Scientists from the University of Sheffield’s Department of Animal and Plant Sciences found that Alan Turing’s reaction-diffusion theory can unlock the secrets for the growth patterns of shark scales.
The findings help explain how a shark’s skins has uniquely evolved to minimize drag while swimming. Scientists believe these pattern may help to design new synthetic materials to improve energy and transport efficiency.
Turing’s theory, which describes how molecular signals can interact to form complex patterns, has previously been applied to growth patterns of mouse hair and chicken feathers.
“We teamed up with a mathematician to figure out what the pattern is and whether we can model it. We found that shark skin denticles are precisely patterned through a set of equations that Alan Turing—the mathematician, computer scientist and the code breaker—came up with,” University of Sheffield researcher Dr. Gareth Fraser said. “These equations describe how certain chemicals interact during animal development and we found that these equations explain the patterning of these units.”
The paper, which was published in the journal Science Advances, compared the scale growth patterns of shark scale with chicken feathers. The study found that the same core genes that determines feather patterning also igoverns the development of shark scales.
“We found these very nice lines of gene expression that pattern where these spots appear that eventually grow into feathers,” Fraser said. “We thought maybe the shark does a similar thing, and we found two rows on the dorsal surface, which start the whole process.”
The study also suggests that natural variations to Turing’s system may have enabled the evolution of different traits within these animals, including the provision of drag reduction and defensive armor.
“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,” Sheffield Ph.D student Rory Cooper said. “Our findings help us to understand how shark scales are patterned, which is essential for enabling their function in drag reduction.