Over 35 years ago, the world's worst nuclear accident near Chernobyl, Ukraine (then part of Soviet Russia) forced thousands of its residents to flee the site overnight. Locals left everything behind, some even had to abandon their pets.
Now, recent research is focusing on the descendants of these pets left behind to examine how living in a radioactive environment changed them. It also tries to find out what it is like to survive and breed in one of the most degraded environments.
The research, which is still ongoing, can answer what it may be like for humans to survive and live in a radioactive environment.
A report published on March 3 in the journal Science Advances looked at the genetic makeup of 302 stray dogs called "free-roaming dog populations" of Chernobyl.
They compared the genetic structure of dogs living within the power plant and those living 15-45 km away.
Scientists found that dogs living within the nearly 30 km exclusion zone were "genetically distinct" from those living further away from the epicenter.
The Chernobyl exclusion zone is where the radioactive contamination is the highest and public access is restricted and habitation not allowed.
Geneticist Elaine Ostrander one of the study's authors said that the dogs provided a "golden opportunity to answer:
How do you survive in a hostile environment like this for 15 generations?
- Elaine Ostrander, author
While the research has found the dogs living near the main contamination site to be genetically different from those living further away and the dogs around the world at large, it is not yet confirmed whether radiation is to blame for the changes.
The research is yet to find out what changed in the DNA of the dogs of Chernobyl and how it matters.
We can compare them and we can say: OK, what's different, what's changed, what's mutated, what's evolved, what helps you, what hurts you at the DNA level?
- Elaine Ostrander, author
Researchers also compared the DNA analysis of the Chernobyl dogs with the DNA of stray dogs in Eastern Europe.
They found that the dogs of Chernobyl are not newcomers and have been isolated from other dog populations for decades.
When emergency workers culled several of the canines in the immediate aftermath of the accident, it was due to the concern that the dogs would migrate and spread the contamination. However, the dogs don't seem to have migrated.
Ostrander also that they were expecting to not see much changes in the DNA samples of the dogs given how long they have intermingled over 35 years.
But researchers were able to identify dogs living in areas with high, low, and medium levels of radiation with their DNA and even families - 15 of them.
When the dogs, mostly pets, were left behind at the disaster site, many died as a result of the radiation, and others were culled by emergency workers to stop the spread of contamination.
But some managed to survive. They managed to live in the highly contaminated zones and even reproduce for generations.
They were also driven out of remote areas by the wild wolves, forcing them to stay near the nuclear plant.
The Chernobyl site today in Ukraine is not a complete ghost town, despite the apartments and residences still frozen in time to April 26, 1986.
The site is occupied by some 3,500 workers. The dogs have relied on the workers to get scraps of food and survive.
Many are however exposed to rabies and programs are underway to spay and sterilize the dogs.
There are an estimated 900 stray dogs living in the exclusion zone and several more living in the Chernobyl city.
Research at Chernobyl is continuing despite the Ukraine-Russia war. Fellow author of the study Tim Mousseau who has been to the site multiple times to collect the blood samples of the dogs says that he didn't encounter any war-related event during his visit last October.