#DIFFERENT TYPES OF WILD DOGS SERIES#

They found that at least 155 different regions of the dog's genome show evidence of strong artificial selection. A joint venture between the University of Washington and the Veterinary School at UC Davis mapped the variation in the genomes of a mere 10 different breeds of dogs. And it's not just their skulls that vary. The amazing diversity of dogs is a testimonial to the possibilities of selection. In just a few centuries, our choices have created unbelievable variety in the heads of dogs - more than 60 million years has created in the rest of the carnivores.

Much of this variation is outside the range of the rest of the order, meaning dogs' skull shapes are entirely unique.

What does that mean, exactly? It means that the differences between the skulls of that Pug and Great Dane I mentioned before (on R) are greater than the differences between the skulls of a weasel and a walrus. They found that there was as much variety in the shape of the skulls of dogs as in the entire rest of the order, and the extremes were further apart. A study recently compared the positions of 50 recognizable points on the skulls of dogs and compared them to each other and other members of the order Carnivora. But years of hand-picked puppies has led to an amazing amount of skull diversity in dogs. Like other members of the order Carnivora, dog's skulls have a few distinctive characteristics: relatively large brains and a larger-than-normal structure called a zygomatic arch which allows for bite power and chewing. And in doing so, we spurred on rapid diversification and evolution in an unbelievable way. We picked dogs that were less aggressive or looked unique. We not only allowed these traits to persist, we encouraged them. Still, we opened up a number of genetic traits and allowed them to express variety that would have been fatal in the wild. There were some traits that made this easy - the social structure of wolves, for example, made them predisposed to belonging to a community. But when people pulled specific wolves out of their packs and began breeding them, we changed everything. Before domestication, dog's life was tough. We've turned a fine-tuned hunting animal, the wolf, into a wide variety of creatures, from the wolf-looking shepherds to the bizarre toy breeds. Those that doubt whether small variations in traits can lead to large levels of diversity clearly haven't compared a Pug to a Great Dane - I mean, just look at them compared to their ancestor: While humans have been breeding dogs for over ten thousand years, it was until recently that strict standards and the emphasis on 'purebreds' has led to over 400 different breeds that are some of the best examples of the power of selection. If only Darwin knew what we know now, that indeed, all dogs did descend from one species! it could be shown that the greyhound, bloodhound, terrier, spaniel and bull-dog, which we all know propagate their kind truly, were the offspring of any single species, then such facts would have great weight in making us doubt about the immutability of the many closely allied natural species At the time, he believed that dogs varied so much that they must have been domesticated from multiple canine species. A century and a half ago, Charles Darwin recognized how the incredibly diverse dogs supported his revolutionary theory in his famous book On The Origin Of Species. Man's best friend is much more than a household companion - for centuries, artificial selection in dogs has made them prime examples of the possibilities of evolution.

#DIFFERENT TYPES OF WILD DOGS SERIES#

I'll be reposting the series over the next two months, culminating in a brand new post for the set in Jan 2012! I'm excited.

This is the first in a series of post of mine about Evolution that I started posting in January of 2010.

Different types of wild dogs