Collars on wolves in Chernobyl’s exclusion zone were programmed to record their location and radiation readings every 35 minutes. The paired measurements let researchers follow the animals’ exposure as they moved through contaminated terrain.

Blood samples from the same research effort have pointed toward another question: could inherited differences help these wolves cope with radiation? Some of the genetic leads involve immune processes that also interest cancer researchers.

A study published in Molecular Ecology on April 28, 2026, led by evolutionary biologist Cara Love, brings together evidence of biological stress and possible adaptation. It gives researchers specific genetic candidates to investigate.

The fieldwork took place in Belarus’s Polesye State Radiation Ecological Reserve, within the wider exclusion zone created after the April 26, 1986, nuclear disaster. Wolves receive radiation from their surroundings and from radioactive material they take in through food and water.

For a roaming predator, exposure changes with location. Contamination can vary between patches of habitat, so two wolves using different parts of the same region may receive different doses. Attaching radiation monitors to GPS collars helped the team measure that variation instead of relying on readings from the places where animals were caught.

Researchers had already documented a striking population pattern. A 2015 study in Current Biology used winter surveys to compare the Belarusian exclusion-zone reserve with four uncontaminated Belarusian reserves. It estimated wolf density was more than seven times as high in the contaminated reserve.

The evacuation had removed many of the activities that restrict wildlife, including farming, forestry and hunting. Human pressures on wolf populations can change sharply across a protected area’s boundary. Within the exclusion zone, reduced disturbance offered wolves an advantage even as contamination persisted.

“This doesn’t mean radiation is good for wildlife,” University of Portsmouth environmental scientist Jim Smith said when the 2015 findings were released. The abundance figures described a population; they left open questions about the health of individual animals.

The wolves could also move beyond the contaminated area. In February 2015, a collared young male left the zone and reached a point about 229 miles, or 369 kilometers, from its former home-range center. Researchers documented the movement in a 2018 paper.

Such journeys connect populations. Wolves that disperse and reproduce elsewhere can pass inherited variants to new generations outside their original territory. To understand genetic differences within the exclusion zone, scientists have to consider migration and ancestry alongside local environmental pressures.

Where the cancer clues begin

Love’s team collected blood from 11 exclusion-zone wolves in 2014 and 2016. Different analyses drew comparisons with wolves from northern Belarus and existing Yellowstone data. From blood RNA, computational estimates indicated fewer T and B cells, proportionally, and more granulocytes and monocytes than in the Belarus reference group.

Those shifts were consistent with immune stress. Genetic analyses also highlighted one signal within APBB1IP and two near EMC6, genes connected in other research to immune behavior and cancer biology. The nearby signals could affect other genes, too.

These findings bring two timescales into the investigation. An animal’s immune activity can change during its lifetime in response to its surroundings. Natural selection works across generations: an inherited variant that helps an animal survive and reproduce may become more common in its descendants.

Useful variation may already exist in a population before conditions change. If chronic radiation favors particular inherited traits, selection could increase their frequency. Establishing that process in wild animals requires separating it from chance shifts in gene frequencies and the arrival of wolves from other populations.

The study didn’t measure cancer incidence or show that the candidate variants protect wolves from tumors. Its genetic signals identify possibilities for testing. Researchers studying Jonathan the tortoise’s DNA face a similar challenge: connecting an unusual genetic pattern with a demonstrated effect on cellular health.

A gene can influence several processes, and a change that helps in one setting may carry a cost in another. Immune systems have to respond to infections, damaged tissue and abnormal cells while regulating their own activity. Understanding a candidate variant means finding out which of those tasks it changes, and under what conditions.

Love’s broader project includes work with university and industry cancer researchers to explore whether wildlife responses to contamination could inform human health research. The questions include possible adaptations, the costs of prolonged exposure and whether any useful biology could apply across species.

That work calls for experiments connecting a wolf’s DNA to what happens inside its cells. If a candidate variant changes the response to radiation, researchers can investigate how it works and whether it affects disease risk. The collars helped establish what the animals encountered. The next challenge is to discover what their cells can withstand, and why.