At my high school reunion, I was thrilled to see a few four legged attendees. This Peke-Chin Mix is one of a pair of great bookends that showed up with a former classmate.
via Australian
The evolutionary secret of how the dachshund got its short legs has been uncovered. Dachshunds, corgis, basset hounds and Pekingese are among the common breeds that owe their short legs to the mutation of a single gene that occurred several thousand years ago. The discovery offers insight into the way genetic mutations drive evolution and may have implications for understanding dwarfism in humans.
A team from the American National Human Genome Research Institute, in Maryland, examined DNA samples from 835 dogs from 76 breeds, including 95 animals with short legs. The scientists found that dogs from all the short-legged breeds had an extra copy of a gene that produces a growth protein called FGF4, which is known to be implicated in dwarfism in humans. The extra gene is a mutant of a type known as a retrogene, which lacks parts of the normal DNA code.
The extra retrogene leads to an overproduction of the FGF4 protein, which appears to alter the times at which bones grow in embryonic development. This, the scientists believe, causes the legs of small dogs to remain short and out of proportion to their bodies. The findings are published in the journal Science. As the same gene is shared between all the short-legged breeds of dog studied, the mutation is likely to have emerged early in the evolution of dogs.
Fossil evidence suggests dogs were first domesticated from wolves at least 14,000 years ago, and genetic evidence suggests the evolutionary split may have happened earlier than that. Eric Green, scientific director of the National Human Genome Research Institute, said the research shows how genetic information can help us to understand the course of evolution.
Predatory Drift is a sudden, and drastic change in a dog's demeanor that is characterized by behaviors associated with hunting small prey.
The term is most often used to describe a medium to large dog who has suddenly and uncharacteristically targeted a smaller dog as prey (dinner).
Predatory Drift is NOT Aggression, but it can mean injury or death for small dogs.
Predatory Drift happens when the larger dog's instinct to hunt are triggered.
These instincts can be triggered when play escalates or gets too much like the real thing (an out of control chase game). It can happen when a small dog gets scared or injured and squeals or wriggles in a way that makes them look like prey (dinner), Predatory Drift can happen just because thesize difference says, "You are comparatively bite-sized, or move like something that is bite-sized, and I am a canine predator."
The most alarming fact about Predatory Drift is that it can happen even with well-behaved, well-socialized, playful dogs who play well and often with no aggression, and no fights.
Dogs who are triggered into predatory drift, may or may not have ever been in a dog fight, and may or may not be generally well-behaved and obedient. There is NO protection against predatory drift. It is not a good dog/bad dog problem.
Predatory Drift is not about how brave, strong, feisty, or fearless the small dog acts. Predatory Drift is not about how well your medium or large, or extra large dog plays, listens to you, or how many times they have met, played with or been around a small dog.
Predatory Drift can even happen between two dogs that know each other well and have lived, played, and or known each other for years. In the right situation, a sudden shift happens and the predatory sequence (like dominoes falling) is triggered and completed with lightening fast speed.
While it is not a problem seen every day, all it takes is the slightest trigger -an injury, a fight, a response to something startling or scary. Predatory Drift is a SIZE MATTER! It usually involves a grab and shake, which instantly breaks the small dog's neck. There is no time to react. This in not a fight, it does not escalate. There is a trigger and then it is over.
Read more...
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