On Being the Right Size

It’s hard to deny the clear and convincing arguments made in the 1928 paper On Being the Right Size by the excentric geneticist  J.B.S. Haldane. According to Haldane every living thing grows into the size it’s supposed to have. Eyes, Lungs, wings and limbs all listen to simple laws of nature, most of which have something to do with gravity and the relationship between surface and volume of the body. The most important functions are all related to getting enough oxygen and energy to the cells, keeping enough heat in to stay warm, and creating enough support to keep it all going.

Many of the things we are investigating in relation to The Incredible Shrinking Man need to be considered in the light of this important essay. Haldane illustrates that if our eyes were to shrink we probably wouldn’t be able to see as much, and to stay warm we may have to eat quite a lot more then the 60 calories we predicted for a person of 50 centimeters.

Beyond certain limits it gets hugely complicated and even damaging to grow taller. People suffering from gigantism already move with great difficulty but real giants would break their legs with every step they’d take.  The smaller body may also become simpler as we won’t have to twist and turn our intestines and lungs to create enough surface area to support our nutritional and oxygen needs. Haldane: ‘The higher animals are not larger than the lower because they are more complicated. They are more complicated because they are larger. … Comparative anatomy is largely the story of the struggle to increase surface in proportion to volume.’ But that’s only needed if you intend to become larger, and we don’t.