dc.description.abstract | Domestic dogs, Canis lupus
(variety familiaris), show extremes
of morphological variation in
comparison to their ancestor, the
wolf (Canis lupus), with some breeds
being much smaller than a typical
wolf (males 40-60 kg, females 30-
45kg), while other breeds are much
larger. A major trend observed to be a
result of the process of domestication
is paedomorphosis, or retention
of juvenile traits into adulthood.
Dogs express paedomorphic traits
to different degrees, ranging from
phenotypes that resemble wolves
to extreme forms such as toy dogs,
with short muzzles and legs. These
traits can be both morphological
to behavioral in nature. Such traits
must interact because morphology
is used to express behavior. One
key example of this is the use
of both ear and tail orientation
to signal status in interactions
among dogs. By observing dyadic
encounters, I measured the extent
of paedomorphic reduction of the
ability to use signaling behaviors,
specifically those involving the ears
and tails. I did not find a correlation
between overall paedomorphosis
and frequency of signaling, but
did find significant interactions
between signal frequency and the
degree of dissimilarity of the tail of
individual breeds from a wolf tail.
Despite this interaction, I found that
signaling was consistent across breed
types and sizes. This indicates that
signaling is highly conserved and
evolutionarily important, even across a large range of phenotypes. When
tail signaling is reduced, it is often
associated with a highly variant tail,
especially those artificially shortened
by human action. | |