Ever wonder how dogs evolved?
From Pekingese to St. Bernard and greyhound, dogs come in such startling variety it's easy to forget they belong to the same species. The profusion of breeds today -- at least 150 -- reflects intense, purposeful interbreeding of dogs in the past 150 years.
At the same time, the entire history of dogs and their
relationship with humans has undergone some rethinking recently, thanks in
large part to high-tech molecular dating methods that can determine
evolutionary relationships and chronologies.
The dog, Canis familiaris, is a direct descendent of the gray wolf, Canis lupus: In other words, dogs as we know them are domesticated wolves. Not only their behavior changed; domestic dogs are different in form from wolves, mainly smaller and with shorter muzzles and smaller teeth.
How and when this domestication happened has been a matter
of speculation. It was thought until very recently that dogs were wild until
about 12,000 years ago. But DNA analysis published in 1997 suggests a date of
about 130,000 years ago for the transformation of wolves to dogs. This means
that wolves began to adapt to human society long before humans settled down and
began practicing agriculture.
The dog, Canis familiaris, is a direct descendent of the gray wolf, Canis lupus: In other words, dogs as we know them are domesticated wolves. Not only their behavior changed; domestic dogs are different in form from wolves, mainly smaller and with shorter muzzles and smaller teeth.
Darwin was wrong about dogs. He thought their remarkable
diversity must reflect interbreeding with several types of wild dogs. But the
DNA findings say differently. All modern dogs are descendants of wolves, though
this domestication may have happened twice, producing groups of dogs descended
from two unique common ancestors.
How and when this domestication happened has been a matter
of speculation. It was thought until very recently that dogs were wild until
about 12,000 years ago. But DNA analysis published in 1997 suggests a date of
about 130,000 years ago for the transformation of wolves to dogs. This means
that wolves began to adapt to human society long before humans settled down and
began practicing agriculture.
This earlier timing casts doubt on the long-held myth that
humans domesticated dogs to serve as guards or companions to assist them.
Rather, say some experts, dogs may have exploited a niche they discovered in
early human society and got humans to take them in out of the cold.
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