Differences in the Behavior of Landraces and Breeds of Dogs - Genetics and the Behavior of Domestic Animals - page 195

preserve the greater aesthetic appeal of the young animal.” The point is that
domestication is an analog to natural selection; it is not the experimental test
of the hypothesis. The argument becomes circular.
There is ample evidence that domestication happened very quickly (per-
haps 9000 years ago), and that landrace forms of domestic breeds appeared as
the result of natural selection. Breeds, however, are not products of natural
selection but the result of founder effects, mutational anomalies, and hybrid-
ization, causing saltations (phylogenetic leaps, or novelties in form, as distinct
from Darwin's gradualism). In other words, there were sudden changes in
both physical characteristics and behavior. In this paper we explore the
processes of breed divergence, especially exploring breed-specific behaviors.
In the last 20 years researchers have attempted to determine the phylo-
genetic origins of dogs and the location of those origins by means of neutral
mutation theory. So far, such techniques cannot account for effects of popu-
lation size or genetic drift ( Coppinger et al., 2010 ) or the effects of frequent
hybridization (admixture) ( Larson et al., 2012 ).
Rindos (1980) described domestication as a developing symbiotic rela-
tionship between humans and the domestic species. Symbiosis is often used
as a synonym for mutualism, defined as two species living together for
mutual benefit. Ecologists, however, reserve the word mutualism for a per-
manent and obligatory relationship that benefits both species. Other forms of
symbiotic relationships are (obligatory) commensalism, where the benefit is
entirely for one species while the other neither benefits nor is harmed, and
(obligatory) parasitism, which benefits the one species to the detriment of
the other. As we discuss the various breeds of dogs, we will explore their
ecology and suggest how their behavior evolved and what kind of symbiotic
relationship they have developed with humans.
FIVE KINDS OF DOGS
Five types of dogs are described, each representing a behavioral “type form”
(a taxonomic standard for comparison) of domestic dogs. Descriptions of
morphological and behavioral uniqueness of each of these types provide a
background for discussion of the genetic bases for their breed-specific
behaviors.
The five types are based on contemporary observations and studies.
There are perhaps 700,000,000 to a billion dogs in the world, with humans
having reproductive control over a minority of them ( Stafford, 2007 ;Lord
et al., in review). Probably 75% or more of the dogs in the world reproduc-
tively behave as any wild species and are subject to natural selection. These
are commonly the landrace dogs, those local types of domestic canids that
evolve mainly on their own by, as it were, natural selection. All over the
world, their adaptation to their immediate environment has resulted in a
huge population of dogs that are usually short-haired, weigh about 14 kg,