Understanding the Nature of Dogs

Quck answer

Dogs are amazing animals that have been domesticated for thousands of years. They have a keen sense of smell, excellent hearing, and are very loyal to their owners. Dogs have a unique digestive system that allows them to eat a variety of foods, including meats, vegetables, and grains. They also have a complex nervous system that allows them to respond to their environment and interact with humans. Dogs are used for a variety of tasks, including hunting, herding, and as companions. Understanding how dogs work can help you better care for your furry friend and appreciate the special bond that you share.

Pets

A photograph of Bonnie, a Brindle Great Dane, with Sparkle, a Chihuahua mix. Ellen owns the photo.

History tells us that dogs were the first animals to be domesticated by humans, and this relationship goes back at least 15,000 years. Dogs have been serving humans in various roles and performing many jobs. Regardless of their size or shape, from Great Danes to Chihuahuas, all dogs belong to the same species and have one basic history.

In this article, we will explore the origin of dogs and their behavior. We will also look at recent genetic studies that reveal important information about our furry friends. Additionally, we will discuss how to choose the right dog for you.

The Emergence of Dogs

Dogs belong to the family Canidae, which is a part of a larger group called Carnivora. Other members of Carnivora include cats, bears, and seals. Fossils suggest that Canidae branched off from the common ancestors of Carnivora around 40 million years ago. From 15 million years ago to the present, Canidae can be divided into three subgroups: fox-like animals, wolf-like animals, and South American canids such as the maned wolf and crab-eating fox. Wolves, coyotes, and jackals, which are closely related, belong to the wolf-like group.

Many scientists believed that dogs descended from different types of wild canids due to the diversity of dogs and wild canids. However, recent DNA analyses reveal that dogs are only descended from wolves.

In the following section, we will investigate how this evolution happened.

The Domestication of Wolves

A photograph of newborn dogs who are blind, deaf, and dependent on their mother, just like wolf puppies. Hannah Harris owns the photo.

Although it is evident that dogs descended from wolves, how this occurred is still unclear. The widespread view is that prehistoric people took wolf pups from their dens and raised them to believe that humans were their “pack.” These wolves lived with people, mated, and produced offspring. People selected wolf-dogs with unique coats or heavier bone structure, which would have been fatal in the wild. Over time, people selectively bred these wolf-dogs until they produced the diversity of dogs that we see today.

However, this theory has a flaw. Due to the uniform appearance of wolves, it is unlikely for a mutation to appear randomly in a captive population. It would take thousands or even millions of years to produce much variety. Nevertheless, fossil evidence suggests that dogs appeared relatively recently. If dogs have only existed for 15,000 years, it is a minute amount of time in evolutionary terms. DNA evidence indicates that dogs may have started to diverge from wolves as early as 100,000 years ago, but this is still relatively recent. Nevertheless, dogs exhibit the most extreme physical diversity among all mammalian species. Dogs have more variation in size, color, coat texture, and other physical characteristics than all other members of the canid family.

So, how did it occur?

The book “Dogs: A Startling New Understanding of Canine Origin, Behavior, & Evolution” by Raymond and Lorna Coppinger challenges the traditional theory of how dogs evolved from wolves. The Coppingers propose that wolves “domesticated themselves” when humans transitioned from mobile hunter/gatherer societies to sedentary villages. This created a new ecological niche for neighboring wolves as humans produced food scraps and waste that became a valuable food source for animals. The boldest wolves survived the best by taking advantage of these resources and reproducing with each other, passing on their boldness to their offspring. This new group of wolves didn’t need to be large or strong like their ancestors, but rather small and tolerant of humans. Natural selection played a significant role in this evolution process. In contrast, studies with captive wolves show that they are extremely difficult to train, even if they have been captive bred for generations. In the next section, the article explores how both natural and artificial selection led to the evolution of the modern dog.

Artificial selection is a process where humans choose the traits that are passed down instead of the “survival of the fittest” principle. These traits may or may not be directly beneficial to the animal, but they are the ones that humans choose to breed. For example, bulldogs have been selectively bred for increasingly larger heads, resulting in many puppies being born via Caesarean section. Russian scientist Dmitri Belyaev conducted studies on silver foxes, selectively breeding those that were more tolerant of humans. Over the generations, the foxes became tamer and developed strange physical characteristics, similar to those seen in dogs. The theory is that selecting for friendlier animals affects some aspects of the developmental process, resulting in animals that are more puppy-like in their behavior and physical appearance. This may have also occurred in wolves, creating a population of smaller, friendlier wolves with various physical characteristics. Pariah dogs on the margins of society are an example of the original dog type, evolved from wolves to take advantage of the niche that humans provide. Artificial selection continues to create new dog breeds.

In both theories of the evolution of dogs, it is believed that they became dogs due to their association with humans. However, a new theory suggests that groups of wolves evolved into dogs via natural selection, making dogs a unique species shaped by the same process that created other canids. The idea of viewing dogs as substandard wolves created by humans may lead to misunderstanding and underestimating them. People initially thought that dogs could be useful for more than just eating trash. They bark to warn each other of intruders and have superior senses of smell and hearing that make them better at spotting prey. Dogs have evolved differently from wolves, as they do not need all the predatory behaviors to survive. People have selectively bred dogs, emphasizing certain traits and downplaying or eliminating others, depending on their purpose. The genetic frequency for desired qualities goes up in each generation, and traits can be fixed in just a few generations. Certain dog types are called “breeds.” Dogs use certain predatory behaviors to perform their tasks, such as herding or retrieving, but they do not have the full set of predatory behaviors that wolves have. Dogs are better than wolves at performing their particular task.

To be classified as a breed, dogs must have a history of breeding for several generations and produce offspring that are relatively uniform. Each recognized breed has a standard that describes the ideal appearance and behavior, including coat color and texture, stance, and attitude. While not all purebred dogs will meet the standard, reputable breeders strive to achieve it. Designer mixes and purebred dogs represent genetically closed populations, with purebred dogs having less genetic diversity due to bottlenecks and founder effects. Close breeding can lead to uniformity in appearance, but also increases the risk of genetic health problems. Cloning may offer a new direction for dog breeding in the future.

The latest trend in the world of dog breeding is the creation of designer mixes, where one purebred dog is bred with another of a different breed in order to produce offspring with the best qualities of both breeds and potentially eliminate any negative traits. One of the most popular designer mixes is the Labradoodle, which is a cross between a Retriever and a Poodle, and is said to possess the friendly and gentle nature of the Retriever, as well as the low-shedding attributes of the Poodle.

The principles of Mendelian genetics, developed by Gregor Mendel in the 19th century using pea plants, also apply to dogs. In this case, a particular gene on a specific locus determines each trait, such as whether the coat is straight or curly. The variations in the DNA sequence of this gene are called alleles, and an individual dog inherits one allele from each parent. Dogs that are closely bred tend to be homozygous at the loci that determine coat type, but when a homozygous dog is bred with a different homozygous dog, their offspring will all be heterozygous.

However, breeding two Labradoodles together will not produce Labradoodle offspring, as they are not a pure breed. Instead, the resulting puppies will be a mix of both breeds, with some resembling Labs and others resembling Poodles. It’s important to note that hereditary problems like hip dysplasia are present in both breeds and cannot be eliminated through cross-breeding.

In addition to Labradoodles, there are many other designer mixes out there, each with their own unique traits and characteristics. It’s important to do thorough research before adopting any type of dog, and to always prioritize the health and well-being of the animal.

The breeding of dogs has led to a variety of purposes. Some breeds, like lap dogs, were bred for companionship while others were bred for activity such as herding and pulling sleds. Dogs that were bred to pull sleds enjoy their job as it is genetically programmed in them to do so. However, it becomes difficult to train them to heel as it goes against their breeding. Dogs often end up in shelters and rescue groups because they were bred to do something that their owners did not need them for. For instance, an Australian shepherd that does not have sheep may try to herd children, cats or even pinecones. This may lead to problems as children and cats do not like to be herded. It is important to research a dog’s breed and background before adding them to the household. A dog show is like a beauty contest where judges judge how closely the dogs resemble their breed standards, but they aren’t judged on the job they were bred to do. Some dog breeds have diverged into “show” lines and “working” lines.

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Picking a Canine

When selecting a dog, it’s important to consider how the new addition will fit in with the rest of the family.
Photo courtesy Hannah Harris

If you have certain expectations for your new dog, it’s important to learn about what their ancestors were bred for. A German Shepherd whose parents and grandparents excelled at Schutzhund will have a temperament and energy level that differs greatly from one whose family were primarily pets.

Even within a specific breed, there are variations in individual dogs that represent the breed’s emphasized characteristics to a greater or lesser extent. A breed rescue may be a good option, as purebred dogs are carefully evaluated for their energy level and drive. Alternatively, a mixed breed dog may be more suitable for your lifestyle.

Responsible breeders and rescuers put in a lot of effort to help match people with the right dog based on their personality and lifestyle. They know that a dog who has their energy and intellectual needs met will be happy and well-behaved.

The best dog for one person may not be the best fit for someone else. It’s important to avoid breeders who prioritize making a profit over producing quality dogs for appropriate homes. Profit-driven dog breeding is controversial, as there are already more dogs than there are available homes. Additionally, breeding responsibly is expensive, so making a profit may indicate shortcuts being taken somewhere along the line. To learn more about choosing a responsible breeder, refer to the links in the next section.

The relationship between humans and dogs is extensive and longstanding. Dogs are involved in more aspects of human society and culture than any other species. There are over 350 recognized breeds, countless mixed breeds, and dogs that aren’t part of any breed. Dogs can find lost people, detect drugs and explosives, guide the blind, herd and protect livestock, provide comfort to the sick, and even detect certain types of cancer. Most importantly, dogs enrich our lives and we share a special bond with them. Knowing more about dogs can help you find the right one or better understand and appreciate the dog you already have.

To learn more about what dogs do or how to choose the right dog for your lifestyle, refer to the links in the next section.

Jenkins reflects on life as a dog.
Photo courtesy Harris
The Shelter Situation

The Humane Society of the United States estimates that 3 to 4 million cats and dogs are euthanized in shelters every year due to a lack of available homes.

Spaying or neutering your pet is important (if cost is a concern, check out the HSUS website for assistance). If you’re considering adding a new dog to your family, consider adopting from a shelter or rescue group.

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Additional Information

Related Articles

• Learning about Evolution
• The Science of Cloning
• Understanding Gene Pools

• Training Guide Dogs
• How Search-and-rescue Dogs Help

More Useful Links

• The Humane Society of the United States
• Petfinder.com
• Choosing the Perfect Dog
• Finding a Trustworthy Breeder
• The American Kennel Club

Sources

• Beck, Alan M. “The Ecology of Stray Dogs: A Study of Free-Ranging Urban Animals.” Baltimore: York Press, 1973.
• Belyaev, D.K. “Destabilizing Selection as a Factor in Domestication.” Journal of Heredity, vol. 70, pp. 301-308, 1979.
• Clutton-Brock, J. “Origins of the dog: Domestication and early history.” From “The Domestic Dog: Its Evolution, Behavior, and Interactions with People.” edited by J. Serpell. Cambridge, UK: Cambridge University Press, 1995.
• Coppinger, R. & Coppinger, L. ” Dogs: A Startling New Understanding of Canine Origin, Behavior & Evolution.” New York: University of Chicago Press, 2001.
• Ellegren, H. “The dog has its day.” Nature, vol. 438 pp. 745-746, 2005.
• Fox, M. “Behavior of Wolves, Dogs and Related Canids.” New York: Harper-Row, 1971.
• Trut, L.N. “Early Canid Domestication: Farm Fox Experiment.” American Scientist, vol. 87 pp. 160-169, 1999.
• Trut, L.N. “An Experiment on Fox Domestication and Debatable Issues of Evolution of the Dog.” Russian Journal of Genetics, vol. 40 pp. 644-655, 2003.
• Vila, C. et al. “Multiple and Ancient Origins of the Domestic Dog.” Science, vol. 276 pp. 1687-1689, 1997.

FAQ

1. What makes dogs such great companions?

Dogs have been domesticated for thousands of years and have evolved to be highly attuned to human emotions and behavior. They are loyal, affectionate, and can provide a sense of security and comfort. Dogs also offer many benefits to their owners, such as reducing stress and anxiety, increasing physical activity, and providing a sense of purpose and responsibility.

2. How do dogs communicate?

Dogs communicate through body language, vocalizations, and scent. They use various postures and movements to convey emotions such as fear, aggression, or submission. They also use vocalizations such as barking, growling, and whining to communicate their needs and emotions. Dogs also rely heavily on scent, using their sense of smell to gather information about their environment, other animals, and humans.

3. What is a dog’s sense of smell like?

A dog’s sense of smell is highly developed and is estimated to be up to 100,000 times more powerful than a human’s sense of smell. Dogs have about 300 million olfactory receptors in their noses, compared to humans who have only about 6 million. This allows them to detect even subtle changes in scent and to distinguish between different odors. Dogs also have a specialized organ in their noses called the vomeronasal organ, which allows them to detect pheromones and other chemical signals.

4. How do dogs learn?

Dogs learn through a combination of experience, repetition, and reward-based training. They are highly adaptable and can learn to perform a wide range of tasks, from basic obedience commands to complex tasks such as search and rescue or detection work. Dogs also learn through socialization, which involves exposure to a variety of people, animals, and environments during their early development.

5. What is a dog’s memory like?

Dogs have a relatively short-term memory, meaning they can remember events and experiences for a short period of time, usually a few minutes or hours. However, they have an excellent ability to remember and associate specific scents with certain experiences, which is why they are often used in scent detection work. They also have the ability to remember routines and habits that are reinforced through repetition and reward-based training.

6. How do dogs see the world?

Dogs see the world differently than humans. They have a wider field of vision and see better in dim light, but their visual acuity is not as sharp as humans. Dogs are also able to see some colors, but their range of color vision is limited compared to humans. They rely more heavily on their sense of smell and hearing to navigate their environment.

7. How do dogs show affection?

Dogs show affection in a variety of ways, such as licking, nuzzling, leaning, and wagging their tails. They also enjoy physical contact, such as being petted or cuddled. Dogs may also bring their owners toys or treats as a sign of affection. Each dog has its own unique way of showing affection, and it’s important for owners to understand and respond to their dog’s individual needs.

8. What is a dog’s sleep pattern like?

Dogs typically sleep for a total of 12-14 hours per day, but this can vary depending on their age, breed, and activity level. Dogs often take short naps throughout the day, but most of their sleep occurs at night. They also tend to sleep in short cycles, with periods of deep sleep followed by periods of light sleep or wakefulness.

9. How do dogs stay cool in hot weather?

Dogs have a few strategies for staying cool in hot weather. They may pant, which helps to evaporate moisture from their tongue and upper respiratory tract and helps to cool their body. Dogs may also seek out shade or cool surfaces to lie on, or they may take a dip in water to cool off. It’s important for owners to provide their dogs with plenty of fresh water and to avoid exercising their dogs during the hottest parts of the day.

10. What are some common health issues for dogs?

Dogs are susceptible to a variety of health issues, including obesity, dental problems, allergies, ear infections, and skin conditions. Some breeds are also prone to specific health issues, such as hip dysplasia or respiratory problems. It’s important for owners to provide their dogs with regular preventative care, including vaccinations, parasite control, and dental cleanings, and to monitor their dogs for any signs of illness or injury.