Posted on 16 September 2020
Longevity briefs provides a short summary of a novel research, medicine, or technology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.
Why is this research important: Looking within one specie, the increased body size of a member correlates with increased cancer risks. Interestingly, that’s not the case if we look between the species. Whales have much lower incidents of cancer than humans, despite much larger bodies. It is also known as Peto’s paradox in biology. Therefore it is crucial to understand underlying anti-cancer mechanisms in large animals for potential medical applications.
What did the researchers do: Researches at the University of Chicago have studied the clade of mammals called Afrotheria. Members of this clade vary significantly in size (African bush elephant and golden mole both belong to this monophyletic group, meaning they have a common ancestor), which makes them great for research on Peto’s paradox. Researches have analyzed the evolution of their body mass, cancer risks and gene copy number variation.
Key takeaway(s) from this research: Despite the initial hypothesis that only large members of Afrotheria clade (such as elephants and mastodons) will have enriched cancer protection (duplication of tumour suppressing genes), researches have discovered that development of said protection has occurred at various points throughout the evolution of Afrotheria, regardless of the body size. This suggests that duplication of tumour suppressor genes may have contributed to the evolution of larger bodies and reduced cancer, but does not mean that those processes were coincident.