Un-Natural Selection for FAIL... and WIN

Understanding mutation is basic to understanding evolution and dogs.

The concentration of mutation is what "selective breeding" is all about, but in the case of dog breeders it is UN-natural selection rather than natural selection.

Dog breeders are generally selecting for FAIL -- the thing that is rare in nature because it is maladaptive in natural dogs (i.e. it causes them to die or fail to thrive).

The good news for dogs (as well as horses, chickens, cows and other domesticated breeds) is that most mutations are very minor -- an odd coat color, an odd-shaped head, a particular behavior trait -- which are not fatal in the sheltering wake of free food and shelter provided by humans.

Return the dog, chicken, horse, or cow to the wild, however, and devolution quickly occurs as unsuccessful mutations are culled out in the absence of human protection and food subsidy.

Of course one of the mutations that has made dogs different from wolves is a small mutation in temperament -- brains capable of more trust and less aggression. 

If we look around the world today, we find primitive and not-so-primitive people routinely bringing wild-caught baby animals into their huts and tents -- monkeys, parrots, tapirs, pigs, cheetahs, hawks, fox, badger, and coyote.  

Some wild animals, if caught young enough and trained the right way, settle into an uneasy life of captive bondage, but most do not.  Wolves are a species that teeters on the cusp.  Out of 1,000 wolves caught as pups, perhaps one is calm enough that, if trained in a primitive manner, it can survive into adulthood as a kind of semi-feral camp wolf living among primitive people without chain leash or iron cage. 

Without vaccines or medicine, of course, life for this tame wolf will be short, and finding a mate with a similarly relaxed outlook on life is not too likely. 

In all probability, it was only after scores of thousands of years that a small line of "tame wolves" was created and became large enough, and useful enough, to be a self-sustaining feature among some primitive camp people. 

This was the first dog.

The genes that control fear and aggression are not single-function bits of code.  Like all genes, they control quite a few other things as well.  In this instance they appear to control morphology -- coat color, ear shape, facial shape, and tail carriage, as we see in the Russian Fox experiment, below.




And so we are on our way. With new expressions of coat color, ear shape, and tail carriage we now start breeding for external appearance.

Over time, the natural scenting and prey drives of dogs are also harnessed and refined to chase rabbits, point bird, scent badger, and chase deer. While some dogs are bred for a kind of phlegmatic biddability (think retrievers and lap spaniels), others are bred for a little more rev in the engine (think working terriers and butcher's dogs).

Over all this time, the human population of the world is growing. It took two million years for the population of the world to hit one billion (1830) but only 100 years to add the next billion (1930). By 1960, just 30 years later, we had added our third billion. Subsequent billion-mark human population thresholds were crossed in 1975 (4 billion), 1987 (5 billion) and 1999 (6 billion). The world's population will click past 7 billion this year.

As a consequence of human population growth, the world has less space for wolves. Humans have roaded, channeled, plowed, fenced, logged, and restocked the world with those domesticated versions of wildlife that it finds useful. The wolf is from another time. It is wild and untamed. It is not useful and so, like a weed in a corn field, it is cut out even as its domesticated version -- the dog -- is brought in to sit next to us by the fire. Un-natural selection for FAIL in the natural world of the past has proven to be selection for WIN in the tamed, roaded and track-homed world of today.
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