Why were humans able to dominate the world around us? It was all because of our ability to use collective learning but more than that, we were able to domesticate wolves into dogs which have helped us as we have moved through time by helping with herding, which some dogs still do, or they could be doing things as simple and aiding the blind. There are many different things that these wonderful animals can do.
As time went on, people domesticated dogs further and further. As time went on and people continued to breed dogs, they increased collective learning because they were able to breed different types of dogs together to create new breeds. Further than that, as they bred dogs, they were increasing collective learning because they were using selective breeding to create the new breeds of dogs.
As time went on, when humans were still nomadic, there were wolves that were stressed-out and starving and were being pushed out of their territories by humans. On the other hand, the smarted and more tame wolves had smarter and more tame wolf pups that people were able to domesticate into man's best friend, the dog.
Although dogs are all descended from a common ancestor, the reason that there are so many different breeds and types of dogs is because of years and years of selective breeding. As time went on, people got more and more picky about what they wanted in their dogs so they would use selective breeding in order to get these traits.
Dogs as a whole had many different uses which were beneficial to us. Some of the uses were to haul supplies, be guards, they even had religious significance to some people. The most negative use in my mind, is that there were cases where dogs were used as a food supply. If people had to haul things long distances, they would use dogs if they had nothing else to use. They would be guards if needed. Depending on the religion, dogs would stand as a symbol for a religion. They were used as food if food supplies were cut short and people had to help feed their families.
Dogs were domesticated from the common ancestor, the wolf, and they have become, what we know as, "man's best friend", the dog. Over time dogs have changed so much, such as beagles getting longer ears, or other dogs standing taller. As time has gone on, and will continue going on, dogs have changed and they will continue to change as we get more picky with selective breeding.
The thresholds that dogs would fall into are 3,5, and 6. It fits into 3, "New Chemical Elements", because at the big bang, all the elements that will be created were created right then but as time went on people found more and more and they have figured that these chemicals are in our body and animal's bodies. It fits into 5, "Life On Earth", because that's when life on Earth began to evolve and eventually became the gray wolf and eventually were domesticated into the dog. It fits into 6, "Collective Learning", because it was trial and error when it came to domesticating dogs and it took help from people to increase our collective learning to be able to domesticate the loving dog.