Alan Turing earned deserved fame in computing and cryptography, but he didn’t confine himself to one subject. One of his famous papers dealt with biology, and has just been spotted written all over the eyes of insects.
In 1952 Alan Turing published a paper titled, “The Chemical Basis of Morphogenesis.” Morphogenesis is the process by which an animal develops from an embryo into its adult shape. Turing argued that small instabilities can lead to huge differences in pattern and shape. In the paper, he writes, “It is suggested that a group of chemical substances, called morphogens, reacting together and diffusing through a tissue, is adequate to account for the main phenomena of morphogenesis. Such a system, although it may originally be quite homogeneous, may later develop a pattern or structure due to an instability of the homogeneous equilibrium, which is triggered off by random disturbances.”
Two or more chemical substances can start off in the same place in a developing organism. A few little random changes will cause them to react with each other in different ways, and form wildly different patterns over time. Turing sketched out a model to show how this could happen—now called the Reaction-Diffusion Model.
This year researchers at the Lomonosov Moscow State University took a microscope and examined the patterns of antireflective coating on the eyes of insects, hoping to use the patterns in the coating to classify them. Working from a preliminary evolutionary tree, they took a look at insects and found... absolutely no correlation between the structures on their eyes and their place on the tree.
The patterns were definitely there. There were four main states, and a variety of identifiable transitions between them. The only problem was those patterns couldn’t be fit to an evolutionary model. The patterns could only be fit into the patterns predicted by the Reaction-Diffusion Model. Alan Turing’s 1952 idea had been proven, thanks to the eyes of insects all over the world.
The fact that the patterns don’t give us information about the evolution of the insects doesn’t mean the information is useless. Researchers are hoping that knowledge of the patterns, along with more data gathered by studying fruit flies, can give them an understanding of the proteins making these patterns, which they can then use to make antireflective coatings for industrial use.
Top Image: Mikhail Kryuchkov Second Image: Artem Blagodatsky et al