Domestic Dogs, Domestic Dog Pictures, Domestic Dog Facts - National Geographic Size relative to a 6-ft (2-m) man Please add a "relative" entry to your dictionary. Dogs were probably the first tame animals. They have accompanied humans for some 10,000 years. Some scientists assert that all dogs, domestic and wild, share a common ancestor in the small South Asian wolf. Today humans have bred hundreds of different domestic dog breeds—some of which could never survive in the wild. Despite their many shapes and sizes all domestic dogs, from Newfoundlands to pugs, are members of the same species—Canis familiaris. Although they have domestic temperaments, these dogs are related to wolves, foxes, and jackals. Domestic dogs still share many behaviors with their wild relatives. Both defend their territories and mark them by urinating on trees, rocks, fence posts, and other suitable sites. These scent posts serve notice to other dogs that an animal is occupying its territory. Many pet dogs also bury bones or favorite toys for future use, just as their wild relatives sometimes bury a kill to secure the meat for later feasts. Dogs communicate in several ways. Scent is one method, another is physical appearance.

Body position, movement, and facial expression often convey a strong message. Many of these signals are recognizable even to humans, such as the excited tail-wagging of a happy dog or the bared teeth of an angry or threatened animal. Vocally, dogs communicate with a cacophony of sounds including barks, growls, and whines. Domestic dogs serve as more than companions; many earn their keep by working hard. Dogs herd livestock, aid hunters, guard homes, and perform police and rescue work. Some special animals even guide the blind—a poignant symbol of the dog's longstanding role as man's best friend. Why are different breeds of dogs all considered the same species? - Scientific American Scientific American Why are different breeds of dogs all considered the same species? By Nikhil Swaminathan on March 5, 2008 Advertisement | Report Ad Full question: How come some similar animals are different species, while with domestic dogs, wildly dissimilar types are considered different breeds? -- Z. Kornberg, Jerusalem Michael Bruford, a professor of biological sciences at Cardiff University in Wales, explains the thought process behind this seeming double standard.

Scientists have been distinguishing between species on the basis of how they look, behave or live since recorded history began. However, two famous scientists stand out in terms of how we perceive species differences today: Carl Linnaeus, an 18th-century Swedish naturalist, and Charles Darwin. Linnaeus was the first person to formulate a single approach for describing species in a hierarchical manner according to their similarity, using his binomial nomenclature of genus followed by species (Homo sapiens, for instance). Darwin was among the first people, and certainly the most celebrated among them, to develop a credible theory on how species evolve (via natural selection). Both of these scientists' insights underpin most of what modern science utilizes when studying species and speciation. Currently species are still primarily distinguished by their appearance, but it is becoming very clear that looks don't always tell us all we need to know about whether two organisms are different. Many so-called cryptic species exist that, to the untrained eye, look very similar or even identical to another organism--commonly found, for example, in nocturnal mammals such as bats and bush babies.

If the two mated, however, they may never be able to produce viable offspring; this, in fact, is the primary criterion for dividing similar organisms into different species. Because of these red herrings--and also because the process of describing species is very long and labor-intensive--scientists are increasingly turning to DNA to assist them in identifying and describing species. Indeed, there is an endeavor under way at the moment called the Barcode of Life project, which aims to sequence all living organisms for a single gene that is common to them all, to produce a species "bar code." The key is that the sequence must vary greatly among species but not vary much within species. Such a bar code can then be used to identify organisms which may not be easily identified (such as tracing back what primate was the source of mysterious smoked meat in the rainforest) and even to distinguish organisms such as microbes that we cannot see or culture in the laboratory. There has been much debate among scientists about which DNA sequence is best for this purpose, and it is likely that a different sequence will work for each different kingdom of organisms.

Currently a small gene found in the mitochondrial DNA of our cells--the cytochrome oxidase subunit 1 gene--is most commonly used in identifying members of the kingdom Animalia; a huge database is already in place for many of the world's animals using this gene. Domestic animals fascinated Darwin and continue to enthrall those of us who own pets. It is certainly curious how domestic dogs, which we know--because DNA bar coding has told us!--were raised by man from a wild gray wolf (Canis lupus) ancestor, can take on such a dramatic variety of forms. But among dogs, which are well known for their hybrid (or mongrel) varieties, different breeds can mate and have viable offspring, so they are all found under the umbrella of a single species, Canis familiaris. Dogs are highly unusual in their variation, from the Chihuahua to the Great Dane. (Recently, body size was found to be largely explained by differences in a single gene among dog breeds.) Darwin realized that man can force selection by picking particular individuals for breeding who show a particular characteristic that we want to see in our pets.

So humans can accelerate the process of selection dramatically by exploiting the diversity naturally found in domestic forms and homing in on a form that is desirable. Natural selection usually acts more slowly, relying on what Darwin described as "descent with modification"--the chance arrival of new forms through DNA mutation. domestication - National Geographic Society domestication Only domesticated animals wear hats. Photograph by Jodi Cobb Wild Horses The process of domestication continues. Cowboys and other horse experts train horses. Sometimes, this is called "breaking" a horse. Training a horse to allow a saddle and rider requires an enormous amount of physical work, training, and patience. Horses that are born on ranches or in stables still need to be trained, although training a young horse is easier than domesticating a horse caught in the wild. Dogs and Wolves Though today's dogs were likely domesticated from gray wolves, they are now a distinct species. Dogs' scientific name is canis lupus familiaris, while the scientific name for gray wolves is canis lupus. Domestication is the process of adapting wild plants and animals for human use. Domestic species are raised for food, work, clothing, medicine, and many other uses.

Domesticated plants and animals must be raised and cared for by humans. Domesticated species are not wild. Plant Domestication People first domesticated plants about 10,000 years ago, between the Tigris and Euphrates rivers in Mesopotamia (which includes the modern countries of Iran, Iraq, Turkey, and Syria). People collected and planted the seeds of wild plants. They made sure the plants had as much water as they needed to grow, and planted them in areas with the right amount of sun. Weeks or months later, when the plants blossomed, people harvested the food crops. The first domesticated plants in Mesopotamia were wheat , barley , lentils, and types of peas. People in other parts of the world, including eastern Asia, parts of Africa, and parts of North and South America, also domesticated plants. Other plants that were cultivated by early civilizations included rice (in Asia) and potatoes (in South America). Plants have not only been domesticated for food. Cotton plants were domesticated for fiber , which is used in cloth. Some flowers, such as tulips, were domesticated for ornamental , or decorative, reasons.

Animal Domestication About the same time they domesticated plants, people in Mesopotamia began to tame animals for meat, milk, and hides. Hides, or the skins of animals, were used for clothing, storage , and to build tent shelters. Goats were probably the first animals to be domesticated, followed closely by sheep . In Southeast Asia, chickens also were domesticated about 10,000 years ago. Later, people began domesticating larger animals, such as oxen or horses, for plowing and transportation . These are known as beasts of burden. Domesticating animals can be difficult work. The easiest animals to domesticate are herbivores that graze on vegetation, because they are easiest to feed: They do not need humans to kill other animals to feed them, or to grow special crops. Cows, for instance, are easily domesticated. Herbivores that eat grains are more difficult to domesticate than herbivores that graze because grains are valuable and also need to be domesticated. Chickens are herbivores that eat seeds and grain . Some animals domesticated for one purpose no longer serve that purpose. Some dogs were domesticated to assist people in hunting, for instance.

There are hundreds of domestic dog species today. Many of them are still excellent hunters, but most are pets. Throughout history, people have bred domesticated animals to promote certain traits. Domestic animals are chosen for their ability to breed in captivity and for their calm temperament . Their ability to resist disease and survive in difficult climates is also valuable. Over time, these traits make domestic animals different from their wild ancestors. Dogs were probably domesticated from gray wolves. Today, dogs are a distinct species from gray wolves. Domesticated animals can look very different from their wild ancestors. For example, early wild chickens weighed about two pounds. But over thousands of years of domestication, they have been bred to be larger. Larger chickens yield more meat. Today, domestic chickens weigh as much as 17 pounds. Wild chickens only hatched a small number of eggs once a year, while domestic chickens commonly lay 200 or more eggs each year. Effects on Humans Domesticating plants marked a major turning point for humans: the beginning of an agricultural way of life and more permanent civilizations. Humans no longer had to wander to hunt animals and gather plants for their food supplies. Agriculture —the cultivating of domestic plants—allowed fewer people to provide more food.

The stability that came with regular, predictable food production led to increased population density . People were able to do more than hunt for each day’s food—they could travel , trade , and communicate . The world's first villages and cities were built near fields of domesticated plants. Plant domestication also led to advances in tool production. The earliest farming tools were hand tools made from stone. People later developed metal farming tools, and eventually used plows pulled by domesticated animals to work fields. Term to adjust to new surroundings or a new situation. agriculture Noun organism from whom one is descended. animal Noun organisms that have a well-defined shape and limited growth, can move voluntarily, acquire food and digest it internally, and can respond rapidly to stimuli. barley grass cultivated as a grain. beast of burden animal used for carrying or pulling heavy loads. break to tame a horse, or make it comfortable with a saddle and rider. breed domestic bird cultivated for meat, eggs, and feathers. city large settlement with a high population density. civilization to exchange knowledge, thoughts, or feelings. cotton cloth made from fibers of the cotton plant. cow large, domesticated mammal used for milk and meat.

cowboy person who herds cattle on a ranch, usually on a horse. crop domestic animal related to the wolf. domestication long, thin, threadlike material produced by plants that aids digestive motion when consumed. goat hoofed mammal domesticated for its milk, coat, and flesh. grain to feed on grass, usually over a wide pasture. grey wolf mammal related to the dog. harvest the gathering and collection of crops, including both plants and animals. herbivore leather skin of an animal. horse type of domesticated mammal used for riding and hauling. hunt to pursue and kill an animal, usually for food. lentil plant with small, flat seeds, native to Asia. Mesopotamia area between the Tigris and Euphrates River in Iraq. metal category of elements that are usually solid and shiny at room temperature. ornamental decorative or presented for beauty. patience ability to deal with pain, misfortune, or annoyance without complaint. pea plant with a pod bearing small, round seeds. permanent organism that produces its own food through photosynthesis and whose cells have walls. plow tool used for cutting, lifting, and turning the soil in preparation for planting.

population density the number of people living in a set area, such as a square mile. potato plant native to the Americas. predictable regular or able to be forecasted. process natural or human actions that create and change the Earths features. ranch large farm on which livestock are raised. resist grass cultivated for its seeds. saddle seat for a rider on a horse. seed part of a plant from which a new plant grows. sheep type of mammal with thick, strong wool used for cloth. shelter structure that protects people or other organisms from weather and other dangers. stable building where horses or other animals are kept. storage space for keeping materials for use at a later time. tame to domesticate or make useful for humans. temperament traits or personality of an individual. tool instrument used to help in the performance of a task. trade buying, selling, or exchanging of goods and services. trait movement of people or goods from one place to another. travel movement from one place to another. tulip colorful, cup-shaped flower native to Asia. village most widely grown cereal in the world.

wild Origin of Domestic Dogs | The Scientist Magazine® Origin of Domestic Dogs New analysis suggests that domestic dogs evolved from European wolves that interacted with human hunter-gatherers. By Ed Yong | November 14, 2013 Gray wolfWIKIMEDIA, MARTIN MECNAROWSKI Domestic dogs evolved from a group of wolves that came into contact with European hunter-gatherers between 18,800 and 32,100 years ago and may have since died out. This origin story comes from a new study that compares DNA from dozens of dogs and wolves, including 18 ancient fossils. The results, published today (November 14) in Science, provide the clearest picture yet of where, when, and how wild predators came to be man’s best friend. “It really is a sea change from the little bits of fragmentary DNA that have been reported in the past,” said Gregor Larson from Durham University in the U.K., who was not involved in the study. “It includes really old material from a wide range of sites.” The new paper follows two earlier studies that looked at the genetic signatures of domestication in dogs, and came to differing conclusions about canine origins.

One group suggested that dogs were domesticated around 10,000 years ago during the Agricultural Revolution, when wolves started scavenging human scrap heaps. Another concluded that wolves and dogs split 32,000 years ago, somewhere in East Asia. Both studies compared the genes of a wide variety of living dogs and wolves, but modern samples can be deceptive. Dogs and wolves diverged so recently that many of their genes have not had time to separate into distinct lineages. They have also repeatedly hybridized with each other, further confusing their genealogies. To deal with these problems, a team led by Olaf Thalmann from the University of Turku in Finland analyzed mitochondrial DNA from 18 fossil canids. They compared these ancient sequences to those from 49 modern wolves and 77 modern dogs, and built a family tree that charts their relationships. The tree conclusively pinpointed Europe as the major nexus of dog domestication. It identified four clades of modern dogs, which are all most closely related to ancient European canids rather than wolves from China or the Middle East. “We didn’t expect the ancestry to be so clearly defined,” Thalmann told The Scientist.

“This suggests that the population of wolves in Europe that gave rise to modern dogs may have gone extinct, which is plausible given how humans have wiped out wolves over the centuries,” he added. According to this new tree, the largest clade of domestic dogs last shared a common ancestor 18,800 years ago, and collectively, they last shared a common ancestor with a wolf around 32,100 years ago. They must have been domesticated at some point during this window. These molecular dates fit with fossil evidence. The oldest dog fossils come from Western Europe and Siberia, and are thought to be at least 15,000 years old. By contrast, those from the Middle East and East Asia are believed to be 13,000 years old, at most. “The archaeologists would be happy,” said Larson. The dates also make it unlikely that dogs were domesticated during the Agricultural Revolution, which took place millennia later. Instead, they must have first associated with European hunter-gatherers. They may have assisted humans in bringing down large prey, or could simply have scavenged leftover carcasses. Either way, their association with humans grew stronger and stronger, until they eventually evolved into domestic dogs.

However, Thalmann acknowledged that his team’s analysis does not include any ancient DNA from the Middle East or China, nor nuclear DNA from any of the fossils. In other ancient DNA studies, nuclear DNA sequences have revised the evolutionary stories told by mitochondrial ones. “Who knows what we would find if we had ancient canid samples from East Asia or elsewhere, or were successful in amplifying nuclear DNA from ancient canids,” said Adam Boyko from Cornell University, who was not involved in the study, via email. “But that shouldn't detract from the great work they were able to do here,” he added. Larson cautioned that the paper is not the final word on canine origins. “It would be a mistake to jump and say that dogs were domesticated in Europe and not anywhere else,” he said. “We know pigs were domesticated independently in China and Turkey, so there’s no thinking that dog domestication had to happen in just one place.” Indeed, Thalmann’s team showed that the famous Goyet dog —a 36,000 year old Belgian skull, supposedly belonging to the oldest known dog—is not directly ancestral to modern dogs. Instead, it represents an ancient sister lineage that died out.

The same is true for other old specimens from Belgium and Russia’s Altai Mountains. “Maybe they were trial domestications that were not successful,” said Thalmann. O. Thalmann et al., “Complete mitochondrial genomes of ancient canids suggest a European origin of domestic dogs,” Science, doi:10.1126/science.1243650, 2013. 14 of Your Dog's Wild Relatives | Mental Floss 14 of Your Dog's Wild Relatives Image credit: Like us on Facebook All the domestic breeds of dogs that we are familiar with, from chihuahuas to pit bulls, are the same species: Canis lupus familiaris. In fact, our dogs are a subspecies of Canis lupus, or wolf. Your dog could interbreed with most wolves -if you weren't a responsible pet owner who spayed or neutered your dog. Photograph by Flickr user Fatemeh . Dogs belong to the taxonomic family Canidae (canines) which is divided into two tribes: those related to wolves (Canini) and those related to foxes (Vulpini).

A couple of canine species lay outside these two tribes, but hyenas are not canines. They look like and act like dogs, but as we learned in a post last week , hyenas are more closely related to cats than to dogs! Let's look at some wild dogs that are related to your pet. 1. Gray Wolf The species Canis lupus covers a lot of dogs. There are 39 subspecies , one of them being all domestic dog breeds. Thirty-seven of these subspecies are wolves, the largest and most common being the Eurasian gray wolf (Canis lupus lupus), the common ancestor of domestic dog breeds. The gray wolf is found throughout the Northern Hemisphere and comes in black, brown, grey, and white, or a combination of these colors. It is not considered to be a threatened species, but is protected in some areas. Photograph by Flickr user BBM Explorer . 2. Arabian Wolf Quite a few wolf subspecies look like the common gray wolf, but a few are strikingly different. The Arabian wolf (Canis lupus arabs) evolved to live in the deserts of the Middle East, which is why its hair is so short.

The fur varies over time according to the season and local temperatures. Photograph by Wikipedia user ???? ????? . 3. Arctic Wolf The Arctic wolf (Canis lupus arctos) is pretty much just a wolf that lives in the Arctic. The subspecies has adapted to its habitat by growing thick white fur that grows longer between the toes to protect its footpads and shorter ears and snout to conserve heat. Photograph by Flickr user dankos-unlmtd . 4. Coyote Coyotes (Canis latrans) are a species that has evolved as a canine predator but subsists alongside civilization better than most wolves. With less fear of humans, they've learned to help themselves to livestock, or will scavenge for garbage if no easy prey is available. However, we know at least one who is obsessed with a certain desert bird. Photograph by Flickr user Jean-Guy Dallaire . 5. Jackal There are three Canis species classified as jackals, or Old World coyotes. Shown here is a black-backed jackal (Canis mesomelas) which is native to several areas of Africa.

The side-striped jackal (Canis adustus) and the golden jackal (Canis aureus) are the other two species. Jackals are predators, but are also scavengers like the coyote, and while they prefer fresh meat, will eat anything available. Photograph by Wikipedia user Raoulduke47 . 6. Dingo The subspecies of Canis lupus that is neither domestic nor a wolf is Canis lupus dingo . However, there is some argument that dingos are indistinguishable from domestic dogs except for the fact that they are not domestic. The subspecies covers the Australian dingo plus some feral dogs of Asia such as the New Guinea Singing Dog . The Australian dingo is descended from domestic dogs that were brought to the island thousands of years ago which became feral over many generations. The dingos of Australia still interbreed with more recent domestic dogs, and so the subspecies is considered "vulnerable." Photograph by Flickr user Michael Dawes . 7. Dhole The dhole (Cuon alpinus) of Asia is a dog of the Caninae family and Canini tribe, but has its own genus.

You would recognize this creature as a dog, but it has more teats and fewer teeth than Canis, and whistles more than it barks or howls. They live in the forests and steppes of Russia, the Himalayas, and even as far south as Java. The biggest number of these endangered dogs live in India. Photograph by Flickr user Amit Kotwal . 8. Red Fox The other tribe of dog is the fox, or Vulpes. When we think of foxes, the image that comes up is usually the common red fox (Vulpes vulpes) which lives all over the Northern Hemisphere, plus Australia. It is the largest of the true foxes. Despite its name, it comes in varying colors, and there are 45 recognized subspecies. Photograph by Flickr user Brad Smith . 9. Kit Fox The kit fox (Vulpes macrotis) is native to the deserts of the western United States and Mexico. Its skinny body and large ears are adaptive to desert life, like the coyotes it somewhat resembles. There are eight subspecies of kit fox, mostly named after their habitats, like the San Joaquin Kit Fox (Vulpes macrotis mutica). 10.

Arctic Fox The Arctic fox (Vulpes lagopus) is sometimes classified as Alopex lagopus , which is an older classification that taxonomists still quarrel about. The lagopus sounds like a relation to rabbits, but in this case it refers to the fur that grows between the fox's toes to help protect them from cold surfaces. The Arctic fox could be mistaken for other fox species when seen in summer. Photograph by Flickr user Billy Lindblom . But this fox is very sensitive to seasonal changes, and will grow the thick warm white coat that made it famous by winter. Photograph by Flickr user Denis-Carl Robidoux . 11. Fennec Fox The fennec fox (Vulpes zerda) takes the desert adaptation of large ears used to dissipate heat to the max. The small nocturnal fox lives in the upper Sahara where heat dissipation is of the utmost importance. At just a couple of pounds and 9 to 16 inches long, the fennec fox is the world's smallest canid species (toy dog breeds are not representative of the species). Fennec foxes are sometimes kept as pets. Photograph by Flickr user Joachim S. Müller . 12.

Island Fox and Gray Fox Urocyon is a genus of foxes that climb trees. The island fox (Urocyon littoralis), also called the Channel Island fox, is barely bigger than a fennec fox. The only other existing Urocyon species is the slightly bigger gray fox (Urocyon cinereoargenteus). Photograph by Flickr user Robert Thompson. 13. Raccoon Dog The raccoon dog (Nyctereutes procyonoides) is of the Canidae family, but is neither a wolf nor a fox. It is not at all related to a raccoon, but may be mistaken for one. A distant cousin of your dog, the raccoon dog is still a closer relation than a hyena. Raccoon dogs are native to eastern Asia and are farmed for their fur. Photograph by Flickr user Dennis Irrgang . 14. Bat-eared Fox The bat-eared fox (Otocyon megalotis) is another member of the Canidae family that is neither a wolf nor fox (despite the name).

It is the only species of the genus Otocyon, and lives in the African savannah, eating insects -mostly termites. Its name comes from its distinctive big black ears. Photograph by Wikipedia user Samsara . More from mental_floss... How Many Dog Breeds Are There in The World | How Many Are There You Are Here: Home » Animals » How Many Dog Breeds Are There in The World How Many Dog Breeds Are There in The World Posted by: admin Posted date: April 06, 2012 In: Animals | Comment : 0 | 28,531 views There are over 500 breeds. All of them are not in the AKC or BKC though. There are around 600 including “designer doggie” breeds (such as a Puggle [pug + beagle] Pomapoo [pomeranian + poodle] and many MANY others. But, if you include ALL mixed breeds, then there is an infinite combination of anywhere from 2 breeds bred together…all the way to over 10s and 20s and 30s of breeds mixed! So, there is no TRUE answer to that question.

Just remember this about the mixed breeds (better known as mutts) Every Mutt Is Different, it is virtually impossible to ‘copy’ one single mutt.Here are some links showing puggles,pomapoos,& dorgis.Those are all “Designer Doggies”.

Dog breeds of the world list: Abruzzenhund American Black and Tan Coonhound American Blue Gascon Hound American Tundra Shepherd Dog (photos needed) American Water Spaniel Australian Stumpy Tail Cattle Dog Australian Terrier Austrian Black and Tan Hound Austrian Brandlbracke Basset fauve de Bretagne (photos needed) Basset Hound Cão da Serra da Estrela Cão da Serra de Aires Cão de Castro Laboreiro Cão de Fila de São Miguel Caravan Hound French White and Black Hound French White and Orange Hound Galgo Espanol Grand anglo-français blanc et noir Grand anglo-français blanc et orange Grand Basset Griffon Vendeen Irish Red and White Setter Irish Setter North American Miniature Australian Shepherd Northeasterly Hauling Laika Old-Time Farm Shepherd (photo needed) Olde Boston Bulldogge Pakistani Bull Dog (Gull Dong) Pakistani Bull Terrier (Pakistani Gull Terr) Pakistani Mastiff (Pakisani Bully Kutta) Pakistani Shepherd Dog (Bhagyari Kutta) Pakistani Tazi Hound (Photo Needed) Pakistani Vikhan Dog (Photo Needed) Panda Shepherd The Evolution and

 Domestication of the Dog - Responsible Dog and Cat, LLC Home Services Meet the Owner Dog Quiz Articles Photo Gallery In Memory Testimonials Rescue Contact The Evolution and Domestication of the Dog It is not hard to understand how many different ways dog’s companionship serves human needs today.

Dogs, resulting from domestication enjoy a truly unique status as companion animals. No other domestic animal enjoys the comfort and companionship afforded the dog. However, understanding how dogs achieved such unique status one might want to study evolution and domestication theories to explain how this remarkable relationship developed. There are differing views how dogs evolved and domestication occurred based on current evidence. The available evidence provided through academic studies of fossil remains, animal distribution, comparative anatomy, biology, and the natural environment has helped us understand how this process may have taken place. It is through these studies that we can draw better conclusions about the ancestry and domestication of the dog. The theories: how might the dog have evolved? Artificial selection suggests that early man was successful in taking wild wolf puppies: breeding them and eventually training them to perform tasks such as hunting and providing protection from other predators. These tame wolves selectively bred to more tame wolves eventually creating over thousands of years a new population now referred to as dogs. An anthropologist, Dr.

Colin Groves has suggested “…the human-dog relationship could be almost as old as modern man…basing his hypothesis on recent DNA research” and concluding “…humans domesticated dogs and dogs domesticated humans” (Perspectives in Human Biology, 1999). “Darwin described the evolution of life as a process of natural selection…a competitive struggle to survive.” Those able to survive with limited resources, competition for food and space, evading predators and disease; sustain unpredictable shifts in the environment, changes in climate, these individuals might possess characteristics that make them more likely to survive and reproduce (Encarta, 2004). In Darwin’s Origin of Species he says, “[c]an it, then, be thought improbable, seeing that variations useful to man have undoubtedly occurred, that other variations useful in some way to each being in the great and complex battle of life, should sometimes occur in the course of thousands of years?” He suggests, “…individuals having any advantage, however slight, over others, would have the best chance of surviving and of procreating their kind” (Darwin, 1859).

The evidence Archeological evidence Archeological evidence indicates the domestic dog has been around at least 14,000 years BP (before present) and that domestication probably began in Europe and western Asia. However, “[t]he archaeological record cannot resolve whether domestic dogs originated from a single wolf population or arose from multiple populations at different times…circumstantial evidence suggest that dogs may have diverse origins”, according to Wayne (Vila et al.,1997). Fossil remains from archeological sites in North China dating 300,000 years BP, a cave in south France dated at 150,000 years BP and a site in Kent, England dated at 400,000 years BP has provided evidence of bone fossils from early hominids and wolves located in close proximity. These sites provide possible evidence that a close relationship may have existed between early hominids and wolves prior to 14,000 years BP. What the exact relationship may have been still remains unclear.

However, according to Wayne and his associates at UCLA, domestication may have occurred as early as 100,000 years ago or more and early efforts of domestication may not have produced “significant morphological change in the protodog, thus explaining the absence of dog skeletal artifacts appearing before 14,000 years ago” (Vila et al.,1997). Wayne and his associates hypothesis states, “…domestic dogs may not have been morphologically distinct from their wild relatives…the change around 10,000 to 15,000 years ago from nomadic hunter-gatherer societies to more sedentary agricultural population centers may have imposed new selective regimes on dogs that resulted in marked phenotypic divergence from wild wolves” (Vila et al.,1997). Clutton-Brock agrees and says, “[t]hese tamed wolves were many generations away from the true domesticated dog, but they were its precursors.” Some of the fossil evidence shows “slight morphological differences from those of wild wolves”.

These slight differences include a “shortened facial region…compacted teeth…metapodial and toe bones…more slender than those of wolves.” This evidence provides slight anatomical differences, which may support Wayne’s theory (Serpell, Chapter 2, 1995). The earliest fossil evidence of domestication were found at sites in Oberkassel in Germany dating 14,000 years BP and a site in Israel dated to 12,000 years BP. The Israeli site, know as Ein Mallaha includes a burial site containing a skeleton of a puppy that had been buried with a human. Stone dwellings, evidence of grinding grain and tomb burials indicated the site was a permanent settlement. The fossil evidence indicates the inhabitants were likely early hunter-gatherers on the verge of becoming agriculturists. These permanent settlements likely provided the beginning of domestication of what we know today as the dog. The remaining question on the origin for the domestic dog remains unclear. However, Lindsay says, “the dog is a domestic wolf” but the exact origin of its predecessors remains debated. Some think the Indian Wolf (Canis lupis pallipes) is the most likely progenitor of the dog.

The conclusion based on a smaller size thus less threatening to early humans. Others have selected the Chinese Wolf (Canis lupus chanco) concluding the smaller size and mandible morphology supports, “the apex of the coronoid process turns back in both the Chinese wolf and the domestic dog but not in the jaw bone of other wolf species.” Still others have identified Canus lupus arabs, a western Asiatic wolf and the European wolf as the ancestor for most of the European breeds. According to the “genome of Arctic and European spitz-type breeds”, Canis lupus lupus has the greatest representation (Lindsay, 2000).

According to Clutton-Brock, “[t]he similarity in size and osteological characteristics of most of the remains of domestic dogs found on prehistoric sites in many different parts of the world may indicate that a small population of dogs diffused from a founder group in the early prehistoric period.” He maintains, “wolves must have been tamed and lived around human settlements in many parts of the world, and a single litter of puppies from any one of these could have provided the foundation stock for a large population of domestic dogs that subsequently became very widespread” (Serpell, Chapter 2, 1995). Based on fossil evidence, locations of archeological sites and comparative anatomy the early prototype dog likely received diverse genetic influence from several wolf species in different regions and during different times. Lindsay says, “…the biological ancestry of the dog is now certain…based on both genetic and behavioral studies the dog is a domestic wolf” and agrees the closest relative remains unknown (Lindsay, 2000).

According to Coppinger and Schneider, there are several views on the true origin of the dog, with the most common and accepted being that Canis lupus, is the “wild progenitor,” while still another suggests the wolf with “…some degree of hybridization with other members of the genus Canis, particularly jackals and coyotes contributed to the present day dog. Still another possibility suggests the dogs’ origin may have originated from other modern primitive breeds such as the Australian dingo, New Guinea singing dog and the Asiatic and African pariah dog. However, some consider the origin of the dog a mystery and therefore any speculation is “premature” (Serpell, Chapter 3, 1995). We can speculate the early progenitors were wolves and possibly included other members of the same species. According to taxonomy the wolf and dog are both members of the order Carnivora and classified in the family Canidae with coyotes, foxes, jackals, wolves and dogs and further classified in the Genus Canis, which includes wolves, jackals and dogs. All these members can interbreed and successfully produce offspring.

According to Serpell, “no other group in the animal kingdom has achieved such a diversity of form in so short a time as C. familiaris.” However, the “anatomical similarity” between the species does not provide the answer to the question of origin. According to Serpell, “…the real difference between them is behavioral: dogs are tamable and trainable, wild canids are not” (Serpell, 1995). Biological evidence Recent scientific discoveries in molecular biology and genetics have helped further explain how the dog may have evolved. To assist in explaining the biological process it might be helpful to understand a little about genetics. O’Heare provides the explanation as, “[a] genotype for a trait consists of the specific alleles that an individual possesses related to that trait…the term phenotype…describe[s] how that trait is expressed or displayed.” To explain this process further, O’Heare provided the following. The genotype is the genetic blueprint and provides the instructions for the organism to produce proteins, which then produce structures of the body. A genotype is the underlying genetic basis for a phenotype. The proteins interact with each other and with the environment to form larger, more complex structures. These proteins and structures are referred to as phenotypes.

They are the physical, observable traits produced by the genotype. The genotype (the blueprint) provides the potential for a range of possible phenotypes (the result you see). How this process helped the dog evolve is explained as “[w]hat is actually expressed within that range of potentiality will depend on how the environment interacts with the structures as they develop” (O’Heare, 2003). “Evolution refers to changes in allele frequencies within a population of organisms over time…that individuals do not evolve…populations evolve” and as a result “…allele frequencies within the population change from generation to generation” (O’Heare, 2003). Natural selection, O’Heare says, “…refers to the environmental influence on the reproductive success of some individual members of a population of organisms” and “…alleles from the reproductively successful organisms will be increased in the next generation and the alleles of the reproductively unsuccessful will alternatively decrease…variation in traits is common” (O’Heare, 2003).

Those individual traits affecting adaptability for a species might include “variable aggressiveness, size, confidence, and prey preference.” The more adaptable the trait, the more chance it will be passed on to the next generation. The “[a]daptive variations of traits are passed on at a greater rate than maladaptive traits…and with this inheritance come changes in the frequencies of the alleles involved from one generation to the next in the population.” This is what O’Heare refers to as evolution (O’Heare, 2003). However, Mitochondrial DNA studies have not conclusively proven the exact lineage the dog derived from. Therefore, any assumptions would be pure speculation. However, we can be certain that the most likely trait facilitating the domestication process was the dog’s willingness to accept and live in close proximity to humans. Evidence of domestication Without any clear fossil evidence that dogs existed prior to 14,000 years ago one can only presume early man had a relationship with tame wolves as early as 400,000 years ago or later. The archeological and scientific evidence does not support or prove whether man utilized wolves in any role or whether any close, relationship existed.

The Natufian burial site at Ein Mallaha, containing a woman clutching what appears to be a tame wolf or dog puppy has significant cultural value. Another Natufian burial site located in Israel contained a man with two adult canids identified as dogs. This archeological evidence provides proof of domestication and a much closer partnership to early hominids. Considering these finds it may be unlikely dogs were domesticated prior to approximately 14,000 years ago. What defines domestication? Clutton-Brock explains the domestication process as “two interwoven processes.” The first biological process resembles natural evolution where the “parent animals become reproductively isolated from the wild population and form a small founder group…that will at first be very inbred, and which will undergo a process of genetic drift.” These founder groups would increase and genetically change through natural selection due to environmental changes and human influences.

According to Clutton-Brock, “these tamed wolves would have become less and less like their wild forebears because inherently variable characteristics, such as coat colour, carriage of the ears and tail, over all size and the proportions of the limbs would have been altered by the combined effects of artificial and natural selection” (Serpell, Chapter 2, 1995). The second “cultural process” began when early humans took possession and integrated these early dogs into their societies. Clutton-Brock says, “…the wolf became a dog…it was no longer a wild carnivore but a part of human society with physical characteristics adapted to its economic, aesthetic or ritual functions…with the latest phase…individual ownership…was enforced with a collar and leash” (Serpell, Chapter 2, 1995). For a wild animal’s survival it is necessary to have a “high degree of perception…quick reactions to stress” and according to Clutton-Brock the opposite characteristics are necessary for domestic animals such as, “…docility, lack of fear and tolerance of stress” (Serpell, Chapter 2, 1995).

Biological and structural changes may take place, according to Clutton-Brock, such as “hormonal changes, reduction in size of brain, less acute sight and hearing, and the retention of juvenile characteristics and behavior into adult life” (Serpell, Chapter 2, 1995). Behavioral characteristics of domestication We know following the Ice Age, ending approximately fourteen-thousand years ago, Mesolithic societies “…began to gather for the first time in permanent settlements…coincidental with the first fossil evidence of dogs as we know them.” This created a “niche” for tamer wolves to domesticate themselves. Driven by a new and easily accessible food source, these tamer wolves may have been “genetically predisposed” having a lower threshold of “flight distance” thus enabling them a “selective advantage in the new niche over the wilder ones” (Coppinger, 2001). Lindsay describes the early relationship of humans and tame wolves as “mutualism” between the two species.

He says, “wolf-pack territories may have formed around human camps, thus providing a natural protective shield against the threat of predation by other less friendly wolves and competing human groups” resulting in “an ecological niche” which further facilitated the “protodog” to undergo “novel morphological and genetic changes gradually leading to domestic dogs” (Lindsay, 2000). This type of close contact, according to Lindsay, “requires that the animal in question possess a high fear threshold and a reduced tendency to flee, essential behavioral characteristics of domestication.” The “scientific evidence for a genetically divergent distribution of temperament traits based on relative tameness and confidence among canids has been demonstrated” by the Belyaev fox studies (Lindsay, 2000). According to these studies performed by Belyaev, he successfully bred “less fearful individuals” over several generations creating a tame “human friendly” fox. “Although a similar genetic basis for social tolerance has not been demonstrated in wolves,” it could reasonably be believed that a percentage of early wolves were less fearful and more tolerant of human presence.

This “adaptive behavioral polymorphism in wolves and its relevance to domestication have been discussed in detail by Fox (1971) and Scott” (Lindsay, 2000). It could be concluded from this evidence the single most significant trait “less fearful” contributed to what was described earlier by O’Heare as “…alleles from the reproductively successful organisms will be increased in the next generation and the alleles of the reproductively unsuccessful will alternatively decrease…variation in traits is common” (O’Heare, 2003). This single trait may have been all that was necessary to provide the tame wolf populations with what they needed to become more reproductively successful therefore passing on their genetic diversity. From this, we could conclude that based on the archeological and scientific evidence and the behavioral characteristics the ability to live in close proximity to human settlements provided the variation necessary to further facilitate the adaptation of the tame wolf populations to the ever changing environment in which they lived thus perpetuating the ongoing evolution from wolf to dog. Behavioral differences – between wolf and dog As a result, of continued domestication it seems dogs have undergone considerable behavioral changes furthering them farther away from their now canine cousin the wolf.

The domestic dog has transformed into a more docile and affectionate animal than the wolf. According to Lindsay, “…dogs have lost the lupine carnivorous drive and predatory behavior exhibited by wild canids.” Even though dogs prefer meat, their diets today can consist of a vast variety of foods, unlike what their “ancestral progenitors” may have eaten (Lindsay, 2000). Other notable differences are that dogs “tend to mature physically and sexually much more readily than wolves…dogs become sexually mature around 7 and 10 months” and “wolves reach sexual maturity at approximately 22 months.” Additionally, “…dogs will readily mate with multiple partners, have biannual breeding cycles, and male dogs are fertile year round.” Wolves tend to be more “selective and monogamous,” having annual breeding cycles and at times other than during the breeding cycle the males testes atrophy “rendering the wolf infertile” (Lindsay, 2000). Some distinct differences are the dog’s ability to alarm bark and scent mark. Wolves perform these behaviors, but less frequently.

It is important to note not all-domestic dogs bark, Lindsay suggests the “…tendency to bark may be socially facilitated or learned.” He says, “Coppinger and Feinstein have disputed the functional and communicative value of the dogs barking behavior” and Lindsay says they have argued “…that barking behavior is poorly directed, excessively ambiguous, ‘indecisive’ – even meaningless.” He said, “…they conclude that the dog’s increased tendency to bark is an inadvertent symptom of domestication…rather than a genetically selected tendency” (Lindsay, 2000). The dog’s excessive need to mark by urinary scent distinguishes them from wolves. This appears to be an excessive way to communicate and the exact cause is unknown. Some scientist have speculated it may serve to communicate territory, however according to Lindsay, “Scott (1967) argued that canine scent marking does not serve a territorial function, but rather functions more or less to communicate that the dog has been recently in the area” (Lindsay, 2000). Other behavioral differences include the “…display of aggressive behavioral patterns” between the species.

It has been noted that wolves “reaching sexual and social maturity, tend to compete much more aggressively and earnestly for social status.” Lindsay says, “fighting styles…differ significantly” noting that dogs “…tend to limit their attacks to the head, neck, and shoulder” and wolves tend to make better use of “body blocks…attacking extremities” rendering the opponent into a more vulnerable position (Lindsay, 2000). A truly unique quality retained by the domestic dog is the typical dog’s willingness and tolerance to accept strangers. Wolves tend not to accept strangers even among their own pack. The typical wolf would be wary of human presence and tend to have a low threshold for flight. Today environmental pressure from humans continues to make it difficult for wolves to thrive in many regions of the world.

According to Lindsay, an important influence of domestication is the “attenuation of predatory instincts.” He says, “wolves possess a set of innate predatory behavior patterns that are readily evoked by an adequate stimulus…presented with a prey animal, wolves respond in a species-typical manner by emitting an appropriate series of behavior sequences.” The sequence of behaviors may include crouching, stalking, worrying, charging, pouncing, biting, and shaking. Presented with “…the same prey stimulus, dogs may do little more than play or tease the target animal” (Lindsay, 2000). The question of intelligence between the species seems to separate some scientist, with some insisting wolves are more intelligent. According to these scientists, “…wolves must work for their living” and have considerable “…variations in proportional brain sizes.” Lindsay concludes, “…such speculation is fascinating” however he suggests, “it may be more productive to study relative intelligence among canids by comparing their performance under controlled conditions and discuss intelligence in terms of quantifiable learning skills and problem-solving abilities” (Lindsay, 2000).

One of the more endearing qualities of dogs is the tendency to retain puppy like characteristics well into adult life, most likely an adaptation of domestication. According to Lindsay, “…several behavioral changes can be detected in the direction of youthfulness.” He says, “…domestic dogs appear in many respects to act like 4- to 6- month-old wolf puppies.” The process of retaining these childlike qualities is known as neotony (Lindsay, 2000). Lastly, wolves tend to form social bonds with humans in the absence of adult conspecifics and fear. On the other hand, dogs form attachments to humans easily, actually preferring human contact rather than conspecifics when given a choice. The reduced flight tendency resulting in tameness and acquired through domestication has aided in creating a strong motivation to seek social contact with humans. The dog continued to evolve from the early protodog, eventually trained to herd, guard livestock and assist in hunting. Most recently, deliberate breeding processes selecting various desirable traits has given us over 400 recognized breeds of dogs. This diversity is unknown in any other species and truly makes the dog unique.

Today, dogs serve us in many different functions and we continue to find more ways to utilize them every day. References

Question: How many species of domestic dog are found today?
Answer: One