Figuring out how cat coloration comes about could help scientists understand our immune system’s resistance to infectious diseases.

On NPR.com, Joe Palca quotes researcher Stephen O’Brien as saying that they’re trying to explain why "some cats are spotted, some cats have stripes, some cats have what we call blotches, and other cats don’t have any of that, they just have a black or a lion-like color." The genetic variants that determine those patterns come from different mutations in the same genes.

Cats with narrow stripes have a working copy of one specific gene, but if a mutation turns that gene off, the cat ends up with a blotchy pattern.
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It’s actually the opposite: A new study demonstrates that our genes are controlled by our culture and environment.

Here’s an example: In the Wall Street Journal, Matt Ridley writes: "All mammals can digest lactose sugars in milk as babies, but the lactase gene switches off at weaning when no longer needed. In much of Europe and parts of Africa, by contrast, most people can digest lactose even as adults, because the lactase gene remains switched on. (About 90% of East Asians and 70% of South Indians are lactose-intolerant to some degree.)
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