There is evidence dogs and humans have co-existed for 12,000 years and that possibly ancient humans and dogs now extinct may have formed symbiotic relations up to 30,000 years ago. As i sit here writing this I look not far away at that beautiful Kelpie I call 'Rosie' look at me with both the contentment of a well exercised,well fed companion and an eager eye, just in case I may do something, move somewhere or just maybe ask something of her.
The current population of Humans is nudging 7billion and the world dog population somewhere near 300 million, it is without question that neither of our numbers would be so high or so widespread without our relationship. It was our ability to leave behind excess food near our camps that brought the hound in from the cold too lie beside our fires and curl up next to us during cool nights.
It is this ability to keep man warm at night that has helped us reach morning on so many a night during the ice ages that allowed humans to push boundaries of their hunting ranges and it is a over eagerness to provide food that lead to many other animals wanting to join in on the growing human camps that may have lead to a less kind relationship such as that with rats, mice, lions, wolves and snakes. It was dogs who alerted us to those animals that would sneak up and hurt us, it was dogs that kept us safe from snakes and rats and all of these jobs desired an inclination in humans assist that development of dogs to selectively breed and amplify traits which would best suit what task would lead to more food and therefore more offspring for both humans and hounds.
My little Kelpie laying patiently on her mat holds all the information to our long shared history, she is an expert herder, a manipulation on her desire to hunt, she is an expert tracker, an intensification of her senses, a loyal companion and extension of her social instinct and yet an expert killer of rodents.
Dogs have made our journey into the unknown much easier they have been trained to pull carts and allow humans to travel vast distances across Siberia and the Americas, hunt food in new lands that evade man, warm the new breed of human who's role doesn't include physical exertion like monarchs and monks and yet allow for better organisation of the whole populations. Dogs too provide a food source that few other animals can especially on ocean going craft where there is no ready source of sustenance for herbivores during a time when the only way to have a steady supply of protein is to keep animals with you. Melanesians, Micronesians, Asians and Polynesians would never have been able to cover the expanses of the pacific without dogs as both assistants in find food on their newly discovered islands and as a ready food source en-route. Just as the later Europeans found dogs to be essential for the long haul travel as bed warmers, companions, scouts when on strange lands and as Captain James Cook needed a high protein food source during times of iron deficiency.
When man first chose to explore beyond the planet it was a dog he trusted to go first into space just as he did when he explored new lands here on earth, after all the irony can not be lost on the fact that it was on a boat named for a trusted explorer the 'Beagle' that took Charles Darwin on his epic journey of understanding of how we as living creatures are all joined.
Dogs to have assisted humans in our need for hygiene, it is they who have consumed human waste both from the living and the dead, it is dogs that convert our waste and our corpses into energy that we can use in our symbiotic cycle. It was dogs who cleaned the battlefields of mans wars amongst themselves to control resources and they still do in many parts of Africa and Central Asia, for the western armies they still provide their service searching out for land mines and lost comrades.