Post by Brooke on Feb 14, 2004 20:16:50 GMT -5
Ten dogs that shaped the canine world
By Steve Connor, Science Editor, in Seattle
14 February 2004
From the tiniest Chihuahua to the largest St Bernard, they all claim the wolf as a common ancestor. But the question which has puzzled dog owners for centuries is: how did they grow to be so different?
The answer is at hand. A new look at man's best friend has revealed that the 300 breeds of dog in the world today can all be grouped into one of 10 categories which have all resulted from a form of Darwinian evolution.
Using ancient manuscripts, historical records, pottery fragments, works of art and modern genetics, scientists have been able to assess how the variety of dog breeds came into existence.
They have studied the common physical and emotional traits among dogs to understand how human breeders through the centuries have created such varied individuals of the same species.
Deborah Lynch from the Canine Studies Institute in Aurora, Ohio, said that selective breeding of dogs for specific traits goes back thousands of years and the diversity stems from how the first dogs were domesticated from the wolf.
"There is no question that the wolf is the direct ancestor of the dog. The link is firm but the evolution of the domestic dog into the more than 300 different breeds that are found throughout the world is a patchwork of folk tales, archaeological finds, oral history, written history and mystery," Ms Lynch told the American Association for the Advancement of Science, in Seattle. Dogs were originally bred to help early hunters but with the rise of agriculture people began to produce different breeds with widely varied characteristics to suit specific roles, she said.
Kennel clubs have divided dog breeds into half a dozen categories, chosen as much for aesthetics as for function, but scientists have found these do not reflect the true evolutionary history of the dog over the past 10,000 years.
"As people began to work with animals in herds, dogs were helpful in both herding and guarding flocks during the Neolithic period," she said.
"With agriculture came more opportunities for dogs to be useful in guarding homesteads and in war. By the Bronze Age, dogs were differentiated into distinct breeds," she added.
Hounds, for instance, can be divided into those that can hunt mainly by sight, such as the greyhound, and those that hunt by scent, such as the bloodhound.
Each of these "progenitor breeds" has a distinct history, with the sight hounds being bred in open desert countries, such as those in the Middle East, and the scent hounds bred in regions such as Europe, where woodland made it difficult to see game.
"Each group of breeds has developed special physical and behavioural characteristics that lend themselves to accomplishing certain tasks. Progenitor breeds can be identified from which several breeds are descended," Ms Lynch said.
Greyhounds are depicted hunting gazelle in ancient Mesopotamia on pottery fragments dating to 5,000BC and they were clearly bred for the purpose of desert hunting. "Gone was the long hair and double coat of the wolf, unsuitable for a warm desert," Ms Lynch said.
"The body had a deep chest, long limbs and a sleek head with a long jaw. It was similar to that of the animals which it hunted - a predator that could catch swift prey," she said.
Other groupings include working and guard dogs, such as the mastiff and rottweiler, that were bred to be aggressive and capable of defending property and livestock or even to act as dogs of war in battles.
Toy dogs were bred early in history as children's pets, with the most likely progenitor breed being the Maltese. Dogs bred for cold, northerly climates probably began with the Norwegian elkhound, while spaniels were bred for flushing out game on land and water.
Pointers were bred for their speed and endurance in hunting upland game, whereas terriers were bred for hunting vermin down holes.
The 10th category is the herding dog, which probably stemmed from a breed that looked like the Canaan dog of Israel.
By Steve Connor, Science Editor, in Seattle
14 February 2004
From the tiniest Chihuahua to the largest St Bernard, they all claim the wolf as a common ancestor. But the question which has puzzled dog owners for centuries is: how did they grow to be so different?
The answer is at hand. A new look at man's best friend has revealed that the 300 breeds of dog in the world today can all be grouped into one of 10 categories which have all resulted from a form of Darwinian evolution.
Using ancient manuscripts, historical records, pottery fragments, works of art and modern genetics, scientists have been able to assess how the variety of dog breeds came into existence.
They have studied the common physical and emotional traits among dogs to understand how human breeders through the centuries have created such varied individuals of the same species.
Deborah Lynch from the Canine Studies Institute in Aurora, Ohio, said that selective breeding of dogs for specific traits goes back thousands of years and the diversity stems from how the first dogs were domesticated from the wolf.
"There is no question that the wolf is the direct ancestor of the dog. The link is firm but the evolution of the domestic dog into the more than 300 different breeds that are found throughout the world is a patchwork of folk tales, archaeological finds, oral history, written history and mystery," Ms Lynch told the American Association for the Advancement of Science, in Seattle. Dogs were originally bred to help early hunters but with the rise of agriculture people began to produce different breeds with widely varied characteristics to suit specific roles, she said.
Kennel clubs have divided dog breeds into half a dozen categories, chosen as much for aesthetics as for function, but scientists have found these do not reflect the true evolutionary history of the dog over the past 10,000 years.
"As people began to work with animals in herds, dogs were helpful in both herding and guarding flocks during the Neolithic period," she said.
"With agriculture came more opportunities for dogs to be useful in guarding homesteads and in war. By the Bronze Age, dogs were differentiated into distinct breeds," she added.
Hounds, for instance, can be divided into those that can hunt mainly by sight, such as the greyhound, and those that hunt by scent, such as the bloodhound.
Each of these "progenitor breeds" has a distinct history, with the sight hounds being bred in open desert countries, such as those in the Middle East, and the scent hounds bred in regions such as Europe, where woodland made it difficult to see game.
"Each group of breeds has developed special physical and behavioural characteristics that lend themselves to accomplishing certain tasks. Progenitor breeds can be identified from which several breeds are descended," Ms Lynch said.
Greyhounds are depicted hunting gazelle in ancient Mesopotamia on pottery fragments dating to 5,000BC and they were clearly bred for the purpose of desert hunting. "Gone was the long hair and double coat of the wolf, unsuitable for a warm desert," Ms Lynch said.
"The body had a deep chest, long limbs and a sleek head with a long jaw. It was similar to that of the animals which it hunted - a predator that could catch swift prey," she said.
Other groupings include working and guard dogs, such as the mastiff and rottweiler, that were bred to be aggressive and capable of defending property and livestock or even to act as dogs of war in battles.
Toy dogs were bred early in history as children's pets, with the most likely progenitor breed being the Maltese. Dogs bred for cold, northerly climates probably began with the Norwegian elkhound, while spaniels were bred for flushing out game on land and water.
Pointers were bred for their speed and endurance in hunting upland game, whereas terriers were bred for hunting vermin down holes.
The 10th category is the herding dog, which probably stemmed from a breed that looked like the Canaan dog of Israel.