Over thousands of years, the dog has been carefully bred for a variety of behaviors, senses, and physical characteristics. Dog breeds differ greatly in terms of size, color, and shape. They serve humans in a variety of capacities, including hunting, herding, hauling loads, protection, support for law enforcement and the armed forces, therapy, and assistance to the disabled. Domesticated Scientific classification Edit this classification Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Family: Canidae Genus: Canis Specie
Classification
The domestic dog may have descended from the grey wolf, according to a 1999 study on mitochondrial DNA (mitochondrial DNA), with the development of the dingo and New Guinea singing dog varieties occurring during a period when human settlements were more isolated from one another.
The process of domestication
A typical example of a domestic animal that most likely followed a similar path to domestication is the dog. For many years, geneticists and archaeologists have struggled to answer the problems of when and where dogs were initially domesticated. Genetic research indicates that domestication of one or more wolf populations in Europe, the high Arctic, or eastern Asia may have started more than 25,000 years ago.
Types of Animals
Dogs are the most diverse mammal on the planet, with over 450 recognized breeds globally. Directed human selection produced a wide variety of phenotypes in the Victorian era, giving rise to the present dog breeds. Within the previous 200 years, a small handful of founders produced the majority of breeds. Since then, people have artificially selected for dogs, causing them to go through rapid phenotypic change. There is more phenotypic variation in the dimensions of the skull, body, and legs within breeds than there is in the entire order of predators.
Layer
The outer skins of domestic dogs are categorized as “double” or “single” depending on whether they have a topcoat solely or a mix of coarse guard hair and soft down hair. “Double” coats are common across dogs and wolves from colder climes. Breeds occasionally have a white fur “flame,” “perform,” or stripe on their breast or bottom. Dogs may start to exhibit premature graying beginning as early as one year of age; this is linked to impulsive, anxious behaviors as well as dread of strange noises, people, or animals.
Health
Dogs can become poisoned by a number of human foods and household items, such as chocolate, which can cause theobromine poisoning, onions and garlic, which can cause thiosulfate, sulfoxide, or disulfide ingestion, raisins and grapes, macadamia nuts, and xylitol. Tobacco includes nicotine, which can be harmful to dogs as well. Diarrhea or excessive vomit (from ingesting cigar butts, for example) are indications of poisoning. Hydrocarbon combination indigestion can cause vomiting, mouth ulcers, aspiration pneumonia, stomach pain, and even death.