Did you know that dogs living in the Chernobyl Exclusion Zone are genetically distinct? According to a recent study, these furry creatures have been roaming among the decaying concrete buildings and surrounding forests of what is now essentially one of Europe's largest nature reserves. Nearly 40 years ago, the world's worst nuclear disaster turned the Ukrainian city of Pripyat and its nearby power plant, Chernobyl, into a radioactive hot zone – but surprisingly, decades later, it has become a haven for wildlife.
Wolves, wild horses, birds, bison, elk, frogs, and dogs can be found in this area. While humans fled the contaminated zone, plants grew, and animals moved in. Scientists have long wondered what effects decades of exposure to low-dose radiation may have had on the area's wildlife. Some studies have pointed to sharp declines in bird populations, while others have found little evidence of such radiation effects. However, by characterizing distinct populations of dogs that live in and around Chernobyl through genetic analysis conducted by an international team of researchers, this latest study provides a better basis for comparing changes in the species. Large mammals such as dogs and horses are of particular interest because their health could enlighten us as to what might happen when humans eventually return.
Despite the radioactivity from the area known as the Chernobyl Exclusion Zone extending some 2,600 square kilometers (about 1,000 square miles) around the ruinous power plant where radiation continues to emanate from even today almost four decades later since the disaster occurred; feral dog numbers have been rising. The formation of Chernobyl Dog Research Initiative (CDRI) provided veterinary care for these dogs since 2017. More than 800 dogs are estimated to be living in and around Chernobyl often fed by power plant workers who return to maintain the facility. Comparative analyses showed that not only were these Chernobyl dogs genetically distinct from free-breeding dogs in Eastern Europe Asia and Middle East but they also revealed a surprising amount of genetic overlap and kinship ties between them despite existing in three distinct populations.
This messy natural experiment could still be hugely useful for improving our understanding of how radiation affects biology. The next step will be designing broader studies "aimed at finding critical genetic variants that have accumulated for more than 30 years in this hostile contaminated environment."