Evolution is generally considered to be quite a slow, clunky process. However, dogs living in the Chernobyl nuclear power plant have undergone rapid evolution in the forty years since the disaster.
In a study IFLScience reported on earlier this year, researchers analyzing blood samples from dogs roaming the power plant with those in surrounding areas discovered that those closest to the site of the explosion displayed differences in their DNA that show they are genetically distinct from dogs in the rest of the world.
“I think the most remarkable think about the study is that we identify populations of dogs living in and in the shadow of the reactor, and we can tell who those dogs are just by looking at their DNA profile,” Elaine Ostrander, study author and geneticist at the NIH’s National Human Genome Research Institute, told IFLScience at the time.
At this point in time, it is unclear how exactly these genetic differences impact the health and characteristics of these hardy canines. However, they are not the only species to have seemingly evolved in the wake of the disaster. More recent research examining the genetics of wolves in the area suggests that they have developed protection against cancer. Another study found tree frogs living in the Exclusion Zone are much darker than those living outside. This particular adaptation may have reduced the negative impacts of radiation exposure by providing the darker-colored frogs with higher levels of melanin.
Why is this happening? While the study itself does not explain why it is that the dogs of Chernobyl are genetically different to their brothers and sisters living in other, less radioactive areas of the world, there are a number of ways radiation can impact populations of animals.
One possible reason explained in a 2020 study is that radiation can cause mutations, which contribute to genetic variation that is passed from parent to child. A further explanation is that those individuals unable to cope with the impact of exposure to radioactivity will die off, leaving a population better suited to their new surroundings. This has the opposite effect of reducing genetic variation.
In 2022, researchers measured genetic diversity in a species of water flea that inhabit lakes in the Chernobyl area and found that levels of genetic diversity were higher in those lakes that received greater levels of radiation. This suggests – in this case, at least – that mutation was the primary evolutionary force affecting the genes of the aquatic bug. However, as the researchers themselves were keen to point out, the study was correlational and not causational, and so does not provide direct evidence that mutation was the game changing force. Equally, it does not mean the same processes occurred in populations of local dogs.
What is clear is that the genetic changes observed in the Chernobyl pups demonstrate the surprisingly swift evolutionary processes that can occur in populations affected by environmental change and there is much more to unpack.
