In 1986, the Chernobyl Nuclear Reactor in northern Ukraine, which was part of the Soviet Union at the time, had an explosion that caused a huge radiation plume in the sky. Up to this day, the Chernobyl Power Plant and several regions in its vicinity are still unoccupied by humans.
Since humans evacuated the area after the Chernobyl disaster in 1986, various types of animals have been thriving in the region. The radiation-resistant fauna include many feral dogs, which are descendants of the pets left behind during the evacuation.
As the disaster nears its 40th anniversary, scientists are studying the animals in the Chernobyl Exclusion Zone (CEZ), an area about the same size as Yosemite National Park. They aim to determine how years of exposure to radiation have affected the animals’ genomes and whether this has led to a faster pace of evolution.
Researchers from the National Human Genome Research Institute and the University of South Carolina have started analyzing the DNA of around 302 feral dogs found in the Chernobyl Exclusion Zone and its surrounding areas. The aim of the study is to determine how the radiation from the nuclear disaster may have affected the dogs’ genomes. The results of their research were recently published in the Science Advances journal.
Elaine Ostrander, co-author of the study and an expert in dog genomics at the National Human Genome Research Institute, questioned whether the feral dogs in the CEZ have acquired mutations that help them survive and reproduce in the area, and what genetic adaptations they have developed to cope with the challenges they face.
The concept of radiation accelerating natural evolution is not a novel one. For instance, the strategy of intentionally exposing seeds to radiation in space to cause favorable mutations has become a common method for creating crops that can thrive in a changing climate.
Researchers have been studying animals within the Chernobyl Exclusion Zone for several years, such as bacteria, rodents, and birds. In a 2016 study, it was discovered that Eastern tree frogs within the zone were mostly black instead of their usual green color. Biologists suggest that these frogs may have undergone a useful mutation in their melanin pigments that helped them cope with the radiation present in their environment.
Scientists began to consider if a similar phenomenon is occurring with the feral dogs of Chernobyl.
The recently conducted study revealed that there are genetic variations between the feral dogs found near the Chernobyl Power Plant and those living in Chernobyl City, located about 10 miles away. Though this may suggest that the dogs have undergone rapid mutation or evolution due to radiation exposure, the study is just the initial step to prove this hypothesis. According to an environmental scientist interviewed by Science News, it can be challenging to distinguish mutations caused by radiation from other factors such as inbreeding.
Despite the current lack of clear evidence, this study has set a model for further exploration of the effects of radiation on larger mammals by comparing the DNA of dogs living in irradiated areas with that of dogs in non-irradiated areas. It is noteworthy that this area that should be barren provides an extraordinary opportunity for scientists to learn more about radiation and its impact on natural evolution.
Read More: Popular Mechanics