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Sable (dog)
The coat of the domestic dog refers to the hair that covers its body. Dogs demonstrate a wide range of coat colors, patterns, textures, and lengths. As with other mammals, a dog's fur has many uses, including thermoregulation and protection from cuts or scratches; furthermore, a dog's coat plays an important role in the showing of purebred dogs. Breed standards often include a detailed description of the nature and attributes of that breed's ideal coat. A dog's coat is composed of two layers: a top coat of stiff guard hairs that help repel water and shield from dirt, and an undercoat of soft down hairs, to serve as insulation. Dogs with both under coat and top coat are said to have a ''double coat''. Dogs with a ''single coat'' have a coat composed solely of guard hairs, with little or no downy undercoat. The terms fur and hair are often used interchangeably when describing a dog's coat, however in general, a double coat, like that of the Newfoundland and most livestock guar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dog Coat Variation
The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Dogs were the first species to be domesticated by hunter-gatherers over 15,000 years ago before the development of agriculture. Due to their long association with humans, dogs have expanded to a large number of domestic individuals and gained the ability to thrive on a starch-rich diet that would be inadequate for other canids. The dog has been selectively bred over millennia for various behaviors, sensory capabilities, and physical attributes. Dog breeds vary widely in shape, size, and color. They perform many roles for humans, such as hunting, herding, pulling loads, protection, assisting police and the military, companionship, therapy, and aiding disabled people. Over the millennia, dogs became uniquely adapted to human behavior, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ghost Population
A ghost population is a population that has been inferred through using statistical techniques. Population studies In 2004, it was proposed that maximum likelihood or Bayesian approaches that estimate the migration rates and population sizes using coalescent theory can use datasets which contain a population that has no data. This is referred to as a "ghost population". The manipulation allows exploration in the effects of missing populations on the estimation of population sizes and migration rates between two specific populations. The biases of the inferred population parameters depend on the magnitude of the migration rate from the unknown populations. The technique for deriving ghost populations attracted criticism because ghost populations were the result of statistical models, along with their limitations. Population genetics In 2012, DNA analysis and statistical techniques were used to infer that a now-extinct human population in northern Eurasia had interbred with both th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
