Differences in the Behavior of Landraces and Breeds of Dogs - Genetics and the Behavior of Domestic Animals - page 222

or to control for developmental events, and in essence to understand the
synergistic (interactive) effects of environment on developmental processes
( Serpell and Jagoe, 1995 ). Indeed the criticism of heritability studies is their
inability to test genetic and environmental

interactions ( Hirsch, 1990;

Wahlsten, 1990 ).
Most working dog breeders solve these problems by breeding the best to
the best, independently of other morphological or behavioral considerations.
Perhaps the lesson for the household dog industry is that until we understand
behavior genetics it would be advisable to breed the best companion dogs
together irrespective of other considerations.

“Now suppose there were a being who did not judge by mere external appearances,
but who could study the whole internal organization, who was never capricious ... ”
Darwin, 1858

DISCUSSION
Dog and dog breed behavioral and genetic divergence has been illustrated
with five types of dogs. For each type we hypothesized mechanism(s) of
behavioral divergence.
First, we postulate that the domestic dog that we know today is an adap-
tation to permanent human settlement. The existence of the niche is evident
from the number of species that are “exclusively” associated with permanent
human settlement. That background population of village scavengers has a
long and unbroken history and is still growing as the human population
grows ( Coppinger and Coppinger, 2001 ). This hypothesis differs consider-
ably from the popular, widely held view of many, many authors, that diver-
gence was the result of people consciously removing animals from the wild,
and selectively breeding them to produce domestic phenotypes (for a recent
review of this hypothesis, see Shipman, 2009 ).
Second, the alternative view is that the wild species' self-initiated reduc-
tion of flight distance from humans is what led to domestication. This
reduced flight distance, and interspecific food-begging behaviors, are also
common behavioral traits of rats, pigeons, and other species that are self-
adapted to human settlement. Natural selection for reduced flight distance
could be the result of the behavioral energetics of a scavenger associated
with human settlements. Diagnostic characters of dogs, including coat color
and patterning, ear carriage, and aberrant vocalizations, need not be viewed
as adaptations, but simply as saltations incurred during the processes of rapid
selection for reduction of flight distance. Non-seasonal and diestrous cyling
are thought to be adaptations to a stable food supply of human waste ( Lord
et al., 2013 ).
Third, in both models, domestication precedes taming. Taming is a result
of variation in the developmental environment. Breed divergence and