"Thank you very much for creating such a wonderful, outstanding script. In my performance there were at least 52 students. They performed twice daily for four days. We only had one class signed up for the first performance. When word got around of the incredible job these students were doing, we ended up accommodating three classes in a classroom. The kids did a phenomenal job! The comments from parents and teachers were all positive and uplifting. We even had part-time teachers take leave so they could bring their young ones. Some of the parents came twice. The wonders of this play has reached other schools. Request for your products is on the rise. And the transformation of one of my students from an introvert to a dashing, expressive actor made me a believer that kids learn or get inspired through different learning modalities (he was the wolf). Thank you very much."
Genetic studies indicate that the grey wolf is the closest living relative of the dog.[5][16] Attempting to reconstruct the dog's lineage through the phylogenetic analysis of DNA sequences from modern dogs and wolves has given conflicting results for several reasons. Firstly, studies indicate that an extinct Late Pleistocene wolf is the nearest common ancestor to the dog, with modern wolves not being the dog's direct ancestor. Secondly, the genetic divergence (split) between the dog's ancestor and modern wolves occurred over a short period of time, so that the time of the divergence is difficult to date (referred to as incomplete lineage sorting). This is complicated further by the cross-breeding that has occurred between dogs and wolves since domestication (referred to as post-domestication gene flow). Finally, there have been only tens of thousands of generations of dogs since domestication, so that the number of mutations between the dog and the wolf are few and this makes the timing of domestication difficult to date.[5]
Wolf Down Stray From The Path Mp3
An apex predator 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 upheaval associated with the close of the Late Pleistocene, one type of wolf population rose to become today's apex predator and another joined with humans to become an apex consumer.[24] The domestication of this lineage ensured its evolutionary success through its expansion into a new ecological niche.[19]
For a long time scientists assumed that dogs evolved from the modern grey wolf. But a study published in 2014 concluded that this was incorrect, and that dogs are descended from an extinct type of wolf.[25][26]
In 2020, a genomic study of Eurasian wolves found that they and the dog share a common ancestor which is dated to 36,000 YBP. This finding supports the theory that all modern wolves descend from a single population which expanded after the Last Glacial Maximum and replaced other wolf populations that were adapted to different climatic conditions, and the finding of dog-like fossils dated over 30,000 YBP.[30]
Another DNA study indicated that dogs originated in the Middle East due to the sharing of DNA between dogs and Middle Eastern grey wolves.[40] In 2011, a study found this indication to be incorrect because there had been hybridization between dogs and Middle Eastern grey wolves.[41][33] In 2012, a study indicated that dogs derived from wolves originating in the Middle East and Europe and this was consistent with the archaeological record.[42] In 2014, a genomic study found that no modern wolf from any region was any more genetically closer to the dog than any other, implying that the dog's ancestor was extinct.[41]
In 2013, a study looked at the well-preserved skull and left mandible of a dog-like canid that was excavated from Razboinichya Cave in the Altai Mountains of southern Siberia.[45] It was dated to 33,300 YBP, which predates the oldest evidence from Western Europe and the Near East[43] The mDNA analysis found it to be more closely related to dogs than wolves.[45] Later in 2013, another study found that the canid could not be classified as a dog nor wolf because it fell between both.[20] In 2017, evolutionary biologists reviewed all of the evidence available on dog divergence and supported the specimens from the Altai mountains as being those of dogs from a lineage that is now extinct, and that was derived from a population of small wolves that is also now extinct.[5]
In 2013, a study sequenced the complete and partial mitochondrial genomes of 18 fossil canids from the Old and New Worlds whose dates range from 1,000 to 36,000 YBP, and compared these with the complete mitochondrial genome sequences from modern wolves and dogs. Clade A included 64% of the modern dogs sampled, and these are a sister group to a clade containing three fossil pre-Columbian New World dogs dated between 1,000 and 8,500 YBP. This finding supports the hypothesis that pre-Columbian New World dogs share ancestry with modern dogs and that they likely arrived with the first humans to the New World. Together, clade A and the pre-Columbian fossil dogs were the sister group to a 14,500 YBP wolf found in the Kessleroch cave near Thayngen in the canton of Schaffhausen, Switzerland, with a most recent common ancestor estimated to 32,100 YBP.[20]
One review considered why the domestication of the wolf occurred so late and at such high latitudes, when humans were living alongside wolves in the Middle East for the past 75,000 years. The proposal is that domestication was a cultural innovation caused through a long and stressful event, which was climate change. Domestication may have happened during one of the five cold Heinrich events that occurred after the arrival of humans in West Europe 37,000, 29,000, 23,000, 16,500, and 12,000 YBP. The theory is that the extreme cold during one of these events caused humans to either shift their location, adapt through a breakdown in their culture and change of their beliefs, or adopt innovative approaches. The adoption of the large wolf/dog was an adaptation to this hostile environment.[50]
More recent research analysing the genomes of 72 ancient wolves, specimens from Europe, Siberia and North America spanning the past 100,000 years has confirmed that both early and modern dogs are more similar genetically to ancient wolves from Asia than from Europe. This suggests that domestication occurred in the East. The research also found evidence that dogs have a dual ancestry, meaning that two separate populations of wolves contributed DNA to dogs. Early dogs from northeastern Europe, Siberia and the Americas appear to have a single, shared origin from the eastern source. But early dogs from the Middle East, Africa and southern Europe appear to have some ancestry from another source related to wolves in the Middle East, in addition to the eastern source. It is possible that wolves underwent domestication more than once, with different populations then mixing together. Or, that domestication happened once only, and that dual ancestry is related to early dogs then mixing with wild wolves. The research also demonstrated how wolf DNA changed during the 30,000 generations that were represented in their 100,000-year timeline. This identified the effects of natural selection as particular genes spread within wolf populations. One gene variant, over a period of around 10,000 years, went from being very rare to being present in every wolf, and it is still present in all wolves and dogs today. The variant affects a gene, IFT88, which is involved in the development of bones in the skull and jaw. It is possible that the spread of this variant could have been driven by a change in the types of prey available during the Ice Age, giving an advantage to wolves with a certain head shape. "This is the first time scientists have directly tracked natural selection in a large animal [the wolf] over a time-scale of 100,000 years, seeing evolution play out in real time rather than trying to reconstruct it from DNA today," said study senior author Pontus Skoglund.[54]
The questions of when and where dogs were first domesticated have taxed geneticists and archaeologists for decades.[11] 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.[16] There is clear evidence that dogs were derived from grey wolves during the initial phases of domestication. 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 consensus regarding either the timing or location(s) of domestication, the number of wolf populations that were involved, or the long-term effects domestication has had on the dog's genome.[16]
Around 10,000 YBP agriculture was developed resulting in a sedentary lifestyle, along with phenotype divergence of the dog from its wolf ancestors, including variance in size.[5] Two population bottlenecks have occurred to the dog lineage, one due to the initial domestication and one due to the formation of dog breeds.[5][16]
The dog is a classic example of a domestic animal that likely traveled a commensal pathway into domestication.[2][38] 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.[38] It may have been inevitable that the first domesticated animal came from the order of carnivores as these are less afraid when approaching other species. Within the carnivores, the first domesticated animal would need to exist without an all-meat diet, possess a running and hunting ability to provide its own food, and be of a controllable size to coexist with humans, indicating the family Canidae, and the right temperament[64] with wolves being among the most gregarious and cooperative animals on the planet.[65][66] 2ff7e9595c
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