The Chernobyl Nuclear Reactor in northern Ukraine—then part of the Soviet Union—exploded on April 26, 1986, spewing radiation into the sky. Nearly four decades later, the Chernobyl Power Plant and much of the surrounding area are still unoccupied by people.
Without humans, all animals have prospered. Thousands of wild canines, many of them are offspring of pets abandoned during the rapid evacuation, live among radiation-resistant animals.
As the world's worst nuclear disaster approaches its 40th anniversary, biologists are studying animals in the Chernobyl Exclusion Zone (CEZ), about the size of Yosemite National Park, to determine how decades of radiation exposure may have altered their genomes and sped up evolution.
The University of South Carolina and the National Human Genome Research Institute are studying 302 wild canines from the CEZ to see how radiation affected their genomes. Science Advances reported their findings last month.
“Do they have mutations that let them live and breed here?” dog genetics specialist told. “How have they genetically coped?”
Radiation accelerates evolution. Developing crops for a warmer planet involves irradiating seeds in space to promote beneficial mutations.
For years, scientists have studied CEZ bacteria, rats, and birds. Eastern tree frogs (Hyla orientalis), generally green, were more black in the CEZ, according to a 2016 research. The experts believe the frogs' melanin mutation ionized radiation.
This recent study found genetic variations between wild canines near the Chernobyl Power Plant and those 10 kilometres distant in Chernobyl City. This study is merely the first step in establishing that radiation exposure caused these canines to rapidly evolve.
One environmental expert told Science News that radiation-induced mutations are hard to distinguish from other consequences like inbreeding, making these research challenging.
This work may be used to evaluate the effects of radiation on bigger mammals by comparing the DNA of dogs from the Chernobyl Power Plant and neighboring Chernobyl City to dogs from non-irradiated locations.
The study has proved again that a place that should be a wasteland has become a unique scientific opportunity to investigate radiation and natural evolution.