How Mutant Wolves Developed a Biological Shield Against Cancer

The post Miracle of Chernobyl: How Mutant Wolves Developed a Cancer-Fighting Bioshield appeared first on AZ Animals.

Quick shot

• Researchers studying gray wolf populations near the site of the Chernobyl nuclear disaster have discovered the evolution of a gene that may protect wolves from cancer.

• The number of wolves in the Chernobyl Exclusion Zone (CEZ) is seven times higher than in nearby areas.

• The wolves in the study were equipped with GPS collars equipped with radiation dosimeters.

• Data shows that wolves are exposed to radiation levels every day that are six times higher than the legal limit for humans.

When the Chernobyl nuclear disaster occurred on April 26, 1986, the area became one of the most contaminated areas on Earth. The 1,000-square-mile area surrounding the abandoned nuclear power plant in northern Ukraine is known as the Chernobyl Exclusion Zone (CEZ). The CEZ is approximately the size of Yosemite National Park in the United States.

The purpose of the CEZ is to limit public access to the area and prevent exposure to the extreme radiation levels that would occur after an explosion. Nearly 116,000 people were evacuated from the CEZ and transferred to other Ukrainian cities.

But wild animals are left to fend for themselves. Now, forty years later, some species have shown the ability to not only survive, but thrive in radioactive environments.

The gray wolf is overcoming the odds

Gray wolves are one of the species that has shown remarkable resistance to the harsh realities of life in the CEZ. As the top predators in the CEZ, gray wolves feed on prey that themselves eat irradiated plants growing in contaminated soil. Scientists expect CEZ wolves to be adversely affected by radiation because their entire food chain is exposed to radiation. But the opposite is true.

A 2024 study published by two Princeton University researchers showed that not only are wolf populations in the CEZ not declining; They are thriving. In fact, their numbers are seven times higher than the wolf population in nearby protected areas outside the CEZ.

What did scientists discover?

Cara Love, an evolutionary biologist and ecotoxicologist at Princeton University, and a team of colleagues have been studying the effects of radiation on wolves in the CEZ since 2014. Using specialized GPS collars equipped with radiation dosimeters, the researchers were able to measure in real time the location of the wolves and the amount of radiation they were exposed to.

The team found that Chernobyl wolves were exposed to more than 11.28 millirem of radiation per day. That’s more than six times the legal safety limit for the average person. Wolves are exposed to these extremes every day of their lives.

So why didn’t the Chernobyl wolves get sick and die from extreme radiation levels?

Love said the team determined that some wolves in the CEZ had altered immune systems, similar to those of patients receiving radiation therapy. The study also identified specific regions of the wolf genome that appear to be resistant to increased cancer risk.

The team believes that long-term radiation exposure may also accelerate natural selection. Wolves that are best able to withstand the effects of radiation live longer and can pass this protection on to their offspring.

That’s not to say that wolves don’t get cancer at all. Love said individual wolves developed cancer at the same rate among the CEZ wolves. Wolves with enhanced immune systems were less affected, allowing them to pass their genes on to their offspring.

The team also believes that the lack of humans in the area may be a reason for the increased population. With threats such as habitat fragmentation, hunting and vehicle collisions all but eliminated in the CEZ, wolf populations there are free to thrive and grow. This factor makes it difficult to directly link wolves’ biological cancer responses to their increased numbers or longevity. Love presented her findings at the 2024 Society for Integrative and Comparative Biology annual meeting.

Are wolves the only species to react this way?

It turns out that gray wolves have similar genetic adaptations to at least one other species studied in the area.

A 2023 study found that dogs in Chernobyl were also undergoing rapid evolutionary changes. The study involved DNA from 302 wild dogs living near the power plant, as well as those living further away. The comparison showed significant genetic differences between the two groups, with Chernobyl dogs better able to withstand the effects of radiation exposure.

Other species have also been observed to rapidly adapt to the unique environment of the CEZ. Przewalski’s horse horses were introduced a few years after the explosion as a conservation experiment. Although scientists have not yet studied them specifically to identify genetic changes, their populations are thriving.

Eastern tree frogs have also evolved in more obvious ways. Their natural color has changed from bright green to nearly black. Scientists speculate that darker skin tones may provide better protection against radiation. The darker frog is now known as the Chernobyl black frog.

However, gray wolves are the species that offer the most hope to Love and her colleagues involved in human cancer research.

What are the implications for human cancer research?

Love and her team are now working with cancer experts to determine whether findings from wolf genetic adaptations can help guide future treatments for humans. While the link remains speculative, Love’s research is helping human cancer scientists understand how extreme environments impact disease resistance.

The post Miracle of Chernobyl: How Mutant Wolves Developed a Cancer-Fighting Bioshield appeared first on AZ Animals.