Page 9 - The Complete Dog Breed Book Choose the Perfect Dog for You, New Edition (DK)

WHA T IS A DOG ? 9

THE SHAPE OF A PREDATOR Even with the use of genetic
The canid family are shaped to be analysis, unraveling the history of a
efficient hunters. This Weimaraner particular breed is not easy. Some
remains true to his ancestral body plan
and can move with speed and grace. breeds are commonly said to be very
ancient, but genetic evidence
that wolves were more trusting of suggests that the majority are, in
humans and could learn and adapt fact, modern recreations. With few
to human behavior, and so in part exceptions, most breeds known
may have domesticated themselves. today were developed no earlier
Over subsequent generations, this than the 19th century.
led to physical developments (such as
drop ears) and behavioral changes (such as increased Dog anatomy
friendliness) to encourage humans to fulfill their needs. The physical characteristics of a dog are typical of a predator
Hundreds of years passed before deliberate breeding whose survival relies on efficiency in locating and catching
became more sophisticated—selecting for coat type, color, prey. Humans have done much to adapt canine design, but
temperament, and specialized skills—eventually creating the basic anatomy of all breeds of dog is the same.
hundreds of different breeds. The selection processes have The skeleton of the dog evolved to provide speed,
altered over the years, and while certain characteristics fall strength, and maneuverability. A highly flexible spine and
out of favor, others become embedded in the breed standard. freely moving forelimbs allow a dog to move with a long,
swinging stride. The most important characteristics of a
Information from dog DNA dog’s skeleton are seen in the legs. The two large forearm
In the past, the history of a dog breed was pieced together bones, the radius and the ulna, are locked together in such
from written records, pictures, and information handed a way that a dog can make rapid changes of direction
down from past breeders and owners. Today, the analysis without the bones rotating and breaking. In a further
of DNA (the hereditary template found in body cells) has adaptation, two of the wrist bones are fused together—unlike
also made it possible to track the inheritance of features the separate bones seen in humans—to give a dog strength
such as size and coat color and to look at the differences and stability when moving in a straight line. Combined with
and similarities between one breed and another. Most long, powerful toes, with claws like spikes on running shoes,
importantly, looking at DNA has made it possible to identify this limb arrangement gives a dog a high degree of control
which breeds are at risk of specific genetic diseases and whether it is running, jumping, or turning.
conditions (see pp.338–339). Scientists sequenced the Classified as carnivores, dogs are anatomically adapted
first complete dog genome (the complete set of genetic to eat primarily meat—although, given the opportunity,
information possessed by an organism) in 2005 using domestic dogs will eat almost anything. A dog’s teeth are
the DNA of a Boxer. designed to deal with tough foods such as hide, flesh, and
PACK MENTALITY
Doing things cooperatively is a built-in canine
characteristic, but domestic dogs now look to humans
rather than other dogs when they need help.

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