CELPIP Reading Part 3 Practice Test: The Domestication Of Dogs

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Genetic and archaeological evidence indicates that dogs were domesticated from wolves at least 15,000 years ago, making them the first species domesticated by humans, well before the emergence of agriculture. Exactly where this initial domestication occurred remains disputed among researchers, with competing evidence pointing to Europe, Central Asia, and East Asia as possible origin points, and some scientists suspect domestication may have occurred independently in more than one region. Unlike most later domesticated animals, which were typically bred deliberately for specific purposes, dogs are widely believed to have domesticated themselves gradually, drawn toward human settlements by access to discarded food. This self-domestication process likely unfolded over many generations rather than through any single deliberate human decision.

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One influential theory suggests that wolves less fearful of humans gained a survival advantage by scavenging near early human camps, gradually becoming tamer with each generation as natural selection favoured friendlier individuals. Over many generations, this selection pressure is thought to have produced physical changes as a side effect, including floppier ears, curlier tails, and patchy coats, traits rarely seen in wild wolves but common among domestic dogs. A famous, decades-long experiment involving farmed foxes in Russia demonstrated that selecting only for tameness alone could reproduce many of these same physical traits within just a few generations. The change appeared without anyone selecting for looks at all. The relationships among these details matter as much as the individual facts themselves.

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As domestication proceeded, humans began actively selecting dogs for particular traits and functions, eventually producing the hundreds of distinct breeds recognized today, ranging from massive guardian breeds to toy breeds weighing only a few kilograms. This selective breeding intensified dramatically during the nineteenth century, when formal kennel clubs began establishing standardized breed descriptions and competitive dog shows became popular across Europe and North America. Critics argue that some of this selective breeding has since prioritized appearance over health, producing breeds prone to serious genetic disorders and reduced longevity. Popular new breeds soon spread between countries as enthusiasts exchanged breeding stock. Taken together, the separate details reveal a broader pattern while preserving the different limitations attached to each individual observation.

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Today, dogs occupy a uniquely intimate role in human society, employed in policing, disability assistance, search and rescue, and therapeutic settings, in addition to their enduring popularity as household companions. Researchers studying human-dog relationships have documented physiological changes in both species during positive interaction, including reduced levels of stress hormones in humans and elevated levels of bonding hormones in both species simultaneously. Some scientists argue that this close mutual relationship, refined over thousands of years, represents one of the most successful examples of interspecies cooperation in the natural world. Some researchers argue that this bond likely accelerated dogs' ability to read human social cues far more effectively than wolves ever could. This distinction remains important within the broader discussion.

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Not given in any of the above paragraphs.