Tuesday 9/15 Reading Question

I would counter Darwin's argument by using his example of the various pigeon breeds being selectively bred to establish certain traits not shown in the Rock Pigeon. Why he could see this with one species, but not another is interesting.

Darwin's argument for the domestication of dogs and his rationale for the domestication of pigeons is different, but in my opinion shouldn't be. He argues that such different varieties of pigeon are surely to come from the rock pigeon, but argues that dogs couldn't have come from a single common ancestor. My understanding of species tells me that a species must be able to breed and produce viable offspring. With domesticated dogs (even with the mechanical issues between large and small dogs) artificial insemination would produce a viable offspring. The other problem I have with Darwin's assertion that dogs were bred from a few aboriginal species is there are no aboriginal species running around with similar traits as the greyhound or bull-dog. Where did they go? Of course genetic testing and genome studies are methods to confirm these ideas.

Crossing dogs that have traits that are desired to a breeder would result in offspring that may show these traits...but it would take many generations to isolate and propagate these traits. The Labradoodle is a fine example because of the gentle nature of the Lab (c'mon...ever seen a mean lab?) and the desired trait of an allergy free coat from the Poodle...and it didn't take long for the breeders to get the desired set of traits. According to a Labradoodle website (http://labradoodle-dogs.net/labradoodle-history/) the breed wasn't stared until 1988.

Dawkins looks at what Darwin couldn't. His idea of a "stable" group is one that can carry on based on stability. The domesticated dog has been around long enough for humans to name them. The genetics behind stability is the basis of speciation based on artificially selected traits (by humans) or by the environment. Evolution itself doesn't have an end goal, but artificial selection does. Anyone who has lived with a bull-dog knows that the respiratory problems associated with that breed (in the wild) wouldn't be "stable". The environment selects for stable groups that survive what "she" throws at them, not what traits are desired by "her". Darwin was on the right track, I just don't know why he got the pigeon thing right, and the dog thing wrong.

Ecology could have played a role in the domestication of the dog because of the interaction between a few species. There are very complex social interactions between wolves in a pack environment. The less aggressive wolf may not have survived in a pack situation and may have even been driven from the pack to fend for itself. The proliferation of hunter-gatherer human clans may have been a substitute for the more "tame" wolf, and followed or even been "adopted" by a clan. Both organisms may have benefited from the company of the other (food for the wolf... an "early warning system" for the humans...companionship for both)...but artificial selection would have been the next step. As we discussed in class, the humans would need to remove the more aggressive offspring and kept only those pups that demonstrated the desired trait. Inbreeding and other genetic variation may have played a role, as well as finding other docile individuals until the dog and wolf failed to reproduce based on behavior, not only genetics.

Much like Darwin working on an idea at the same time as Wallace, I'm sure that clans all over were also beginning the process of domesticating dogs, as well as other animals.