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5141410
Origin of the domestic dog
The study indicates that the western Eurasian wolf and dog populations genetically diverged 20,000-60,000 YBP. Immediately after this divergence, the dog population outnumbered the wolf population, and later the dog population underwent a population reduction to be much lower.
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Origin of the domestic dog
Section::::Divergence from wolves.:Place of genetic divergence.:Two origins disputed.
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Origin of the domestic dog
In 2017, a study compared the nuclear genome sequences of three ancient dog specimens from Germany and Ireland with sequences from over 5,000 dogs and wolves. These Neolithic dog specimens included a dog sample from the Early Neolithic site in Herxheim, Germany dated 7,000 YBP, one from the Late Neolithic site of Kirsc...
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Origin of the domestic dog
A 2018 study of mDNA sequences shows that the pre-Neolithic dogs of Europe all fell under haplogroup C. The Neolithic and Post-Neolithic dogs from Southeastern Europe that are associated with farmers fell under haplogroup D. In Western and Northern Europe, haplogroup D became diluted into the native dog population. Thi...
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Origin of the domestic dog
Section::::Divergence from wolves.:Morphological divergence.
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Origin of the domestic dog
The questions of when and where dogs were first domesticated have taxed geneticists and archaeologists for decades. Identifying the earliest dogs is difficult because the key morphological characters that are used by zooarchaeologists to differentiate domestic dogs from their wild wolf ancestors (size and position of t...
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Origin of the domestic dog
Section::::Divergence from wolves.:Morphological divergence.:Early dog specimens.
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Origin of the domestic dog
There are a number of recently discovered specimens which are proposed as being Paleolithic dogs, however their taxonomy is debated. These have been found in either Europe or Siberia and date 40,000-17,000 YBP. They include Hohle Fels in Germany, Goyet Caves in Belgium, Predmosti in the Czech Republic, and four sites i...
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Origin of the domestic dog
There are also a number of later proposed Paleolithic dogs whose taxonomy has not been confirmed. These include a number of specimens from Germany (Kniegrotte, Oelknitz, Teufelsbrucke), Switzerland (Monruz, Kesslerloch, Champre-veyres-Hauterive), and Ukraine (Mezin, Mezhirich). A set of specimens dating 15,000-13,500 Y...
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5141410
Origin of the domestic dog
Possible dog domestication between 40,000-15,000 years ago is not clear due to the debate over what the Paleolithic dog specimens represent. This is due to the flexibility of genus "Canis" morphology, and the close morphological similarities between "Canis lupus" and "Canis familiaris". It is also due to the scarcity o...
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Origin of the domestic dog
A domestication study looked at the reasons why the archeological record that is based on the dating of fossil remains often differed from the genetic record contained within the cells of living species. The study concluded that our inability to date domestication is because domestication is a continuum and there is no...
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Origin of the domestic dog
Section::::Dog domestication.
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Origin of the domestic dog
The earlier association of dogs with humans may have allowed dogs to have a profound influence on the course of early human history and the development of civilization. However, the timing, geographic locations, and ecological conditions that led to dog domestication are not agreed.
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Origin of the domestic dog
There is clear evidence that dogs were derived from gray wolves during the initial phases of domestication and that no other canine species was involved. The wolf population(s) that were involved are likely to be extinct. Despite numerous genetic studies of both modern dogs and ancient dog remains, there is no firm con...
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Origin of the domestic dog
Genetic studies suggest a domestication process commencing over 25,000 YBP, in one or several wolf populations in either Europe, the high Arctic, or eastern Asia. The remains of large carcasses left by human hunter-gatherers may have led some wolves into entering a migratory relationship with humans. This could have le...
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Origin of the domestic dog
Genetic studies support two population bottlenecks having occurred to the dog lineage, one due to the initial domestication and one due to the formation of dog breeds.
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Origin of the domestic dog
Section::::Dog domestication.:Time of domestication.
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Origin of the domestic dog
An apex predator is a predator that sits on the top trophic level of the food chain, while a mesopredator sits further down the food chain and is dependent on smaller animals. Towards the end of the Pleistocene era, most of today's apex predators were mesopredators and this included the wolf. During the ecological uphe...
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Origin of the domestic dog
In August 2015, a study undertook an analysis of the complete mitogenome sequences of 555 modern and ancient dogs. The sequences showed an increase in the population size approximately 23,500 YBP, which broadly coincides with the proposed separation of the ancestors of dogs and present-day wolves before the Last Glacia...
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Origin of the domestic dog
Section::::Dog domestication.:Socialization.
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Origin of the domestic dog
Humans and wolves both exist in complex social groups. How humans and wolves got together remains unknown. One view holds that domestication as a process that is difficult to define. The term was developed by anthropologists with a human-centric view in which humans took wild animals (ungulates) and bred them to be "do...
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Origin of the domestic dog
Section::::Dog domestication.:Commensal pathway.
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Origin of the domestic dog
Animal domestication is a coevolutionary process in which a population responds to selective pressure while adapting to a novel niche that included another species with evolving behaviors.
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Origin of the domestic dog
The dog is a classic example of a domestic animal that likely traveled a commensal pathway into domestication. The dog was the first domesticant, and was domesticated and widely established across Eurasia before the end of the Pleistocene, well before cultivation or the domestication of other animals. It may have been ...
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Origin of the domestic dog
Ancient DNA supports the hypothesis that dog domestication preceded the emergence of agriculture and was initiated close to the Last Glacial Maximum 27,000 YBP when hunter-gatherers preyed on megafauna, and when proto-dogs might have taken advantage of carcasses left on site by early hunters, assisted in the capture of...
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Origin of the domestic dog
A maternal mitochondrial, paternal Y chromosome, and microsatellite assessment of two wolf populations in North America and combined with satellite telemetry data revealed significant genetic and morphological differences between one population that migrated with and preyed upon caribou, and another territorial ecotype...
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Origin of the domestic dog
Even today, the wolves on Ellesmere Island do not fear humans, which is thought to be due to them seeing humans so little, and they will approach humans cautiously, curiously and closely.
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Origin of the domestic dog
Section::::Dog domestication.:Post-domestication gene flow.
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Origin of the domestic dog
Since domestication, dogs have traveled alongside humans across most of the planet, often hybridizing
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Origin of the domestic dog
with local wild canids. This has resulted in complex patterns of ancient and recent admixture among both the wild and the domestic canids.
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Origin of the domestic dog
Some studies have found greater diversity in the genetic markers of dogs from East and Central Asia compared to Europe and have concluded that dogs originated from these regions, despite no archaeological evidence to support the conclusions. One reason for these discrepancies is the sustained admixture between differen...
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Origin of the domestic dog
Section::::Dog domestication.:Post-domestication gene flow.:Dog-Wolf admixture.
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Origin of the domestic dog
There is evidence of admixture between dog and regional wolf populations, except on the Tibetan Plateau and in the New World wolves. This admixture has occurred throughout history and as dogs expanded across the landscape. There are some dog populations that show recent admixture with wolves.
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Origin of the domestic dog
Phylogenetic analysis shows that modern dog mDNA haplotypes resolve into four monophyletic clades with strong statistical support, and these have been designated by researchers as clades A-D. Other studies that included a wider sample of specimens have reported two rare East Asian clades E-F with weaker statistical sup...
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Origin of the domestic dog
Haplogroup A: Includes 64-65% of dogs. Haplotypes of subclades a2–a6 are derived from post-domestication wolf–dog hybridization.
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Origin of the domestic dog
Haplogroup B: Includes 22-23% of dogs. haplotypes of subclade b2 are derived from post-domestication wolf–dog hybridization.
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Origin of the domestic dog
Haplogroup C: Includes 10-12% of dogs.
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Origin of the domestic dog
Haplogroup D: Derived from post-domestication wolf–dog hybridization in subclade d1 (Scandinavia) and d2 (South-West Asia). The northern Scandinavian subclade d1 hybrid haplotypes originated 480-3,000 YBP and are found in all Sami-related breeds: Finnish Lapphund, Swedish Lapphund, Lapponian Herder, Jamthund, Norwegian...
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Origin of the domestic dog
Haplogroup E: Derived from post-domestication wolf–dog hybridization in East Asia, (rare distribution in South-East Asia, Korea and Japan).
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Origin of the domestic dog
Haplogroup F: Derived from post-domestication wolf–dog hybridization in Japan. A study of 600 dog specimens found only one dog whose sequence indicated hybridization with the extinct Japanese wolf.
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Origin of the domestic dog
It is not known whether this hybridization was the result of humans selecting for phenotypic traits from local wolf populations or the result of natural introgression as the dog expanded across Eurasia.
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Origin of the domestic dog
In 2018, a study found a small amount of dog ancestry in 62% of Eurasian wolf specimens looked at, that hybridization had occurred across a wide number of timescales and not just recently, however in contrast there was almost no admixture detected in the North American specimens. There was introgression of the male dog...
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Origin of the domestic dog
Section::::Dog domestication.:Post-domestication gene flow.:Taimyr wolf admixture.
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Origin of the domestic dog
In May 2015, a study compared the ancestry of the Taimyr-1 wolf lineage to that of dogs and gray wolves.
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Origin of the domestic dog
Comparison to the gray wolf lineage indicated that Taimyr-1 was basal to gray wolves from the Middle East, China, Europe and North America but shared a substantial amount of history with the present-day gray wolves after their divergence from the coyote. This implies that the ancestry of the majority of gray wolf popul...
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Origin of the domestic dog
A comparison of the ancestry of the Taimyr-1 lineage to the dog lineage indicated that some modern dog breeds have a closer association with either the gray wolf or Taimyr-1 due to admixture. The Saarloos wolfdog showed more association with the gray wolf, which is in agreement with the documented historical crossbreed...
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Origin of the domestic dog
An attempt to explore admixture between Taimyr-1 and gray wolves produced unreliable results.
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Origin of the domestic dog
As the Taimyr wolf had contributed to the genetic makeup of the Arctic breeds, a later study suggested that descendants of the Taimyr wolf survived until dogs were domesticated in Europe and arrived at high latitudes where they mixed with local wolves, and these both contributed to the modern Arctic breeds. Based on th...
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Origin of the domestic dog
Section::::Dog domestication.:Positive selection.
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Origin of the domestic dog
Charles Darwin recognized the small number of traits that made domestic species different from their wild ancestors. He was also the first to recognize the difference between conscious selective breeding in which humans directly select for desirable traits, and unconscious selection where traits evolve as a by-product ...
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Origin of the domestic dog
Although it is easy to assume that each of these traits was uniquely selected for by hunter-gatherers and early farmers, beginning in 1959 Dmitry Belyayev tested the reactions of silver foxes to a hand placed in their cage and selected the tamest, least aggressive individuals to breed. His hypothesis was that, by selec...
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Origin of the domestic dog
The genetic difference between domestic and wild populations can be framed within two considerations. The first distinguishes between domestication traits that are presumed to have been essential at the early stages of domestication, and improvement traits that have appeared since the split between wild and domestic po...
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Origin of the domestic dog
In 2010, a study identified 51 regions of the dog genome that were associated with phenotypic variation among breeds in 57 traits studied, which included body, cranial, dental, and long bone shape and size. There were 3 quantitative trait loci that explained most of the phenotypic variation. Indicators of recent select...
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Origin of the domestic dog
In 2015, a study looked at over 100 pig genome sequences to ascertain their process of domestication. A model that fitted the data included admixture with a now extinct ghost population of wild pigs during the Pleistocene. The study also found that despite back-crossing with wild pigs, the genomes of domestic pigs have...
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Origin of the domestic dog
In 2014, a whole genome study of the DNA differences between wolves and dogs found that dogs did not show a reduced fear response but did show greater synaptic plasticity. Synaptic plasticity is widely believed to be the cellular correlate of learning and memory, and this change may have altered the learning and memory...
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Origin of the domestic dog
Section::::Dog domestication.:Positive selection.:Behavior.
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Origin of the domestic dog
Unlike other domestic species which were primarily selected for production-related traits, dogs were initially selected for their behaviors. In 2016, a study found that there were only 11 fixed genes that showed variation between wolves and dogs. These gene variations were unlikely to have been the result of natural ev...
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Origin of the domestic dog
In 2018, a study identified 429 genes that differed between modern dogs and modern wolves. As the differences in these genes could also be found in ancient dog fossils, these were regarded as being the result of the initial domestication and not from recent breed formation. These genes are linked to neural crest and ce...
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Origin of the domestic dog
Section::::Dog domestication.:Positive selection.:Dietary adaption.
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Origin of the domestic dog
AMY2B (Alpha-Amylase 2B) is a gene that codes a protein that assists with the first step in the digestion of dietary starch and glycogen. An expansion of this gene in dogs would enable early dogs to exploit a starch-rich diet as they fed on refuse from agriculture. In a study in 2014, the data indicated that the wolves...
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Origin of the domestic dog
In 2016, a study of the dog genome compared to the wolf genome looked for genes that showed signs of having undergone positive selection. The study identified genes relating to brain function and behavior, and to lipid metabolism. This ability to process lipids indicates a dietary target of selection that was important...
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Origin of the domestic dog
Section::::Dog domestication.:Natural selection.
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Origin of the domestic dog
Dogs can infer the name of an object and have been shown to learn the names of over 1,000 objects. Dogs can follow the human pointing gesture; even nine-week-old puppies can follow a basic human pointing gesture without being taught. New Guinea singing dogs, a half-wild proto-dog endemic to the remote alpine regions of...
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Origin of the domestic dog
A dog's cranium is 15% smaller than an equally heavy wolf's, and the dog is less aggressive and more playful. Other species pairs show similar differences. Bonobos, like chimpanzees, are a close genetic cousin to humans, but unlike the chimpanzees, bonobos are not aggressive and do not participate in lethal inter-group...
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Origin of the domestic dog
Section::::Dog domestication.:Dog and human convergent evolution.
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Origin of the domestic dog
As a result of the domestication process there is also evidence of convergent evolution having occurred between dogs and humans. The history of the two is forever intertwined. Dogs suffer from the same diseases as humans, which include cancer, diabetes, heart disease, and neurological disorders. The underlying disease ...
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Origin of the domestic dog
Section::::Dog domestication.:Dog and human convergent evolution.:Parallel evolution.
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Origin of the domestic dog
There are patterns of genes which are related by their function and these patterns can be found in both dogs and humans. This fact can be used to study the coevolution of gene function. Dogs accompanied humans when they first migrated into new environments. Both dogs and humans have adapted to different environmental c...
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Origin of the domestic dog
In 2007, a study found that dog domestication was accompanied by selection at three genes with key roles in starch digestion: AMY2B, MGAMand SGLT1, and was a striking case of parallel evolution when coping with an increasingly starch-rich diet caused similar adaptive responses in dogs and humans.
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Origin of the domestic dog
Section::::Dog domestication.:Dog and human convergent evolution.:Behavioral evidence.
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Origin of the domestic dog
Convergent evolution is when distantly related species independently evolve similar solutions to the same problem. For example, fish, penguins and dolphins have each separately evolved flippers as a solution to the problem of moving through the water. What has been found between dogs and humans is something less freque...
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Origin of the domestic dog
The pointing gesture is a human-specific signal, is referential in its nature, and is a foundation building-block of human communication. Human infants acquire it weeks before the first spoken word. In 2009, a study compared the responses to a range of pointing gestures by dogs and human infants. The study showed littl...
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Origin of the domestic dog
Later studies support coevolution in that dogs can discriminate the emotional expressions of human faces, and that most people can tell from a bark whether a dog is alone, being approached by a stranger, playing, or being aggressive, and can tell from a growl how big the dog is.
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Origin of the domestic dog
In 2015, a study found that when dogs and their owners interact, extended eye contact (mutual gaze) increases oxytocin levels in both the dog and its owner. As oxytocin is known for its role in maternal bonding, it is considered likely that this effect has supported the coevolution of human-dog bonding. One observer ha...
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Origin of the domestic dog
Section::::Dog domestication.:Dog and human convergent evolution.:Human adoption of some wolf behaviors.
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Origin of the domestic dog
In 2002, a study proposed that immediate human ancestors and wolves may have domesticated each other through a strategic alliance that would change both respectively into humans and dogs. The effects of human psychology, hunting practices, territoriality and social behavior would have been profound. Early humans moved ...
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Origin of the domestic dog
In 2003, a study compared the behavior and ethics of chimpanzees, wolves and humans. Cooperation among humans' closest genetic relative is limited to occasional hunting episodes or the persecution of a competitor for personal advantage, which had to be tempered if humans were to become domesticated. The closest approxi...
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Origin of the domestic dog
On the mammoth steppe the wolf's ability to hunt in packs, to share risk fairly among pack members, and to cooperate moved them to the top of the food chain above lions, hyenas and bears. Some wolves followed the great reindeer herds, eliminating the unfit, the weaklings, the sick and the aged, and therefore improved t...
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Origin of the domestic dog
Section::::First dogs.
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Origin of the domestic dog
The dog was the first species and the only large carnivore to have been domesticated. Over the past 200 years, dogs have undergone rapid phenotypic change and were formed into today's modern dog breeds due to artificial selection imposed by humans. These breeds can vary in size and weight from a teacup poodle to a gian...
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Origin of the domestic dog
Section::::First dogs.:Bonn–Oberkassel dog.
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Origin of the domestic dog
In 1914, on the eve of the First World War, two human skeletons were discovered during basalt quarrying at Oberkassel, Bonn in Germany. With them were found a right mandible of a "wolf" and other animal bones. After the end of the First World War, in 1919 a full study was made of these remains. The mandible was recorde...
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Origin of the domestic dog
Later studies assigned more of the other animal bones to the dog until most of a skeleton could be assembled. The humans were a man aged 40 years and a woman aged 25 years. All three skeletal remains were found covered with large 20 cm thick basalt blocks and were sprayed with red hematite powder. The consensus is that...
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Origin of the domestic dog
Section::::First dogs.:First dogs as a hunting technology.
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Origin of the domestic dog
During the Upper Paleolithic (50,000-10,000 YBP), the increase in human population density, advances in blade and hunting technology, and climate change may have altered prey densities and made scavenging crucial to the survival of some wolf populations. Adaptations to scavenging such as tameness, small body size, and ...
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Origin of the domestic dog
Researchers have proposed that in the past a hunting partnership existed between humans and dogs that was the basis for dog domestication.
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Origin of the domestic dog
Petroglyph rock art dating to 8,000 YBP at the sites of Shuwaymis and Jubbah, in northwestern Saudi Arabia, depict large numbers of dogs participating in hunting scenes with some being controlled on leashes. The transition from the Late Pleistocene into the early Holocene was marked by climatic change from cold and dry...
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Origin of the domestic dog
Section::::First dogs.:Dogs enter North America from Siberia.
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Origin of the domestic dog
In North America, the earliest dog remains were found in Illinois and radiocarbon dating indicates 9,900 YBP. These include three isolated burials at the Koster Site near the lower Illinois River in Greene County, and one burial 35 km away at the Stilwell II site in Pike County. These dogs were medium-sized adults arou...
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Origin of the domestic dog
In 2018, a study compared sequences of North American dog fossils with Siberian dog fossils and modern dogs. The nearest relative to the North American fossils was a 9,000 YBP fossil discovered on Zhokhov Island, arctic north-eastern Siberia, which was connected to the mainland at that time. The study inferred from mDN...
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Origin of the domestic dog
Section::::First dogs.:First dog breeds developed in Siberia.
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Origin of the domestic dog
In 2017, a study showed that 9,000 YBP the domestic dog was present at what is now Zhokhov Island. The dogs were selectively bred as either sled dogs or as hunting dogs, which implies that a sled dog standard and a hunting dog standard existed at that time. The optimal maximum size for a sled dog is 20–25 kg based on t...
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Origin of the domestic dog
The study proposes that after having diverged from the common ancestor along with the grey wolf, the evolution of "Canis familiaris" proceeded in three stages. The first was natural selection based on feeding behavior within the ecological niche that had been formed through human activity. The second was artificial sel...
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Origin of the domestic dog
Section::::First dogs.:Dogs enter Japan.
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Origin of the domestic dog
In Japan, temperate deciduous forests rapidly spread onto the main island of Honshu and caused an adaption away from hunting megafauna (Naumann's elephant and Yabe's giant deer) to hunting the quicker sika deer and wild boar in dense forest. With this came a change in hunting technology, including a shift to smaller, t...
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Origin of the domestic dog
Hunting dogs make major contributions to forager societies and the ethnographic record shows them being given proper names, treated as family members, and considered separate to other types of dogs. This special treatment includes separate burials with markers and grave-goods, with those that were exceptional hunters o...
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Origin of the domestic dog
Intentional dog burials together with ungulate hunting is also found in other early Holocene deciduous forest forager societies in Europe and North America, indicating that across the Holarctic temperate zone hunting dogs were a widespread adaptation to forest ungulate hunting.
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