Every time a cell divides, there is a chance for a mutation (mistake) to occur in the DNA – the substance that carries genetic information in all living organisms. These mutations can lead to cancer.
If all cells have a similar chance of developing cancer-causing mutations, then very large and long-lived animals with more cells undergoing more cell divisions should develop cancer at a higher rate than smaller, short-lived animals with fewer cells dividing over less time.
But in 1977, Sir Richard Peto noted thathumans develop cancer at a rate similar to mice. This is despite having 1,000 times as many cells and living 30 times as long. Another example of this phenomenon can be found in elephants. They…
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