Dogs have been bred for many different characteristics:
- physical attributes
- coat color, height, weight, muscle mass, etc.
- intelligence (Dog intelligence ratings)
- instinctual behaviors
- herding, tracking, retrieving, guarding, etc.
For thousands of years, dogs have been used by people in many roles. Over several hundred years, people have deliberately selected dogs with different characteristics to do different jobs.
Dogs have been bred for many different characteristics:
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Purebred dogs are true breeding lines, just like the pea varieties Mendel used to study inheritance.
So, just as Mendel used crosses between different types of peas to study inheritance of pea pod color and shape, scientists today can use crosses between different breeds of dogs to study the inheritance of physical attributes, intelligence and behaviors.
The Dog Genome Project is studying the inheritance of approximately 31 traits or characters. This is a collaborative project between scientists at the University of California at Berkley, the University of Oregon, and the Fred Hutchinson Cancer Research Center in Seattle, Washington.
The Dog Genome Project crossed a Newfoundland with a border collie. These two breeds exhibit many different behaviors. These two breeds are also descendant from the two most divergent groups of domesticated dogs.
Newfoundland mother "Pepper" |
Border Collie father "Gregor" |
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| easygoing, affectionate, water loving, loyal, extra large (~150 lbs), all black coat | brainy, intense, workaholic, medium size (~35 lbs), black coat with white markings |
Trait/behavior |
Newfoundland |
Border Collie |
|---|---|---|
| size | extra large |
medium |
| coat color | all black |
black with white markings |
| showing eye | absent |
strong |
| crouch | absent |
strong |
| eye contact with owner | absent |
strong |
| biddability | absent |
strong |
| tail posture when running | held high |
held low |
| barking at home | moderate |
very low |
| running gait | bounding |
sprint |
| scent vs sight | scent |
sight |
| sensitivity to noise | insensitive |
sensitive |
| water preference | high |
low |
| people in water | attentive/intervening |
indifferent |
| affection demands | high |
low |
| sociability with other dogs | high |
low |
There have been two litters (these represent F1 generations).
Altogether there were seven puppies. All the puppies grew up to look similar to one another, they were smaller than their mother and bigger than their father. There were mostly all black like their mother. All of them "showed eye" and displayed a crouch like their father, and were water loving like their mother.
There are 23 F2 individuals. Each dog was distinct from other F2 individuals. All of the F2 dogs were bigger or smaller than their F1 parents. There were more white markings on the F2s than on their F1 parents.
There were unique combinations of behaviors: one F2 showed eye, loved people and was indifferent to water, a second F2 carried his tail like a border collie, did not show eye, loved people but did not swim.
The behaviors seen in individual F2s suggest that many genes control this behavior. Individual F2 dogs have different combinations of the components of the herding behavior. Selection of herding ability in early dogs by prehistoric peoples was probably a complex process.
Yes, DNA analyses are being conducted on all of the generations in this study: parents, F1 and F2 generations. Those DNA markers which are only found in dogs that "show eye" are likely to be near the gene(s) for this behavior, similarly those DNA markers only found in dogs that have white markings are likely to be near the gene(s) for white coat color. For more information about how to map genes read these online publications:
For more information go to What is the Dog Genome Project? or read Smithsonian Nov. 1996 pp. 126-137.
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Please send comments and suggestions to: moconnel@nmsu.edu
Last Updated: July 10, 1998
