hazards," Dr. Matthew Breen from North Carolina State University said, according to a report by The Independent. The study found that some of the genetic markers are associated with DNA repair mechanisms, suggesting an enhanced ability to cope with environmental stressors.
The Chernobyl disaster of April 26, 1986, remains the world's most catastrophic nuclear incident. The explosion at the reactor released radioactive material estimated to be nearly 200 times greater than that of the atomic bombs dropped on Hiroshima and Nagasaki combined. This led to the evacuation of residents from the CEZ, resulting in abandoned pets whose descendants now roam the area. It is estimated that approximately 900 stray dogs live in the region, many likely descendants of pets left behind after the mass evacuation.
Despite the highly toxic environment, these dogs have managed to survive and adapt over generations. The research suggests that mutations caused by chronic exposure to radiation and other hazardous substances have been passed down from parent to offspring.
Scientists are particularly interested in how these adaptations may shed light on the health impacts of living in highly toxic environments. "Understanding the genetic and health impacts of these chronic exposures in the dogs will strengthen our broader understanding of how these types of environmental hazards can impact humans and how best to mitigate health risks," Dr. Kleiman said, according to Mirror.
The study also noted that the dogs have formed unusual packs and live closer together than wild dogs or wolves typically do. They show social structures akin to domestic dog behavior but with adaptations to their harsh environment, including foraging through abandoned buildings and scavenging leftovers from the few individuals who venture near. Some have established friendly bonds with scientists and workers who are still active in the area.
Previous research in the CEZ has shown similar phenomena of adaptation in other species. For instance, Eastern tree frogs near the Chernobyl site have changed from their original green color to a darker black skin, likely due to a mutation in melanin that may help neutralize radiation. According to Enikos, these adaptations may have allowed them to survive in the contaminated environment.
While the findings do not definitively prove that radiation is the cause of these genetic differences, they offer clues about the long-term effects of living in a radioactive environment. Researchers pointed out that the study was correlational and does not provide direct evidence that mutation was the game-changing force.
This article was written in collaboration with generative AI company Alchemiq