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Evolutionary history of wild goat (Capra aegagrus) and the goat (C. hircus) based on the analysis of mitochondrial and nuclear DNA polymorphism: Implications for conservation and for the origin of the domestication

Abstract : The goat (Capra hircus) was one of the first domesticated ungulates in Fertile Crescent more than 10,000 years ago. For investigating the evolutionary history and domestication process of this species, we studied its present genetic diversity and that of its wild progenitor, the bezoar (Capra aegagrus). Initially, the study of 2430 individuals from all over the old world allowed us to characterize the genetic diversity of domestic goats. This study included 946 new individuals from regions poorly studied until now, mainly the Fertile Crescent. The analysis concerned the HVI segment of the control region of the mtDNA. This large-scale study allowed to establish a clear nomenclature of the goat maternal haplogroups and also to assess the pertinence of defining new haplogroups. We found a large genetic diversity that was mainly distributed among goat haplogroups within geographical areas. However, even with such a huge data set, it remains difficult to understand the domestication history by the genetic analysis of domestic goats on its own. Therefore, to fully understand the domestication process, we compared the polymorphism of 487 modern bezoars from 43 localities covering most of their distribution areas to that of the 2430 goats. Based on mtDNA data, we found that 308 bezoars were close relatives to the six goat mtDNA haplogroups. They showed a higher population growth rate than other bezoars. This data supports a new two-step large-scale domestication scenario for goats. After an early phase of sustainable management of wild herds by humans (pre-domestication phase), the effective domestication took place over a large area. This area included Eastern Anatolia, the whole Zagros, the Central Iranian Plateau and the North-Eastern of Iran where wilds close-to-domestics are still present. The combined analysis of mtDNA and nuclear DNA polymorphisms for bezoars and domestic goats, demonstrated that a large genetic diversity, corresponding to a large number of mtDNA haplotypes, was captured at the initial step of the effective domestication. The first domesticated goats were able to capture most of the genetic diversity of their wild ancestors and clearly, the goats do not fit the bottleneck domestication paradigm. This scenario is very different from previous models, which call for restricted domestication centres and population bottlenecks.
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https://tel.archives-ouvertes.fr/tel-00312922
Contributor : Saeid Naderi <>
Submitted on : Wednesday, August 27, 2008 - 12:13:55 AM
Last modification on : Friday, November 6, 2020 - 3:42:28 AM
Long-term archiving on: : Thursday, June 3, 2010 - 6:56:54 PM

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  • HAL Id : tel-00312922, version 1

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Saeid Naderi. Evolutionary history of wild goat (Capra aegagrus) and the goat (C. hircus) based on the analysis of mitochondrial and nuclear DNA polymorphism: Implications for conservation and for the origin of the domestication. Ecology, environment. Université Joseph-Fourier - Grenoble I, 2007. English. ⟨tel-00312922⟩

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