A brief history of dogs - David Ian Howe

3,188,639 views ・ 2019-03-26

TED-Ed


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Since their emergence over 200,000 years ago,
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modern humans have established homes and communities all over the planet.
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But they didn’t do it alone.
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Whatever corner of the globe you find homo sapiens in today,
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you’re likely to find another species nearby:
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Canis lupus familiaris.
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Whether they’re herding, hunting, sledding, or slouching
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the sheer variety of domestic dogs is staggering.
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But what makes the story of man’s best friend so surprising
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is that they all evolved from a creature
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often seen as one of our oldest rivals:
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Canis lupus, or the gray wolf.
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When our Paleolithic ancestors first settled Eurasia roughly 100,000 years ago,
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wolves were one of their main rivals at the top of the food chain.
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Able to exert over 300 lbs. of pressure in one bone-crushing bite
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and sniff out prey more than a mile away,
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these formidable predators didn’t have much competition.
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Much like human hunter-gatherers,
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they lived and hunted in complex social groups
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consisting of a few nuclear families,
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and used their social skills to cooperatively take down larger creatures.
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Using these group tactics,
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they operated as effective persistence hunters,
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relying not on outrunning their prey,
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but pursuing it to the point of exhaustion.
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But when pitted against the similar strengths of their invasive new neighbors,
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wolves found themselves at a crossroads.
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For most packs,
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these bourgeoning bipeds represented a serious threat to their territory.
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But for some wolves,
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especially those without a pack,
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human camps offered new opportunities.
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Wolves that showed less aggression towards humans
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could come closer to their encampments,
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feeding on leftovers.
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And as these more docile scavengers outlasted their aggressive brethren,
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their genetic traits were passed on,
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gradually breeding tamer wolves in areas near human populations.
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Over time humans found a multitude of uses for these docile wolves.
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They helped to track and hunt prey,
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and might have served as sentinels to guard camps
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and warn of approaching enemies.
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Their similar social structure made it easy to integrate with human families
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and learn to understand their commands.
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Eventually they moved from the fringes of our communities into our homes,
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becoming humanity’s first domesticated animal.
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The earliest of these Proto-Dogs or Wolf-Dogs,
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seem to have appeared around 33,000 years ago,
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and would not have looked all that different from their wild cousins.
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They were primarily distinguished by their smaller size
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and a shorter snout full of comparatively smaller teeth.
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But as human cultures and occupations became more diverse and specialized,
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so did our friends.
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Short stocky dogs to herd livestock by nipping their heels;
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elongated dogs to flush badgers and foxes out of burrows;
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thin and sleek dogs for racing;
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and large, muscular dogs for guard duty.
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With the emergence of kennel clubs and dog shows during England’s Victorian era,
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these dog types were standardized into breeds,
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with many new ones bred purely for appearance.
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Sadly, while all dog breeds are the product of artificial selection,
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some are healthier than others.
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Many of these aesthetic characteristics come with congenital health problems,
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such as difficulty breathing or being prone to spinal injuries.
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Humanity’s longest experiment in controlled evolution
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has had other side effects as well.
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Generations of selection for tameness
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have favored more juvenile and submissive traits
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that were pleasing to humans.
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This phenomenon of selecting traits associated with youth is known as neoteny,
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and can be seen in many domestic animals.
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Thousands of years of co-evolution may even have bonded us chemically.
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Not only can canines understand our emotions and body language,
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but when dogs and humans interact,
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both our bodies release oxytocin;
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a hormone commonly associated with feelings of love and protectiveness.
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It might be difficult to fathom how every Pomeranian, Chihuahua, and Poodle
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are descended from fierce wolves.
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But the diversity of breeds today is the result of a relationship
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that precedes cities, agriculture,
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and even the disappearance of our Neanderthal cousins.
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And it’s heartening to know
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that given enough time,
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even our most dangerous rivals can become our fiercest friends.
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