Chornobyl dogs show signs of natural selection in polluted environment

New research published in the journal Genes suggests that dogs living near the Chornobyl Nuclear Power Plant are undergoing natural selection rather than simply accumulating radiation-induced mutations. A team led by North Carolina State University analyzed the genomes of 106 free-breeding dogs to understand why the population near the plant differs significantly from dogs living in Chornobyl City, located 16 kilometers away.

The study investigated whether these genetic differences were caused by genetic drift, a process of random change in isolated populations, or directional selection. By comparing the Chornobyl populations with other free-breeding dogs in Eastern Europe and an isolated population from the Galápagos Islands, researchers found that the plant population did not show the broad reduction in genetic variation expected from genetic drift.

Instead, scientists identified signs of selection at more than 100 locations in the genome. These specific regions are associated with critical biological processes, including DNA repair, immune system activity, cell cycle regulation, and cancer-related pathways. While researchers noted that the environment may not have created new mutations, individuals with pre-existing genetic variants that aided survival in a contaminated environment likely became more common over generations.