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Final Edits
https://en.wikipedia.org/wiki/Talk:Origin_of_the_domestic_dog#Addition_of_morphologies_in_the_domestic_dog

Addition of morphologies in the domestic dog[edit] This article talks about specialization of the different breeds of dogs bred for different jobs, but does not discuss the many different morphologies. For example, companion dogs have a wide variety in skull shape, where as working dogs have little variety, and wild dog species have almost no variation at all. [1]Snodgrass.370 (talk) 19:22, 17 November 2014 (UTC)

Domesitication[edit] The domestication of dog also brought about negative changes to the dog's DNA. Although many genetic mutations are now bred for, some have proved to be deleterious. The nature of positive assortative mating and possible positive selection at certain loci which may coincide with deleterious mutations caused nonsynonymous mutations to accumulate. Domestication also caused two major bottlenecks in the dog species. The first was during the original domestication of the dog and dealt with population changes and migration with humans. The second bottleneck was more recent, during the rise of breed creation. Human selection may alter the effectiveness of the purifying effects natural selection imposes on animals. The bottlenecks that have occurred only increased genetic drift and caused these deleterious mutations to be more prevalent. These mutations have given rise to a wide variety of genetic diseases. The second bottleneck especially may give reason as to why certain conditions seem to be breed specific among dogs, such as demyelination in German Shepherds. [2] Snodgrass.370 (talk) 19:04, 17 November 2014 (UTC)

Specialization[edit] The wide variety of specialization in dogs stems from the selection of dogs for their tamability. Selection for this one trait alone brought along a vast number of new morphological features. Selecting for a tame dog to breed changed the physiological features of that dog’s offspring, affecting the hormones and neurochemicals of the dogs. With domestication came variations in size, coat, color, behavior, and even reproductive cycles. Once these changes were present, it became easy for humans to breed dogs for their own personal preference. [3] Snodgrass.370 (talk) 19:04, 17 November 2014 (UTC)

Final Draft Starts Here
There are approximately 400 recognized breeds of dogs in the world today. With almost 37% of American households including a family canine, it is safe to say that the domestication of dog plays a major role in daily life, even if the evolutionary content is often overlooked. Every difference in coat, size, color, and personality was carefully chosen for by humans over centuries. What started out as a choice for a good hunting companion and protector has turned into an overwhelming amount of choices for another member of the family. Humans have succeeded in making dogs the most widely diverse species on the planet, and only required a fraction of the time that natural selection would take to do it. (Corner P & Manier J 2002) It is widely accepted that the dog originated in Asia some 10,000-15,000 years ago, with the ancestral species being the Grey Wolf, Canis lupus. The place and exact time are still under great debate. One 2009 study, looking at mitochondrial DNA, claims that the domesticated dog, Canis familiaris, arose less than 16,300 years ago near the Yangtze River in China. The study also shows that dog was created through the mating of several hundred domesticated wolves. (Mol. Biol. Evol. 2009) This date and location could point to a few different reasons for taming the wolves that resulted in domesticated dogs. This was the beginning of the rice culture in Asia. It could be that dogs were used as help for hunters and gatherers. Dogs could have also been a source of protection for the people of China. Furthermore, it could be hypothesized that the Chinese people used the dogs as a form of livestock, as dogs have been a food source in Asia more than any other place in the world. (Mol. Biol. Evol. 2009) As dogs became more and more a part of culture, people began the process of artificial selection. Dogs were first bred for their tamability. (Trut 1999) It is assumed that humans wanted a companion that could easily adapt to their home and lifestyle. Selection for this one trait alone brought along a vast number of new morphological features. Selecting for a tame dog to breed changed the physiological features of that dog’s offspring. It affected the hormones and neurochemicals of the dogs. With domestication came variations in size, coat, color, behavior, and even reproductive cycles. ( Trut 1999) Once these changes were present, it became easy for humans to breed dogs for their own personal preference. This explains why there is such a large variety of dogs seen today. A person in this day and age can find a dog that matches almost any preference that they may have, whether it be for personality, hair, level of physical activity, or all of the above and beyond. Morphologies in a dog span further than what is thought of when buying the next family pet. Skeletal morphology is what produces small and large breeds. There are differences in body size, leg length and width, and skull size. (Shearin & Ostrander 2010) Skull size changes throughout breeds, but even very different breeds of dog have more similar skulls than that of their wolf ancestors. Skull shape is very strict in wild species. Dogs selected for working skills seem to have a decent amount of consistency; however companion dogs have very diverse skull shape. ( Drake & Klingenberg 2010) This is to say that domestic dogs have much more variability than their wild relatives. Skull morphology also may help to prove that dogs are paedomorphic, that is they retain juvenile features in their adult form. (Morey 1994) Measured skulls of ancient dogs were found to greatly resemble juvenile wolf skulls, but look very different from adult wolf skulls. (Morey 1994) Selecting for tamability may have affected the reproductive cycle in such a way that dogs reached sexual maturity earlier, while other physical features lagged behind. A major feature of dogs is their coat. Today there are several varieties to choose from when it comes to the coat of a dog. Fur varies in color, texture, length, pattern, and curl. There are even hairless dogs and dogs that do not shed, to appease allergy sufferers. It has been discovered that only 3 genes contribute to over 95% of the variance is pattern, texture, curl, and length. Color and hairlessness are controlled by other genes. (Shearin & Ostrander 2010) Similar effects to the coats of foxes were found in a 40 year domestication study. The first physical attributes to change when selecting solely for tameness were coat color and pattern. (Trut 1999) Comparably, many other domesticated animals show variance in their coat. Animals such as sheep, goats, donkeys, and horses can exhibit curly or wavy hair much like a poodle. Domestication has also had a large effect on dog’s reproductive cycle. In wolves, social maturity and sexual maturity occur at the same time. This normally happens from 18-24 months of age. After domestication, dogs’ sexual maturity occurs anywhere from 6-9 months, but they are still reaching for social maturity until about 2 years of age. (Morey 1994) Dogs are, therefore, sexually mature for more of their lives than their wolf ancestors. Wolves are seasonal breeders. Males and females are only able to breed once a year, normally in the spring. Male dogs produce sperm year round, and female dogs normally have 2 estrous cycles a year. Dogs also, on average, have larger litters than wolves. (Morey 1994) After the initial changes caused by domestication itself, dogs seem to have been selected by humans to produce the most puppies they can in their lifetimes. This was probably due to the profit that could be made by selling puppies. Today there is a booming market for pure-bred and hybridized dogs. The more puppies that these dogs can produce, the more profit their owners are going to see from them. The major trait that sets dogs apart from their ancestors is their behavior, especially their social and emotional skills. Dogs are able to communicate with humans much easier than the wolf, and they have even outperformed primates on some tests of cognitive ability. Dog puppies have levels of social-cognitive skills that mirror those seen in human babies. (Mol. Biol. Evol. 2013) Their window of socialization is much larger than those of undomesticated animals. They begin bonding with humans as soon as they can see and hear, and their fear of the unknown does not begin until several weeks after that. (Trut 1999)A dogs social behavior does not fully mature until they are around 2 years of age. (Morley 1994) They are able to follow gestures and even human glances to find hidden food, a trait that is missing in even tamed wolves. (Mol. Biol. Evol. 2013) Although both wolves and dogs are capable of forming social groups, these groups are often very different. A dog has a household social group, human family and other household pets. A wolf’s social group is simply the other members of its pack. Wolves are often aggressive to members of their own pack and will utilize ritual behavior to assert dominance without injuring other members of the pack. Dogs have lost the need for this ritualized dominant and submissive display; therefore the displays have been much relaxed in their domestication. (Corner & Manier 2002) These advanced levels of social cognition illustrate that during artificial selection the canine brain was forced to evolve rapidly, giving way for domesticated behavior. This was further proved through a 2013 study looking at brain-expressed genes in dogs. (Mol. Biol. Evol. 2013) There have been many genetic mutations that have occurred in the domestication of the modern canine. Most of these mutations were bred for. Some, however, proved to be deleterious. There has been an increase of nonsynonymous mutations in the dog following domestication. There are factors that go along with domestication itself that cause these nonsynonymous mutations to add up and become deleterious. One is the nature positive assortative mating, choosing dogs with similar traits to breed. Another is positive selection at certain loci which may coincide with a deleterious mutation. Domestication caused two major bottlenecks in the population. The first was during the original domestication of the dog and dealt with population changes and migration with humans. The second bottleneck was more recent, during the rise of breed creation. Human selection may alter the effectiveness of the purifying effects natural selection imposes on animals. The bottlenecks that have occurred only increased genetic drift and caused these deleterious mutations to be more prevalent. These mutations have given rise to a wide variety of genetic diseases. (Mol. Biol. Evol. 2008) The second bottleneck especially may give reason as to why certain conditions seem to be breed specific among dogs, such as demyelination in German Shepherds. In conclusion, the evolution of the domesticated dog has had vast results. It has turned the dog into the most widely varied species on the planet. The 400 or so species of dogs show just how powerful artificial selection can really be. Dogs vary in almost every feature you could think of. They have different structures, colors, coats, behaviors, and genetic diseases. The most amazing thing about all of these genetic differences is that they all originate from the selection of just one trait. 16,300 years ago, humans began selecting dogs for tameness alone, and thereby gave us all of the differentiation that we are able to see today.

References Corner, P., & Manier, J. (2002, November 22). Scientist Give Dogs Their Day. Retrieved October 20, 2014, from http://www.hilltopanimalhospital.com/canine origins.htm Cruz, F., Vila, C., & Webster, M. (2008). The Legacy of Domestication: Accumulation of Deleterious Mutations in the Dog Genome. Mol. Biol. Evol., 25(11), 2331-2336. Retrieved September 12, 2014. Drake, A., & Klingenberg, C. (2010). Large-Scale Diversification of Skull Shape in Domestic Dogs: Disparity and Modularity. The American Naturalist, 175(3), 289-301. Retrieved October 20, 2014. Driscoll, C., & MacDonald, D. (2010). Journal of Biology. Top Dogs: Wolf Domestication and Wealth. Retrieved October 20, 2014, from http://www.biomedcentral.com/1741-7007/8/16/ Li, Yan, Bridgett M. VonHoldt, Andy Reynolds, Adam R. Boyko, Robert K. Wayne, Dong-Dong Wu, and Ya- Ping Zhang. "Artificial Selection on Brain-Expressed Genes during the Domestication of Dog." Molecular Biology and Evolution 30.8 (2013): 1867-876. Oxford Journals. Web. 12 Sept. 2014. . Lindblad-Toh, Kerstin, Claire M. Wade, Terjei S. Mikkelsen, and Et Al. "Genome Sequence, Comparitive Analysis and Haplotype Structure of the Domestic Dog." NATURE 438.8 (2005): 803-19. NATURE. Web. 12 Sept. 2014. 

Morey, D. (1994). The Early Evolution of the Domestic Dog. The American Scientist, 82, 336-347. Retrieved October 20, 2014.

Ostrander, E. (n.d.). Genetics and the Shape of Dogs. American Scientist. Retrieved October 20, 2014, from http;//www.americanscientist.org/issues/num2/genetics-and-the-shape-of-dogs/3 Pang, Jun-Feng, Cornelya Kluetsch, Xiao-Ju Zou, and Et Al. "MtDNA Data Indicate a Single Origin for Dogs South of Yangtze River, Less Than 16,300 Years Ago, from Numerous Wolves." Molecular Biology and Evolution 26.12 (2009): 2849-864. Oxford Journals. Web. 12 Sept. 2014. Shearin, A., & Ostrander, E. (2010). Canine Morphology: Hunting for Genes and Tracking Mutations. Biology. Retrieved October 28, 2014, from http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1000310 Trut, Lyudmila N. "Early Canid Domestication: The Farm-Fox Experiment: Foxes Bred for Tamability in a 40-year Experiment Exhibit Remarkable Transformation That Suggest an Interplay between Behavioral Genetics and Development." American Scientist 87.No. 2 (MARCH-APRIL 1999) (1999): 160-69. JSTOR. Web. 1 Jan. 2014. .

https://en.wikipedia.org/wiki/Origin_of_the_domestic_dog

(Suggestions) Addition to Specialization[edit] This section discusses what certain breeds of dogs are chosen for, but does not discuss the very origin of the dog's variability. In "The Farm Fox Experiment" (Lyudmila N. Trut 1999) foxes are domesticated in hopes of finding similar characteristics to those of the domesticated dog. They found many similar features that were caused simply by artificially selecting these foxes for tameness alone. These changes not only included behavioral characteristics, but also changes in size, coat color, reproductive cycles, etc. The experiment illustrated that the variability in dogs stemmed from humans selecting for tameness. This artificial selection caused changes in the dogs' entire genome, affecting hormones and other physiological systems. The process of selecting for behavior is what gave us the vast range of dog breeds we have today. Snodgrass.370 (talk) 06:08, 28 September 2014 (UTC)

Addition of deleterious mutations that came with domestication[edit] This article lacks mention of the deleterious mutations that stemmed from the domestication of the common dog. Severe bottlenecks during the domestication from the ancestral wolf and during breed creation in the past few hundred years caused an increase in deleterious mutations in the species. (Fernando Cruz 2008) Snodgrass.370 (talk) 06:07, 28 September 2014 (UTC)

Addition to DNA[edit] This article discusses the DNA evidence of dog descending from wolf, but fails to include any other DNA facts about the two species' differentiation. For example, the evolution of genes from the wolf DNA through the domestication of the dog; these genes evolved rapidly, giving the dog the brain-behavior characteristics that the wolf does not have. Some of these brain-behavior characteristics include tracking human glances and social-cognitive skills before any interaction with humans. (Artificial Selection on Brain-Expressed Genes During the Domestication of Dog 2013) Snodgrass.370 (talk) 06:08, 28 September 2014 (UTC)

(Edit&Citation) Specialization These specializations originated simply from human selection for tameness alone.

Trut, Lyudmila N. "Early Canid Domestication: The Farm-Fox Experiment: Foxes Bred for Tamability in a 40-year Experiment Exhibit Remarkable Transformation That Suggest an Interplay between Behavioral Genetics and Development." American Scientist 87.No. 2 (MARCH-APRIL 1999) (1999): 160-69. JSTOR. Web. 1 Jan. 2014. . Snodgrass.370 (talk) 06:02, 28 September 2014 (UTC)

My topic for the Wikipedia project is Artificial Selection in Dogs Li, Yan, Bridgett M. VonHoldt, Andy Reynolds, Adam R. Boyko, Robert K. Wayne, Dong-Dong Wu, and Ya- Ping Zhang. "Artificial Selection on Brain-Expressed Genes during the Domestication of Dog." Molecular Biology and Evolution 30.8 (2013): 1867-876. Oxford Journals. Web. 12 Sept. 2014. . This journal article illustrates that the social-cognitive skills in dogs are actually a trait derived through artificial selection. The article hypothesizes that these traits can be produced through changes in developmental regulation. This hypothesis is found to be true, stating that these traits come more from gene regulation than from the genes themselves. This article compares gene expression from ancient dogs and wolves to confirm their hypothesis.

Lindblad-Toh, Kerstin, Claire M. Wade, Terjei S. Mikkelsen, and Et Al. "Genome Sequence, Comparitive Analysis and Haplotype Structure of the Domestic Dog." NATURE 438.8 (2005): 803-19. NATURE. Web. 12 Sept. 2014. . This article explores the differences in genomes among different species of dogs. It compares a dog’s genes to orthologs of similar genes in other mammals to define the location of a dog’s genes of interest. It then further compares different dog breed’s genomes to discover why there is such a high level of genetic diversity among these breeds. It identifies genes that could be responsible for different traits or diseases, and explores their significance.

Pang, Jun-Feng, Cornelya Kluetsch, Xiao-Ju Zou, and Et Al. "MtDNA Data Indicate a Single Origin for Dogs South of Yangtze River, Less Than 16,300 Years Ago, from Numerous Wolves." Molecular Biology and Evolution 26.12 (2009): 2849-864. Oxford Journals. Web. 12 Sept. 2014. . The researchers of this article set out to pinpoint the origin of the first dog derived from the wolf. They analyzed the mitochondrial genome of 169 dogs to look at geographical diversity. They not only discovered the origin of the dog, but also were able to look at the human culture at that time. The dog originated in southern China 16,300 years ago, along with the origin of the rice culture.

Skoglund, Pontus, Anders Gotherstrom, and Mattias Jakobsson. "Estimation of Population Divergence Times from Non-Overlapping Genomic Sequences: Examples from Dogs and Wolves." Molecular Biology and Evolution 28.4 (2011): 1505-517. Oxford Journals. Web. 12 Sept. 2014. . This article also looks at the origin of the dog. These researchers use DNA sequencing to look at how long each dog took to derive from its wolf ancestor. They use ancient dogs and wolves from India, China, Spain, and Alaska to show how long it took for them to differentiate into their new species. This article also illustrates how modern dog breeds have more similar genomes to each other than to their ancient ancestors. Furthermore, the researchers conclude that human interference in domesticating these animals could have happened even before agricultural development.

Trut, Lyudmila N. "Early Canid Domestication: The Farm-Fox Experiment: Foxes Bred for Tamability in a 40-year Experiment Exhibit Remarkable Transformation That Suggest an Interplay between Behavioral Genetics and Development." American Scientist 87.No. 2 (MARCH-APRIL 1999) (1999): 160-69. JSTOR. Web. 1 Jan. 2014. . This 40 yearlong study of the domestication of foxes helps to show what the domestication of dogs may have been like. It compares the taming of foxes to the taming of wild dogs in many different ways and finds that the process of domestication is very similar, even down to changes in coat, color, size, and reproduction cycle. The article states that selecting an animal for tameness means selecting for a change in hormones and neurochemicals, which brings about massive effects on the animal’s development.