Peto's paradox is the observation that larger and longer-lived animal species do not have proportionally higher cancer rates despite having more cells and more time to accumulate cancer-causing mutations.
November 24, 2025
high
conceptual
A general principle in cancer biology explaining why body size and lifespan do not directly predict cancer incidence across species.
A 2025 study found that bowhead whales (Balaena mysticetus) produce abundant amounts of a DNA-repair protein that enhances repair of broken DNA, helping maintain cellular integrity and reducing accumulation of mutations associated with cancer.
November 24, 2025
high
biological
Comparative genomics and molecular studies of long-lived species can reveal mechanisms of enhanced DNA maintenance that may inform cancer biology.
Elephants (genus Loxodonta) have approximately 20 copies of the tumor suppressor gene TP53 (p53) while humans (Homo sapiens) have a single copy; the p53 protein can trigger cell death (apoptosis), initiate DNA repair, and inhibit cell division to limit propagation of pre-cancerous cells.
November 24, 2025
high
genetic
Copy number expansion of tumor suppressor genes is one documented evolutionary strategy in large, long-lived animals to reduce cancer risk.