How did the tiger get its stripes? Scientists in England say they've figured out the biological mechanisms behind the big cat's trademark look - and it's a bit more complicated than one of Kipling's Just So Stories.
According to researchers at King's College London, their findings, published in the journal Nature Genetics, confirm a theory put forth in the 1950s by mathematician and code-breaker Alan Turing, the man considered the father of the computer.
Turing theorized that a pair of morphogens, substances that govern how cells develop into tissues, work together as an "activator" and "inhibitor" causing regular repeating patterns in biological systems.
According to the Telegraph, "One of the chemicals, [Turing] suggested, triggered cell activity, while the other hindered it. The way in which they interact would dictate where cells grow, creating familiar patterns on the fur of animals."
To test this theory, the researchers tested a spot on another animal that shows such patterns - the evenly spaced ridges in the mouths of mice.
According to a post by King's College London:
Carrying out experiments in mouse embryos, the team identified the pair of morphogens working together to influence where each ridge will be formed. These chemicals controlled each other's expression, activating and inhibiting production and therefore controlling the generation of the ridge pattern...They showed that when these morphogens' activity is increased or decreased, the pattern of the ridges in the mouth palate are affected in ways predicted by Turing's equations.
Dr. Jeremy Green from the Department of Craniofacial Development at King's Dental Institute says that this is the "first experimental identification of an activator-inhibitor system at work in the generation of stripes" and better understanding of this process could, in future, be used "to regenerate structure and pattern when differentiating stem cells into other tissues."
Green also notes that, fittingly, this confirmation comes during Turing's centenary: he would have turned 100 this June.