Biology Reference
In-Depth Information
symbiotic behaviors with humans are results of developmental proximity.
The crucial ingredients for breed divergence are not genetic but rather are
found in the recipe for manipulating the developmental environment
(e.g., Black and Green, 1985 ). Taming can be defined in terms of the quality,
frequency, and sequencing of interspecifically directed social motor patterns.
The quality of tamed behaviors will be different in the village scavenger
than in the wild type, given similar developmental environments ( Fentress,
1967; Klinghammer and Goodman, 1987; Zimen, 1987 ).
Fourth, specialized breeds are developed by hybridization of size, shape,
and behavior, chosen from a background of existing dogs. A new breed is
the result of choosing from animals that already perform the behavior.
Performing animals are bred together, which might perfect the form in a
manner similar to natural selection. Superficial characteristics, i.e. breed
markers, are the result of sorting between puppies rather than selection for
the character in the Darwinian sense.
Working breeds are divided into two groups: those that are the result of a
specific developmental environment (pastoralist), and those that have a spe-
cialized phenotype (including behavior). The latter breeds of dogs are highly
refined specialists for specific tasks. In the Darwinian sense they are more
complex, more specialized than the ancestor. They outperform the ancestor
for the specific task. They are not degenerated forms, as is often claimed
(see Price, 1984 , for a review).
Fifth, each of the five types of dogs and their ancestors are not geneti-
cally discrete. Individuals can, and do, genetically invade any of the catego-
ries, both locally and temporally. Boitani et al. (1995) and Gottelli et al.
(1994) write about the consequences of hybridization with wolves. Wild
types and village dogs are niche-adapted, and although in a sense humans
provide the environment for village dog evolution, their symbiotic relation-
ship is commensal and not mutualistic. It is neither conscious human behav-
ior nor mutual benefit that leads to domestication (see Rindos, 1980 , for a
counter-argument). We believe that the obligatory commensal behavior of
village dogs is ancestral to that of the various working dogs which are mutu-
alistic with humans. In some cases, this is simply the result of the specific
developmental environment, as with the livestock guardians, while other
cases involve genetic selection for breed-specific motor patterns, as in the
herding and gun dogs. Modern western companion animals are often capri-
cious exaggerations of the working and hunting breeds that are dependent on
human care. It is difficult to measure the benefit of conferring that care,
although many authors try. Consideration of an obligatory parasitism should
be discussed for understanding the welfare of humans, and breeding capri-
ciousness should be analyzed in terms of the dogs' welfare. The clich ´ s like
“man's best friend” seem hypocritical, given the advent of debilitating struc-
tural anomalies which shorten life spans and lead to the inability to perform
any movement without causing pain.
Search WWH ::




Custom Search