A 1952 mathematical theory proposed by World War II codebreaker Alan Turing has been proven to explain the complex, overlapping patterns of shark scales
A system proposed by World War II codebreaker Alan Turing more than 60 years ago can explain the patterning of tooth-like scales possessed by sharks, according to new research.
Scientists from the University of Sheffield’s Department of Animal and Plant Sciences found that Turing’s reaction-diffusion theory — widely accepted as the patterning method in mouse hair and chicken feathers — also applies to shark scales.
The findings can explain how the pattern of shark scales has evolved to reduce drag whilst swimming, thereby saving energy during movement. Scientists believe studying the patterning could help to design new shark-inspired materials to improve energy and transport efficiency.
Alan Turing developed the brilliant reaction-diffusion system in 1952, just two years before his tragic death.
Prior to this he was famously involved in the cracking of the Enigma code used by the Germans during the Second World War.
His equations describe how molecular signals can interact to form complex patterns in a variety of different systems.In the paper, published in the journal Science Advances, researchers compared the patterning of shark scales to that of chicken feathers.
Dr Gareth Fraser, now at the University of Florida, said: ‘We started looking at chicks and how they develop their feathers.’We found these very nice lines of gene expression that pattern where these spots appear that eventually grow into feathers.
‘We thought maybe the shark does a similar thing, and we found two rows on the dorsal surface, which start the whole process.’
They found that the same core genes involved with feather patterning also underpin the development of shark scales.
Mr Cooper added: ‘Scientists and engineers have been trying to create shark-skin inspired materials to reduce drag and increase efficiency during locomotion, of both people and vehicles, for many years.
‘Our findings help us to understand how shark scales are patterned, which is essential for enabling their function in drag reduction.’Therefore, this research helps us to understand how these drag-reducing properties first arose in sharks, and how they change between different species.’He said patterning is an important aspect that contributes to achieving drag reduction in certain shark species. Another is the shape of individual scales.
The researchers now want to examine the developmental processes which underlie the variation of shape both within and between different shark species.
Mr Cooper added: ‘Understanding how both these factors contribute towards drag reduction will hopefully lead towards the production of improved, widely applicable shark-inspired materials capable of reducing drag and saving energy.’
