We'd known for a while that if you bring up wolf cubs in a domesticated setting, you get an animal that looks and acts something like a dog but is much more dangerous. You lose thousands of years of selective breeding for domesticated behavior when you bring in the wild wolf genes.
Still true, but it apparently doesn't have to take thousands of years to go a good bit of the way from scratch. Thirty to thirty-five generations did the job in the silver fox case. They even look a lot different.
This clearly indicates that a determined and disciplined breeding program (or, presumably, a suddenly harsh and demanding environment), affecting a small portion of a species, can make a huge difference in just 30 or 35 generations, requiring a period of only 40 years. It's a great demonstration of why, when speciation occurs (as seems to have been underway here), it would be unlikely for there to be a lot of fossils of intermediates. It happens too quickly. In geological terms, you'd have a brand new species in the blink of an eye. And the old species from which they descended would still be around, if they were unaffected by the selection pressures to which the small group were subjected. One geological monent there's one species, then -- whammo! -- two species, obviously related, yet different. And no intermediate links to be found. Amazing.
"They have... lost(link)---a big one."
"They're like Napoleon's army in Moscow. They have occupied a lot of territory, and they think they've won the war. And yet they are very exposed in a hostile climate with a population that's very much unfriendly."