Genetics of Domesticated Behavior in Dogs and Foxes - Genetics and the Behavior of Domestic Animals - page 382

The farm-fox experiment showed that modification of a specific behavior
(friendly response to humans) can affect other aspects of behavior as well.
Tame foxes are eager to establish human contact from a very early age ( Trut,
1999 ), develop close attachment to their owners when raised in human homes
(Trut, personal communication), and are as skillful as dog puppies in using
human point-and-gaze gestures for finding the hidden food ( Hare et al., 2005;
Hare and Tomasello, 2005 ). Behavioral testing of kits from two farm-bred
populations (i.e. the unselected population and the population selected for
tame behavior), using the object-choice test, demonstrated that although fox
communicative skills had not been used as a selection criterion ( Trut et al.,
2009 ), the tame foxes were as skillful in reading proximal point cues as
age-matched puppies of domestic dogs and outperformed foxes from the unse-
lected population. These results suggest that reduced fear and/or aggression to
humans may be a prerequisite for the development of advanced inter-specific
communicative skills in canids and the ability and wiliness of tame foxes
to read human cues has appeared as a by-product of, or is associated with, the
selection for tame behavior ( Hare et al., 2005 ). Thus, the fox experiment
provides an independent line of evidence for the argument that reducing fear
and aggression can support the development of interactive behaviors.
Play activity of tame foxes persists into adulthood and they actively
seek communication with humans and other foxes ( Belyaev et al., 1985;
Kukekova and Trut, 2010; Plyusnina et al., 1991 ). Many other differences of
behavior between tame and aggressive foxes that are not directly related to
their response to humans remain to be investigated.
Selection of foxes for positive responses to humans led rapidly to the devel-
opment of a behavioral repertoire with significant parallels to that of domestic
dogs. The prehistoric domestication of the dog from the wolf may have taken a
longer time and more generations but in all probability was similarly achieved
through selection for behavioral modifications. The similarities between the
behaviors of domesticated foxes and dogs suggest that the behavioral response
to humans in these two species could involve similar sets of genes.
SUMMARY
Archeological and molecular data have well documented the long history of
coexistence of humans and dogs. Although the full scenario of historical dog
domestication remains to be determined, the behavioral differences between
dogs and wolves strongly argue that selection for behavior was the force that
created “Man's best friend”. The fox domestication experiment demonstrated
that many behavioral characteristics that differentiate dogs from wolves can
be obtained by selection solely for a friendly response to humans. The rapid
progress in selection of foxes for tame behavior strongly suggests that selec-
tion was acting on genetic variation pre-existing in the founder fox population.
These results support dog domestication hypotheses that suggest that pre-dog