Peto’s Paradox

Here is a puzzle from biology with a lesson for everything: large animals have thousands of times more cells than small ones, each cell a chance for cancer — yet whales and elephants get less cancer, not more. More risk, multiplied vastly, somehow equals less harm.

The resolution: scale changes the game. Whales evolved extra layers of defence — more tumour-suppressing machinery, better repair — because at their size, cancer defence was worth the investment. The problem, grown large enough, funded its own solution.

The general principle travels far: some problems cannot be solved at small scale but can at large. The village cannot afford a fire brigade; the city can. The single patient cannot fund research; ten thousand patients can. A difficulty multiplied is sometimes a difficulty that finally has a budget.

So when a problem seems overwhelming precisely because it is big, ask the whale's question: what defence becomes affordable at this scale? Size is not only an amplifier of trouble. Sometimes it is the thing that makes the solution possible — the paradox being that the biggest creatures are proof.