African Elephants Develop Genetic Defenses Against Cancer
Research reveals a groundbreaking association between body size and cancer prevalence among various species. A comprehensive analysis covering 263 species indicates that larger animals, traditionally thought to have higher cancer risks due to having more cells, have evolved mechanisms to mitigate this risk.
“This study provides empirical evidence showing a correlation between body size and cancer rates, highlighting that larger species tend to experience more cancer than their smaller counterparts,” states a researcher from University College London.
Contrary to past studies that found no significant links between body mass and cancer, this research draws from a much broader dataset, examining 79 bird species, 90 mammals, 63 reptiles, and 31 amphibians. The data was compiled from autopsy records documenting cancer occurrences in captive animals.
Findings show that larger species were more likely to have cancer at the time of death. Specifically, for every 1 percent increase in the body mass of birds and mammals, there was a corresponding 0.1 percent increase in cancer rates. For reptiles and amphibians, increases in body length correlated with a 0.003 percent increase in cancer rates.
This research challenges the longstanding concept known as Peto’s paradox, which suggests that cancer rates should correlate with body size. However, experts note that the correlation observed is notably minor and not proportional to body size disparities.
Further, the research indicates that larger species may have evolved enhanced mechanisms for cancer defense. By analyzing evolutionary trends, the team discovered that bird and mammal species with rapid increases in size tended to have better cancer defenses.
Previous investigations have identified genetic adaptations in elephants and whales that bolster cellular defense mechanisms and promote DNA repair, consequently reducing cancer risk. Understanding the biological pathways in these cancer-resistant animals could pave the way for novel cancer therapies in humans. This could lead to the development of targeted drugs designed to exploit these evolved mechanisms, potentially offering more effective cancer treatments.
