在线英语听力室_免费在线英语听力学习网站

You can’t judge a book by its cover. But you can judge a dog by its coat. You can even read right through to its genes². Because a study in the August 27th online issue of Science shows that just three key genes govern the length and texture³ of dog fur.

Domestic dogs come in a stunning⁴ variety of shapes and sizes, and different breeds wear different coats. They can have short hair or long hair, or fur that’s straight, wavy⁵, curly, wiry or smooth. To find the genes responsible for this furry⁶ rainbow, scientists scanned the DNA⁷ of a thousand individual dogs from 80 different breeds. And they found that every coat’s appearance boils down to three simple traits: length, curl and texture. And that each of these traits is controlled by just one gene¹.

So, a long-haired Golden retriever has one variant⁸ of a gene called FGF5, whereas a short-haired lab has another. By mixing and matching variants⁹ of these three genes, you get everything from a curly-haired poodle to a wire-haired Scottie with bushy eyebrows¹⁰ and a droopy moustache.

Which is probably more than you’ll ever need to know about the hair of the dog that bit you.

—Karen Hopkin