Dmitry Belyaev's Foxes

A problem people have with the evolutionary pathway from wolves to dogs is that they don't know how breeding for tameness can produce all the variation found in dogs. It is understood that today people breed dogs for their looks. They want the right angle of the ears and the perfect coat, but 1000s of years ago when wolves were beginning the domestication process, those were not what was being selected for but those different looks and styles did inevitably show up. But how?

In Siberia, the Russian geneticist, Dmitry Belyaev, has been breeding less ferocious animals, particularly foxes. He used a process that we have heard about many times before. He would only breed the tamest from every litter. What he wasn't expecting to see though was that after only 10 generations he started to see foxes with ears turning downward, tails turning upward, different coats, and some were even barking. The same changes that occurred in wolves 1000s and 1000s of years ago was happening in his own lab and to foxes! Belyaev knew that he couldn't have been selecting for these genes in his breeding because those genes weren't there to be selected for to begin with!

So what Belyaev then decided to do was test all his foxes for different hormone levels. What he found out was that they all had significantly lower levels of adrenaline. This makes sense because these foxes were the tamest of the tame from 10 generations. The biochemical pathway that affects adrenaline levels is the same biochemical pathway that deals with melanin which shows up and a affects the foxes coat. This goes to show that breeding for tameness helps produce different levels of hormones which leads to a cascade of changes.

Breeding for tameness destabilizes the genetic makeup of the foxes, and by proxy, wolves which is a major factor in how we go the great diversity we have in dogs!