A regular cheetah (standing) and a king cheetah, showing off its broad back stripes.
CREDIT: Courtesy of the Ann van Dyk Cheetah Preserve

This week’s just-so story is, “How the kitty got its stripes.”  All the news are on it; they just don’t answer the question.

News media are not the least embarrassed to invoke the Kipling just-so story formula, “how the got its y.”  In this week’s iteration about cat stripes, Live Science headlined, “How the tabby got its stripes.”  Science Daily was a little more creative (or verbose) with, “How the Sub-Saharan Cheetah Got Its Stripes: Californian Feral Cats Help Unlock Biological Secret.”  Even the prestigious journal Science’s news site got into the act with, “How the Tabby Got Its Blotches.”

What the original paper in Science found were genes in tabby cats that, when mutated, form blotches rather than stripes.  Then the research team checked mutant cheetahs with blotches and found the same mutation.  That’s about all.  The paper is by Kaelin et al., in Science, “Specifying and Sustaining Pigmentation Patterns in Domestic and Wild Cats” (21 September 2012: Vol. 337 no. 6101 pp. 1536–1541, DOI: 10.1126/science.1220893).  The most detailed summary was on Science Daily, echoing a Stanford press release, “How the Cheetah Got Its Stripes: A Genetic Tale by Stanford Researchers” (there they go again).

“We were motivated by a basic question,” said Barsh of the turn to the study of big (and little) cats. “How do periodic patterns like stripes and spots in mammals arise? What generates them? How are they maintained? What is their biological and evolutionary significance?  It’s kind of surprising how little is known. Until now, there’s been no obvious biological explanation for cheetah spots or the stripes on tigers, zebras or even the ordinary house cat.”

That’s about all that was said by anyone about evolution: only questions.  None of the scientists or authors explained how these genes “emerged” in the first place.  None of them explained how genes, inside of cells, create precision patterns on the external fur of multicellular mammals.  The press release said that many animals, such as fish and insects, have patterns, but they grow them differently: they add more stripes as the animal grows, whereas your kitten’s pattern will remain the same as it grows to adulthood….

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