For dog owners, it is sometimes hard to imagine how the docile dachshund seated on your lap is actually a descendant of a wolf.

It is even harder to understand how all dogs, despite their common ancestry, come in different shapes and sizes; with some small enough to fit into a handbag and others big enough to easily topple you over.

Ever since the first modern human appeared some 200,000 years ago, dogs have been constantly hanging about human settlements.

They do not just act as lapdogs, but also perform a variety of tasks including sledding, hunting and herding.

In an interesting twist, dogs who are now among our closest friends are direct descendants of one of our ancestors’ fiercest natural enemies, the grey wolf.

When humans first arrived in Eurasia about 100,000 years ago, the wolf proved to be a powerful and capable threat.

Its physical capabilities were to be feared, with powerful jaws and an even more powerful sense of smell.

As though they were not intimidating enough, wolves, like humans, lived and hunted in packs and would cooperate when hunting down prey.

They were persistent hunters, who knew that even if they could not catch their prey, they could outlast it until it fell due to exhaustion.

The arrival of humans changed their playing field, with wolves correctly regarding the newcomer bipeds as dangerous rivals.

However, while most wolves regarded humans as a threat, a select few, particularly ones without a pack, realised there was opportunity to be found with the primates.

They did not immediately turn into lapdogs; instead they stayed on the outskirts of settlements feeding on scraps and leftovers.

As the populations of docile wolves reproduced, genes were passed on and tamer wolves came into being in human-populated areas.

Eventually, humans began to use these docile wolves for a myriad purposes, including hunting and guard duties.

Their pack structure made it easier for these animals to find a place in human families and learn to understand their commands.

Over time, they stopped hanging around the outskirts of villages to finally start living in human houses, becoming the first animal domesticated by humans.

The first of these Proto-Dogs or Wolf Dogs, which appeared about 33,000 years ago, would have physically resembled their wild cousins.

Where they differed though was their smaller size and a shorter snout equipped with relatively smaller teeth.

These Proto-Dogs would grow diverse and specialised alongside human society.

Short stocky dogs, akin to today’s corgi, were livestock herders which nipped at heels; elongated dogs, such as today’s dachshund, forced badgers and foxes out of burrows.

Thin and sleek dogs, like greyhounds, chased prey around; and large muscular dogs, of the Rottweiler type, guarded properties.

These different types of dogs began to be classified as separate breeds during the Victorian era, and many new dogs came into being due to people wanting the cutest dog possible.

However, some of these cute dogs gained their looks at a cost to their health, and some breeds can be said to be healthier than others.

Some dogs for example have difficulty breathing while others have spinal problems.

There are also other side effects from humanity’s longest experiment in controlled evolution, namely dogs are now more tied to human beings than our ancestors could have ever anticipated.

Canines are one of the few animals who can understand human emotion and body language; with interaction releasing oxytocin in both dogs and humans, a love hormone associated with empathy and social bonding.

It might be difficult to imagine how dogs, ranging from the tiny Chihuahua to the massive Tibetan mastiff, have ancestors in ferocious wolves.

But think about it this way. The many diverse breeds are the result of an ancient relationship that has lasted through countless cataclysms and even the extinction of our Neanderthal cousins.

Perhaps, you should consider it heart warming that given enough time, even the most dangerous of our enemies can become our most loyal of friends.

As Roy Blount Jr once wrote, “A dog will look at you as if to say, ‘What do you want me to do for you? I’ll do anything for you.’ Whether a dog can in fact, do anything for you…is another matter. The dog is willing.”