subota, 12. svibnja 2012.

New light on early caprine herding strategies from isotope analysis: a case study from Neolithic Anatolia


Abstract

The measurement of stable carbon (δ13C) and nitrogen (δ15N) isotopes of caprine bone collagen from the Neolithic sites of Çatalhöyük and Aşıklı Höyük in south-central Anatolia have allowed examination of exploitation and herding practices of sheep and goats. The isotope values from protodomestic caprines at Aşıklı Höyük suggests that these animals were consuming very similar foods to each other and were all confined to the same or similar environments with no access to C4 plants. At Çatalhöyük, the results show how the caprine management strategy develops from the strategy seen at Aşıklı Höyük into a more varied practice at an early stage as the site grows with an increasing dietary contribution obtained from C4 plants. No change in diet is isotopically discernible at Aşıklı Höyük. Interestingly, no distinction could be made between the diets of sheep and goats at either site. Therefore, such studies are a useful method of examining the development of early herding or management strategies of caprines in the Near East.



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Founder effect, drift, and adaptive change in domestic crop use in early Neolithic Europe


Abstract

We document and quantify a significant reduction in crop diversity in the early central European Neolithic using a large multi-site database of archaeobotantical remains we compiled from published Neolithic sites across southwest Asia and Europe. Two hypotheses are proposed to account for the observed changes: one which claims that the different environmental conditions of central Europe selected for a different set of crop choices and strategies than in use in southeast and Mediterranean Europe; and a null hypothesis that explains the change as a drift process associated with a small founding population that subsequently undergoes rapid expansion. Through an agent-based simulation model, we test the null hypothesis and demonstrate that the drop in diversity exceeds that predicted by a drift process. We conclude by re-evaluating the possible adaptive changes underlying crop use in early Neolithic Europe.



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Y chromosome genetic variation in the Italian peninsula is clinal and supports an admixture model for the Mesolithic–Neolithic encounter


Abstract

The Italian peninsula, given its geographical location in the middle of the Mediterranean basin, was involved in the process of the peopling of Europe since the very beginning, with first settlements dating to the Upper Paleolithic. Later on, the Neolithic revolution left clear evidence in the archeological record, with findings going back to 7000 B.C. We have investigated the demographic consequences of the agriculture revolution in this area by genotyping Y chromosome markers for almost 700 individuals from 12 different regions. Data analysis showed a non-random distribution of the observed genetic variation, with more than 70% of the Y chromosome diversity distributed along a North–South axis. While the Greek colonisation during classical time appears to have left no significant contribution, the results support a male demic diffusion model, even if population replacement was not complete and the degree of Neolithic admixture with Mesolithic inhabitants was different in different areas of Italy.










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Late glacial recolonization of Europe from Near Eastern refugia

 couple of quick comments on this important new paper:

  • It is important to confirm the hypotheses put forward with ancient DNA data. For example, haplogroup V is said to be traced to Paleolithic SW Europe, and yet it is lacking in ancient DNA data. Looking at Jean Manco's ancient Eurasian DNA compendium, I only find a very late Neolithic hunter-gatherer sample from Pitted Ware in Sweden (2,800-2,000BC); if J/T subclades had entered Europe prior to the Neolithic, their almost complete absence in ancient DNA data is puzzling.
  • Both this and the recent "Copernican" paper provide age estimates for the same nodes of the tree using the mutation rate of Soares et al. (2009). The estimaets of Pala et al. (2012) appear to be older by several thousand years than those of Behar et al. (2012) for different nodes. I don't know whether this is due to a different methodology or different dataset, but, in any case, it is a warning to avoid very close correlations between archaeological-geological events and age estimates.
UPDATE: A press release on the article.

The American Journal of Human Genetics, Volume 90, Issue 5, 915-924, 4 May 2012 doi:10.1016/j.ajhg.2012.04.003

Mitochondrial DNA Signals of Late Glacial Recolonization of Europe from Near Eastern Refugia 

Maria Pala et al. 

Human populations, along with those of many other species, are thought to have contracted into a number of refuge areas at the height of the last Ice Age. European populations are believed to be, to a large extent, the descendants of the inhabitants of these refugia, and some extant mtDNA lineages can be traced to refugia in Franco-Cantabria (haplogroups H1, H3, V, and U5b1), the Italian Peninsula (U5b3), and the East European Plain (U4 and U5a). Parts of the Near East, such as the Levant, were also continuously inhabited throughout the Last Glacial Maximum, but unlike western and eastern Europe, no archaeological or genetic evidence for Late Glacial expansions into Europe from the Near East has hitherto been discovered. Here we report, on the basis of an enlarged whole-genome mitochondrial database, that a substantial, perhaps predominant, signal from mitochondrial haplogroups J and T, previously thought to have spread primarily from the Near East into Europe with the Neolithic population, may in fact reflect dispersals during the Late Glacial period, ∼19–12 thousand years (ka) ago. 

Link

Horse domestication


New research indicates that domestic horses originated in the steppes of modern-day Ukraine, southwest Russia and west Kazakhstan, mixing with local wild stocks as they spread throughout Europe and Asia. The research was published today, 07 May, in the journal PNAS.

For several decades scientists puzzled over the origin of domesticated horses. Based on archaeological evidence, it had long been thought that horse domestication originated in the western part of the Eurasian Steppe (Ukraine, southwest Russia and west Kazakhstan); however, a single origin in a geographically restricted area appeared at odds with the large number of female lineages in the domestic horse gene pool, commonly thought to reflect multiple domestication "events" across a wide geographic area.

In order to solve the perplexing history of the domestic horse, scientists from the University of Cambridge used a genetic database of more than 300 horses sampled from across the Eurasian Steppe to run a number of different modelling scenarios.

Their research shows that the extinct wild ancestor of domestic horses, Equus ferus, expanded out of East Asia approximately 160,000 years ago. They were also able to demonstrate that Equus ferus was domesticated in the western Eurasian Steppe, and that herds were repeatedly restocked with wild horses as they spread across Eurasia.
ScienceNOW also covers the new research, and reports on a contrasting viewpoint: 
Not all researchers are convinced, however. Archaeologist Marsha Levine of the University of Cambridge thinks using modern genetic samples to retrace horses' evolution is a dead end. "There's been mixing of cultures and mixing of horses in this region for many thousands of years," she says. "And so when you're looking at any modern horse, you just don't know where it's from." 

Bringing together many kinds of evidence is what will ultimately answer the whens and wheres of horse domestication, Levine says. "What we need to be doing is using material from excavations, sequencing ancient genes, and combining that with what we know from archaeological evidence about how animals were used in the past."
I agree with the idea that ancient DNA will ultimately confirm/reject the model presented in the paper. Of course, it may be the case that the west Eurasian steppe was the place where horse domestication happened, but it is also the place where local horses may be descended from European, West Asian, and Central Asian breeds. I'll have to read the paper to see how the problem of possible admixture between western and eastern horse breeds on the steppe is accounted for in the paper. 

PNAS doi: 10.1073/pnas.1111122109 

Reconstructing the origin and spread of horse domestication in the Eurasian steppe 

Vera Warmuth et al. 

Despite decades of research across multiple disciplines, the early history of horse domestication remains poorly understood. On the basis of current evidence from archaeology, mitochondrial DNA, and Y-chromosomal sequencing, a number of different domestication scenarios have been proposed, ranging from the spread of domestic horses out of a restricted primary area of domestication to the domestication of numerous distinct wild horse populations. In this paper, we reconstruct both the population genetic structure of the extinct wild progenitor of domestic horses, Equus ferus, and the origin and spread of horse domestication in the Eurasian steppes by fitting a spatially explicit stepping-stone model to genotype data from >300 horses sampled across northern Eurasia. We find strong evidence for an expansion of E. ferus out of eastern Eurasia about 160 kya, likely reflecting the colonization of Eurasia by this species. Our best-fitting scenario further suggests that horse domestication originated in the western part of the Eurasian steppe and that domestic herds were repeatedly restocked with local wild horses as they spread out of this area. By showing that horse domestication was initiated in the western Eurasian steppe and that the spread of domestic herds across Eurasia involved extensive introgression from the wild, the scenario of horse domestication proposed here unites evidence from archaeology, mitochondrial DNA, and Y-chromosomal DNA. 


LINK

četvrtak, 10. svibnja 2012.

Agriculture arrived in Cyprus 10,600 years ago


PNAS doi: 10.1073/pnas.1201693109

First wave of cultivators spread to Cyprus at least 10,600 y ago

Jean-Denis Vigne et al.

Early Neolithic sedentary villagers started cultivating wild cereals in the Near East 11,500 y ago [Pre-Pottery Neolithic A (PPNA)]. Recent discoveries indicated that Cyprus was frequented by Late PPNA people, but the earliest evidence until now for both the use of cereals and Neolithic villages on the island dates to 10,400 y ago. Here we present the recent archaeological excavation at Klimonas, which demonstrates that established villagers were living on Cyprus between 11,100 and 10,600 y ago. Villagers had stone artifacts and buildings (including a remarkable 10-m diameter communal building) that were similar to those found on Late PPNA sites on the mainland. Cereals were introduced from the Levant, and meat was obtained by hunting the only ungulate living on the island, a small indigenous Cypriot wild boar. Cats and small domestic dogs were brought from the mainland. This colonization suggests well-developed maritime capabilities by the PPNA period, but also that migration from the mainland may have occurred shortly after the beginning of agriculture. 

LINK

ponedjeljak, 7. svibnja 2012.


 By the mid-8th millennium calBP, both sides of the Western Mediterranean were inhabited by hunter-gatherer groups which probably maintained intercontinental contacts. However, from around 7.6 ka calBP, Neolithic groups from the Eastern Mediterranean arrived in the region along the littoral of what is today Andalusia. Neolithic innovations were adopted step by step by local Epipalaeolithic groups and subsequently dispersed via already existing networks. At the same time indigenous elements were integrated into this transitional process. New 14C-data confirm the simultaneity of the Epipalaeolithic–Neolithic transition in southern Spain and northern Morocco. Results are discussed considering models and concepts from social anthropology dealing with migration and acculturation.


Technology, typology and use wear analysis of lithic tools during the early Neolithic in the cave of Murciélagos de Zuheros (Córdoba, Spain): Reflexions on the Neolithisation of the southern Iberian Peninsula
  • António Faustino Carvalhoa,  , 
  • Juan Francisco Gibajab, , 
  • Beatriz Gavilánc, 
  • a Instituto de Arqueologia e Paleociências das Universidades Nova de Lisboa e do Algarve, Universidade do Algarve, FCHS, Campus de Gambelas, 8000-117 Faro, Portugal
  • b Departamento de Arqueología del Consejo Superior de Investigaciones Científicas (CSIC-IMF), Investigador contratado por el Ministerio de Ciencia e Innovación - Subprograma Ramón y Cajal, C/Egipciàques, 15, 08001 Barcelona, Espagne
  • c Universidad de Huelva, Facultad de Humanidades, Campus del El Carmen, Avda, Tres de Marzo S/N, Espagne

Abstract

The cave of Murciélagos de Zuheros (Cordoba, Spain) is one of the most important sites in Southern Iberian Peninsula. Its thick chronostratigraphic sequence includes occupations ranging from the Middle Palaeolithic to Roman times. Occupation levels corresponding to the earliest farming communities that established in modern-day Andalucia are remarkable due to its archaeological richness. This article focuses on the study of the lithic industry from these Early Neolithic levels, which is approached according to various tightly connected questions: raw material characterization, technical systems of production, and morphology and function of tools. Obtained results in their archaeological context are related to the questions on the origin of the Neolithic in Southern Iberian Peninsula.

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