Class blog for sharing and commenting on current events in biology.

Monday, September 24, 2012

How to Build A Dog

Matt Drygulski              September 24, 2012
Core Biology I Honors/C-block Ms. Davies

Ratliff, Robert. “How To Build a Dog” National Geographic Online. Feb2012.

Dogs are the most diverse animals on the planet. Dog shows, such as the Westminster Kennel Club Dog Show, is the perfect opportunity to display the great variety of canine breeds in one place. The array of different shapes, sizes, and colors is almost endless. From the great size and strong legs of a Doberman, to the small size and stubby legs of a dachshund. But how did dogs become so diverse?
According to scientists, evolution of wolves into dogs started almost 20,000 years ago. The first semi-domesticated wolves were mixed by humans to create a new type of wolf that is built for specific tasks, creating the modern dog. Of course, it took many, many generations to achieve even the smallest change. At first, dog-wolves were bred for hunting, guarding, and companionship. Thousands of years later, the process somehow jump-started to create the specific dog for a specific purpose by mixing and matching breeds. In only a last couple hundred years, breeders created 350-400 new breeds of dogs. For example, to create a dog for the purpose of cornering badgers, some kind of hound was combined with a terrier to create a new variation of a dog with stubby legs and a rounded body that allowed it to chase the badger into its burrow. This dog is known today as the dachshund.
This human interference with dog evolution changed the genes of canine anatomy. Scientists believed that this diversity led to genetic diversity. However, surprisingly there are only a few genes that control a dogs shape, color, and size.   
According to recent studies, there are certain genetic codes that can change a dachshund to a Doberman. It was discovered that the variety amongst dogs is decided by only a small amount of specific genes. Slight variations and switches of 50 genes cause the size, color, hair length, shape, fur type, nose shape, and ear positioning of a dog.
          However, this variation is something specific to dogs, as being the most diverse animals. Normally a trait or disease is caused by a combination of many genes, but in dogs, it is caused by only a handful of them. This discovery can be very important, as it helps us to understand genetic disorders shared between humans and dogs. Scientists can see what genes cause these disorders in dogs and then look for it in humans, as dogs have much simpler genetic codes than us.  
            I chose this article because I love dogs and I was always very interested in learning about them. I also find the study of genetics very interesting. The more I read, the more fascinated I was. Anyone who has a dog would be surprised to see that their Chihuahua is the same as a Great Dane, except with some simple genetic switches. The article also has relevance to the human world as scientists are using these canine genetics to understand disorders shared between humans and dogs. This discovery in dogs can revolutionize the study of genetic disorders in humans.
            The article is very informative. An outside connection is made, examples are given, and a bit of history is shown. I am impressed by the information and how it relates to humans. The article, however, needs some kind of background on genetics for someone who does not fully understand the notations of genetics and how genes work. This could be more valuable in the understanding of the main idea of the article. Overall, however, the article conveys its meaning and displays a very interesting discovery in the world of genetics.  

1 comment:

  1. I think that the article you chose was both very interesting as well as being very informative. The areas that you really shined in though was mainly in how you presented this vast amount of information without making it extremely boring and dull. The second being how your organized the information into a very easy and understandable format that isn't very hard to follow. The third and final area being the choice of the article. The article you chose was extremely interesting in my opinion because I had no idea that the evolution of dogs started 20,000 years ago. I was very impressed on how informative this article was and how in depth it went into each aspect of how dogs became what they are today. Something else I learned was that there are over 400 dog breeds. This really surprised me because I would have never thought an animal could evolve into so many different forms. The only area I believe that you could improve in would be the length of your summary. I personally found it to be a bit to long in some areas but other than that it is perfect. -Spencer Cox