Late hunter-gatherers and early farmers in Iberia: an ancient DNA and isotope perspective
The transition from foraging to farming is one of the most drastic shifts visible in the<br />archaeological record. In Europe, the so-called ‘Meso-Neolithic transition follows a<br />chronological gradient from the origin in the Near East to Western Europe, following two main<br />...
| Autores: | , , , |
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| Tipo de recurso: | tesis de maestría |
| Estado: | Versión publicada |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | Universidad de Zaragoza |
| Repositorio: | Zaguán. Repositorio Digital de la Universidad de Zaragoza |
| OAI Identifier: | oai:zaguan.unizar.es:108264 |
| Acceso en línea: | http://zaguan.unizar.es/record/108264 |
| Access Level: | acceso abierto |
| Palabra clave: | arquogia prehistoria genetica humana de poblaciones isotopos |
| Sumario: | The transition from foraging to farming is one of the most drastic shifts visible in the<br />archaeological record. In Europe, the so-called ‘Meso-Neolithic transition follows a<br />chronological gradient from the origin in the Near East to Western Europe, following two main<br />routes: the Danubian inland route and the Mediterranean route. In this sense, the Iberian<br />Peninsula, located in the southwestern part of Europe is a key region to study the transition<br />from foraging to farming in the most distant end of the expansion. Previous studies have pointed<br />out that the previous local hunter-gatherers were genetically very distinct from the newly<br />arriving farmers. Mitochondrial DNA analysis showed an almost complete replacement of the<br />hunter-gatherer mitochondrial haplogroups at the beginning of the Neolithic. Analysis of<br />autosomal genome-wide data confirms that most of the genetic ancestry of farmers is derived<br />directly from Anatolian Neolithic groups with a limited admixture of hunter-gatherer ancestry<br />along the routes of expansion.<br />In terms of subsistence, it is also possible to track a substantial change in the lifestyle of the<br />first Neolithic communities in comparison with previous hunter-gatherer groups. The new food<br />producing economy caused a decrease in dietary diversity. We observe a systematic<br />abandonment/negligence/disregard of marine resources albeit a persistence of hunting, and<br />usually combined with management of domestic livestock and crops. Farming also included a<br />variety of husbandry strategies, such as feeding animals with special fodder or human waste<br />products, the use of enclosures for animal keeping, transhumance and the use of natural<br />fertilizers on crops. The analysis of stable isotope analysis (carbon and nitrogen) in bone<br />collagen from faunal and human remains is the most common used technique to study the new<br />farming strategies as well as human diet. In addition, strontium isotopes, which are able to<br />provide insights about the provenance of individuals, can help to correlate dietary shifts in<br />specific individuals, and are also useful to explore the demographic structure of a community.<br />The aim of this thesis is to study the impact of the Neolithic arrival to the Iberian Peninsula on<br />autochthonous hunter-gatherers and their lifestyle and the evolution of the following Neolithic<br />communities. Here, I applied the most advanced methods currently used in paleogenomic<br />research, such as Next Generation Sequencing (NGS) and the capture of 1240K informative<br />SNPs of the human genome. Thanks to these methods we have been able to recover genomewide<br />data from eleven individuals ranging from ~ 13000 cal BP to 5000 cal BP. Moreover, we<br />have produced more than 200 carbon (δ13C) and nitrogen (δ15N) isotopic collagen values,<br />increasing considerably the dataset available for the Iberian Peninsula at this period, and even<br />more so for the isotopic collagen data available on Early Neolithic fauna remains. In addition,<br />we have generated the first big published data set of more than 80 strontium values (87Sr/86Sr)<br />of human enamel and created a preliminary bioavailable strontium map of the Pre-Pyrenean<br />landscape with more than 100 samples.<br />The genetic results showed a unique genetic structure in Iberian HG, resulting from admixture<br />of individuals related to Goyet Q-2 (Magdalenians) and Villabruna (Western Hunter-Gatherers)<br />genetic clusters. This suggests a survival of two lineages of Late Pleistocene ancestry in<br />Holocene western Europe, in particular the Iberian Peninsula, whereas HG ancestry in most<br />other regions was largely replaced by Villabruna-like ancestry. Traces of the dual huntergatherer<br />lineages (Goyet Q-2 and Villabruna) were also found in Iberian Early Neolithic<br />individuals, arguing for admixture with local Iberian hunter-gatherers. Early Neolithic<br />individuals with higher amounts of Goyet Q-2 like ancestry were located in Southern Iberia,<br />possibly reflecting the previous hunter-gatherer structure in that territory. During Middle<br />Neolithic times this signal start to be more homogenized but the Iberian sites continued having<br />a higher Goyet-2-like ancestry.<br />The results of the stable isotope analysis suggest a higher importance of animal husbandry than<br />agriculture/crop farming/plant cultivation, although the domestic species studied did not show<br />a special feeding signal compared to the wild ones. Besides, the large data set available now for<br />humans from the Late Neolithic and the Chalcolithic period allows to test the presence of two<br />different eco-geographic regions with statistics significance in isotopic values. The use of<br />strontium isotopes with the radiocarbon dates has allowed us to distinguish different burial<br />phases despite a common terrestrial diet.<br /> |
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