In “On Growth and Form,” D’Arcy Wentworth Thompson argued that organisms are shaped less by adaptive evolutionary function and more by deep mathematical laws. To understand his argument, you need only look at the combs made by beesby Philip Ball / June 29, 2017 / Leave a comment
A book published 100 years ago by a Scottish zoologist named D’Arcy Wentworth Thompson is one of the most remarkable scientific works of the 20th century. Called On Growth and Form, it was and remains sui generis. A blend of natural history, mathematics, physics and engineering, it offered a very different take on life from the Darwinian viewpoint favoured by Thompson’s contemporaries. Instead of explaining all shape and form in biological organisms by an appeal to its adaptive evolutionary function (torpedo shapes are optimal for fish swimming though water and so on), On Growth and Form asserted that living forms are best understood as diagrams of the forces that act on them.
As Thompson put it: “Cell and tissue, shell and bone, leaf and flower, are so many portions of matter, and it is in obedience to the laws of physics that their particles have been moved, moulded and conformed.”
This quote tells you something else about On Growth and Form: it is a jewel of scientific writing. The eminent British biologist Peter Medawar called it “beyond comparison the finest work of literature in all the annals of science that have been recorded in the English tongue.” The polymathic Thompson was also a distinguished classicist (during his studies at Cambridge University he supported himself by teaching Greek), and it shows.
It’s not easy to sum up what you’ll find in On Growth and Form, except to say that it is as full of wonders as a Renaissance cabinet of curiosities. Here is maths applied to the spiraling arrangement of seeds in a sunflower head, which turns out to be related to a series of numbers called the Fibonacci series known at least since the thirteenth century. There you find dinosaur skeletons analysed according to the same engineering principles used to plan the Forth Bridge near Thompson’s home city of Edinburgh. Here are more spirals: the so-called logarithmic spiral that defines the shapes of animal horns and snail shells, which encodes the allegedly “perfect” proportions called the Golden Mean. There, jellyfish shapes are compared to splashes in milk, and the trellis-like bony “exoskeletons” of microscopic sea creatures are explained using the geometric theories of polyhedra written down by Euclid.