The Golden Ratio (Phi, or φ = 1.618. . .) is a unifying quantity of structure and function in nature as it underlies morphogenesis in living organisms as well as in many other naturally occurring phenomena. The ratio can be observed by taking a line and dividing it into two unequal parts, with the length of the longer part divided by the shorter length being equal to the entire length divided by the longer part. This will always yield the Golden Ratio, and structures that obey this partitioning are ordered based on the Phi proportion.
The unification of quantity of structure with function in the Phi ratio is most evident by its reoccurrence in human anatomy and physiology. Now in a new comprehensive study performed at John Hopkins, researchers have found that the human skull dimensions follow the Golden Ratio, and what is most remarkable is that in other related mammalian species the skull morphologies diverge from Phi.
The Johns Hopkins researchers compared the neocranium of 100 human skulls to 70 skulls from six other animals and found that the human skull dimensions converged on the Phi ratio—while the skulls of less related species such as dogs, two kinds of monkeys, rabbits, lions and tigers diverged from this ratio. Such results indicate that the difference between the ratios show a trend toward convergence on φ correlating with species complexity.
The anatomy and evolution of the human skull have been the focus of intense study. Evolving over millenia, the human skull embodies an elegant harmonization of structure and function. –Rafael Tamargo and Jonathan Pindrik, MDs at John Hopkins, 2019.
RSF in perspective
Rafael J. Tamargo, Jonathan A. Pindrik. Mammalian Skull Dimensions and the Golden Ratio (Φ). Journal of Craniofacial Surgery, 2019; 30 (6): 1750 DOI: 10.1097/SCS.0000000000005610