Spots and stripes can be found everywhere in the animal kingdom.
From the savannahs of Africa to the coastal waters off southern Australia, countless species boast distinctive markings.
For decades, scientists have been trying to work out how these animals develop their unique patterns.
Now, they may have just figured it out.
Building on work by previous researchers – including mathematician Alan Turing – a team have proposed a ‘simple idea’ that can explain how cells assemble to create patterns.
‘Imperfections are everywhere in nature,’ they wrote in the journal Matter.
‘Our work bridges the gap between idealised models and the messy beauty of real systems.’
Using their model, they were able to simulate the development of patterns that look strikingly similar to what appears in nature – finally cracking the code behind how markings form.
Experts looked at natural patterns in fish – such as the hexagonal markings on ornate boxfish – and tried to recreate them for their study
The team said imperfections are ‘everywhere’ in nature – adding that spots and stripes are rarely uniform (file image)
Building on work by previous researchers – including mathematician Alan Turing – a team have proposed a ‘simple idea’ that can explain how cells assemble to create patterns such as the stripes that zebras are famous for (file image)
The team started with a theory, first proposed by Turing, which suggests as skin tissue develops it produces chemicals that diffuse into the system – similar to pouring milk into coffee.
Some of these chemicals activate pigment–producing cells, forming spots or stripes, while other chemicals inhibit these cells, creating the blank spaces in–between.
Computer simulations using this theory, however, produced spots that were blurrier than those found in the natural world.
Next, they added another layer to the theory – that cells use a mechanism called diffusiophoresis to ‘pull’ other particles along with them.
Attempts to recreate the hexagon patterns found on ornate boxfish showed this extra ‘rule’ created results that were too perfect – all hexagons were the same size and shape and the space between them were identical.
The final piece of the puzzle, they found, lies in the fact that developing cells are different sizes, meaning they produce imperfect patterns and textures when they move.
Their final simulations showed breaks and grainy textures that looked far more like what’s found in nature.
‘We are able to replicate natural patterns with striking similarity,’ they wrote.
The team reveal how pigment cells begin scrambled together (as pictured) before separating to form distinct patterns
Here, the diffusiophoresis process can be seen underway as the cells move and ‘pull’ other particles with them
The final result is a pattern that looks ‘strikingly’ similar to those that appear in nature, they concluded
Lead researcher Ankur Gupta, from the University of Colorado at Boulder, said humans have always drawn inspiration from nature.
Understanding how pattern–making cells assemble could help engineers design materials than can change colour based on the environment, much like a chameleon’s skin.
It could also help design effective approaches to deliver medicine to a specific part of the body.
‘We are drawing inspiration from the imperfect beauty of natural system and hope to harness these imperfections for new kinds of functionality in the future,’ he said.
