Complex patterns in frustrated synchronization

Although best known for his roles in founding the field of computer science and in cracking the German Enigma cipher, Alan Turing also made a profound impact on developmental biology. In a 1952 paper, he proposed that a system of chemical substances that react together and diffuse through a tissue could account for morphogenesis—the differentiation of identical cells to form patterns and structures, such as our off-center hearts, zebra stripes, and the formation of fingers and toes. In 2014 Seth Fraden and colleagues at Brandeis University experimentally tested Turing’s model in rings of coupled microdroplets undergoing the famous oscillating Belousov–Zhabotinsky chemical reaction. Brandeis’s Bulbul Chakraborty and her colleagues have now traced the roots of the observed complex spatiotemporal patterns. The theorists worked with a well-studied oscillating reaction model that incorporates an activator and an inhibitor, and they applied it to “cells” arranged in a ring. They found that in the...