Néolithique | EPFL Graph Search

vignette|Un village néolithique sur palafittes reconstitué, sur le lac de Constance, près de Unteruhldingen, en Allemagne. Le Néolithique (parfois nommé « âge de la pierre polie »), qui succède au Mésolithique, est une période préhistorique marquée par de profondes mutations techniques et sociales, liées à l’adoption par les groupes humains d’un modèle de subsistance fondé sur l’agriculture et l’élevage, et impliquant le plus souvent une sédentarisation. Les principales innovations techniques sont la généralisation de l'outillage en pierre polie, la poterie, le tissage, ainsi que le développement de l'architecture. Selon les aires géographiques considérées, ces importantes mutations sont relativement rapides et certains auteurs ont pu parler de « révolution néolithique ». La néolithisation est toutefois un phénomène progressif, survenu à des dates différentes selon les régions. Le Néolithique débute au Proche-Orient au millénaire av. J.-C. dans le Croissant fertile, et atteint la Gr

Genome-wide SNP profiling of worldwide goat populations reveals strong partitioning of diversity and highlights post-domestication migration routes

Stéphane Joost, Estelle Rochat, Elia Vajana

Background: Goat populations that are characterized within the AdaptMap project cover a large part of the worldwide distribution of this species and provide the opportunity to assess their diversity at a global scale. We analysed genome-wide 50K single nucleotide polymorphism (SNP) data from 144 populations to describe the global patterns of molecular variation, compare them to those observed in other livestock species, and identify the drivers that led to the current distribution of goats. Results: A high degree of genetic variability exists among the goat populations studied. Our results highlight a strong partitioning of molecular diversity between and within continents. Three major gene pools correspond to goats from Europe, Africa and West Asia. Dissection of sub-structures disclosed regional gene pools, which reflect the main post-domestication migration routes. We also identified several exchanges, mainly in African populations, and which often involve admixed and cosmopolitan breeds. Extensive gene flow has taken place within specific areas (e.g., south Europe, Morocco and Mali-Burkina Faso-Nigeria), whereas elsewhere isolation due to geographical barriers (e.g., seas or mountains) or human management has decreased local gene flows. Conclusions: After domestication in the Fertile Crescent in the early Neolithic era (ca. 12,000 YBP), domestic goats that already carried differentiated gene pools spread to Europe, Africa and Asia. The spread of these populations determined the major genomic background of the continental populations, which currently have a more marked subdivision than that observed in other ruminant livestock species. Subsequently, further diversification occurred at the regional level due to geographical and reproductive isolation, which was accompanied by additional migrations and/or importations, the traces of which are still detectable today. The effects of breed formation were clearly detected, particularly in Central and North Europe. Overall, our results highlight a remarkable diversity that occurs at the global scale and is locally partitioned and often affected by introgression from cosmopolitan breeds. These findings support the importance of long-term preservation of goat diversity, and provide a useful framework for investigating adaptive introgression, directing genetic improvement and choosing breeding targets.

BMC2018

L'habitant et la cohabitation dans les modèles de l'espace habité

André Ourednik

The notion of habiter (inhabiting in both a transitive and intransitive sense), developed in the course of the second half of the 20th century, made it possible to place the human individual in the center of spatial theories. Of phenomenological inspiration, this notion has nevertheless contributed to widen the gap between on side, a quantitative geography oriented towards at spatial statistics and at mathematical models of the territory and, on the other side, a geography of spatial existence, seeking to understand the geographical space as a world lived by individuals. The aim of this thesis is to ill this gap by articulating both approaches in a comprehensive understanding of the inhabited space in general and of the Swiss territory in particular. The latter serves as the empirical context of the author's investigations. The thesis consists in three parts: a purely theoretical part, founded in an interdisciplinary literature and in concrete examples serving to illustrate the central notions, a first methodological and empirical part, dedicated to the synthesis and the analysis of Swiss statistical data, a second methodological and empirical part, dedicated to the construction of dynamic models of the inhabited space. The aim of the theoretical part is to clarify three central notions: the inhabiting individual, the formal model and the inhabited space. The concurrent aim is to assess the possibility to quantify cohabitation and to study it by the means of formal dynamic models. A particular attention is attached to the role of these models as pragmatic and existential operators of the habiter of individuals and of the cohabitation of communities. In both methodological/empirical parts, the theoretical conclusions of the first part are applied in the construction of renewed formal models of the contemporary Swiss inhabited space: Firstly, the author adapts the method of population measurement in order to reflect characteristics of inhabiting individuals which have been identified in the theoretical part but that are traditionally not accounted for in such measurements: namely individual mobility and "polytopicity". The result of this approach is a new synthetic image of the population distribution in the inhabited space. In other words, the author proposes a method that allows bringing the diachronic dimension of the Swiss territory on a sheet of paper. While the time-scales of habiter taken into account in the first methodological part are of the order of a day to a month, the second part is dedicated to larger time-scales of residential mobility. This stance allows the author to propose a way in which to model space both as objet and as a constraint of individual intentionality. In this approach the author leans on existing multi-agent models, while providing these with a renewed epistemological foundation, conceived in the perspective of an articulation with phenomenological approaches of the inhabited space. Three models have been constructed in that scope, each examining a different degree of individual acting freedom. The first model studies the structuring of a urban network in a highly constraining environment particular to first Neolithic urban communities. The second model examines retroaction phenomena induced by the deployment of individual actions in the environment and shows the potential divergence between the rationality behind these actions and their actual results. The third model insists on the role of individual actors by showing the impact of their interiorized models of cohabitation on the structure of the urban space; furthermore, it studies the leeway of public policies to inflect thus emerging tendencies. Taken as a whole, this thesis leads to the construction of a plurality of articulated models of the territory. This articulate plurality allows for a commensuration of individual practices and for a comparison of places and spaces, without renouncing to the phenomenological project of an understanding of the modeled realities as emergent and subject to an ongoing process of ontological transformation. Besides its general theoretical outreach, the statistical model reveals a highly more hierarchized Swiss urban network then perceived in preceding models, as well as the demographic importance of some still underestimated places (notably touristic destinations). As to the multi-inhabitant models, these reveal the great impact of individual expectations and expectation-lead actions on the structure of a territory, thus calling for new strategies in public policies towards a sustainable urban planning.

EPFL2010

L'habitant et la cohabitation dans les modèles de l'espace habité

André Ourednik

EPFL2010

Genome-wide SNP profiling of worldwide goat populations reveals strong partitioning of diversity and highlights post-domestication migration routes

Stéphane Joost, Estelle Rochat, Elia Vajana

BMC2018