Forty years ago this week, a reactor at the Chernobyl Nuclear Power Plant exploded, irradiated a massive swath of Ukraine and Belarus, and forced the evacuation of tens of thousands of people. The land has been largely off-limits ever since. And in the absence of humans, the wildlife moved in and made itself at home.

Among them, gray wolves have done particularly well. Suspiciously well, actually. A 2015 census of animal populations in the zone found that elk, roe deer, red deer, and wild boar were present in numbers roughly comparable to uncontaminated nature reserves nearby. Wolf abundance was more than seven times higher.

Now researchers think they might know why.

Chernobyl’s Radioactive Wolves May Have Evolved a Cancer-Fighting Superpower

A team led by evolutionary biologists Cara Love and Shane Campbell-Staton of Princeton University collected blood samples from wolves inside the exclusion zone, wolves in Belarus, where radiation is lower, and wolves in Yellowstone National Park, where radiation sits at a normal baseline. They found 3,180 genes that behave differently in the Chernobyl wolves compared to the other populations. More specifically, they identified 23 cancer-related genes that are more active in Chernobyl wolves, and these genes are associated with better survival rates for some cancers in humans.

The working theory is that four decades of eating radioactive prey, in a radioactive landscape, across multiple generations, has left a mark on the wolves’ DNA. Whether that mark means they get cancer less, survive it better, or some combination of both, researchers still can’t say for certain.

“There may be genetic variation within the population that may allow some individuals to be more resistant or resilient in the face of that radiation, in which case they may still get cancer at the same rate, but it may not impact their function as much,” Campbell-Staton told NPR. “Or it could be resistance, and despite that radiation exposure, they just don’t get cancer as much.”

Either way, something is happening that shouldn’t be possible under normal circumstances, and scientists are paying close attention.

The exclusion zone covers roughly 4,200 square kilometers across Ukraine and Belarus, and access requires special permission. That enforced isolation has effectively turned one of the worst nuclear disasters in human history into an accidental long-term study in how life adapts when humans disappear and radiation stays.

The paper hasn’t been published in a peer-reviewed journal yet. Campbell-Staton presented the findings at a conference in 2024, and the team is now collaborating with cancer biologists, trying to figure out if any of this has a direct application to human cancer treatment.

Science is catching up. The wolves already figured it out.