Genetics of Domesticated Behavior in Dogs and Foxes - Genetics and the Behavior of Domestic Animals - page 359

indigenous to North America, establish the origin of New World dogs as
from Old World wolves ( Leonard et al., 2002; Vil` et al., 1999; vonHoldt
et al., 2010 ). Village dogs from Africa that did not experience the population
bottleneck associated with modern breed formation, and the Australian dingo
and New Guinea singing dogs, were also sourced to ancient dogs domesti-
cated in Eurasia ( Ardalan et al., 2012; Boyko et al., 2009; Larson et al.,
2012 ; Oskarsson et al., 2011; Savolainen et al., 2004 ). The multiple recent
studies of dog ancestry differ in their estimate of how many domestication
events led to the emergence of modern dog lines ( Larson et al., 2012;
Savolainen et al., 2002; Vil` et al., 1997 ), and further document recent
admixture events between dogs and wolves ( Andersone et al., 2002;
Anderson et al., 2009; Vil ` et al., 1997, 2003; Vil ` and Wayne, 1999;
vonHoldt et al., 2010; Wayne and vonHoldt, 2012 ). For example, shared
genomic regions between some European breeds and European wolves indi-
cate admixture events between the two species after the divergence of dogs
from wolves in the course of dog domestication ( vonHoldt et al., 2010;
Wayne and vonHoldt, 2012 ).
Despite the differences in detail cited above, it is clear that dog domesti-
cation occurred at a time when modern Homo sapiens were hunter-gatherers,
and soon after the first entry of modern humans into geographical regions
populated by the wolf ( Clutton-Brock, 1995 ). A long co-existence of dogs
with humans is supported by recent findings of genomic signatures in the
genome of the dog, but not the wolf, associated with the adaptation to a
starch-rich diet ( Axelsson et al., 2013 ). Although just how humans and pre-
dog wolves benefitted mutually from their new-found coexistence is still an
open question, several scenarios have been proposed ( Coppinger and
Coppinger, 2001; Lorenz, 1954 ). Significant modification of the dog domes-
tication picture came with recognition of the genetic basis of differences in
the social behavior of dogs and wolves ( Acland and Ostrander 2003;
Coppinger and Coppinger, 2001; vonHoldt et al., 2010 ). The current hypoth-
esis proposes that dog domestication was a genetic selection for specific
behaviors in the course of a long-term co-existence of pre-dog wolves with
humans ( Acland and Ostrander, 2003; Coopinger and Coopinger, 2001; Hare
et al., 2002; Miklosi et al., 2003 ). Formation of this genetics-centered view
of dog domestication was influenced in large part by the farm-fox domestica-
tion experiment ( Trut 1999, 2001; Trut et al., 2009 ) which is reviewed in
this chapter.
The importance of dogs to human society is reflected in ancient art
( Olsen, 1985; Zeuner, 1963 ) and by ancient co-burial of humans with dogs
( Davis and Valla, 1978 ). Wall paintings of dogs in ancient Egypt show that
distinct types of dogs had already existed 2500

4500 ybp ( Zeuner, 1963 ).
The morphotypic range of such ancient dogs remain with us today among
modern breeds such as mastiffs, hounds, and toy breeds,

indicating that

distinctly different dog types first appeared thousands of years ago