What can the animal kingdom teach us about tackling cancer?

When we face major challenges, our instinct is to look inward. We study our own biology, develop new technologies, and search for answers in a handful of familiar laboratory organisms like mice. Cancer and ageing are no exception.

But what if we have been looking in too narrow a place?

Every species alive today is the product of millions of years of evolution. Over that time, different species have evolved remarkable ways of responding to disease, environmental change, and other challenges faced by humans. My research explores what these evolutionary innovations can teach us about human and animal health while also revealing the extraordinary value of biodiversity.

The common thread running through my work is comparison.

Rather than asking how humans work in isolation, I ask why species differ. Evolution has generated an incredible diversity of biological solutions to seemingly intractable problems. By comparing species, we can begin to understand why some are remarkably resistant to disease while others are unusually vulnerable. Those differences are more than curiosities of nature; they are clues to how biology works.

One question that has fascinated me is how cancer varies across the tree of life.

Together with evolutionary biologist Dr Ylenia Chiari, my collaborator and wife, I have turned to reptiles, a group that includes some of the longest-lived animals on Earth. Most cancer research has understandably focused on humans and other mammals, making reptiles a largely unexplored source of biological insight.

How often do reptiles develop cancer?

Our first question was simple: how often do reptiles develop cancer? By bringing together pathology records from zoos around the world, we found that turtles and tortoises rarely develop cancer, with rates far lower than those reported for humans and other mammals. We are now beginning to uncover why. Early evidence suggests that their cells may be particularly effective at eliminating damaged cells before they become problematic and may also be unusually resilient to certain forms of DNA damage, such as from UV light.

Our latest research takes us to the opposite extreme. Rather than studying a species that rarely develops cancer, we investigated one in which cancer is unfortunately common. The lemon frost leopard gecko was bred by reptile enthusiasts for its beautiful pale colouration. Yet the same genetic change that gives these geckos their striking appearance also causes most (80%) of individuals to develop highly aggressive skin tumours. It is a remarkable example of how selecting for one desirable trait can have profound and unexpected biological consequences. By comparing tumour and healthy tissue, we found many of the same biological pathways involved in human cancers, suggesting that despite more than 300 million years of evolutionary separation, these geckos develop cancer through surprisingly familiar mechanisms.

What does this mean for human medicine?

The next challenge is to understand how discoveries like these can inform human medicine. Biomedical research rightly relies on well-established model systems, but comparative biology offers something different: the opportunity to uncover biological strategies that evolution has refined over millions of years. By identifying mechanisms that are shared across species, we may discover entirely new approaches to preventing or treating disease. We are now keen to build collaborations with cancer biologists who can help translate these evolutionary discoveries into questions that can be tested in human systems.

Ultimately, this is why biodiversity matters. Every species represents a unique evolutionary solution to life’s challenges. By looking beyond the usual model organisms, we gain new ways of understanding not only the natural world, but also ourselves. Some of the most important ideas in tomorrow’s medicine may come from places we have only just begun to explore.