Mitochondrial phylogeography and demographic history of the Vicuña: implications for conservation

The vicuña (Vicugna vicugna; Miller, 1924) is a conservation success story, having recovered from near extinction in the 1960s to current population levels estimated at 275 000. However, lack of information about its demographic history and genetic diversity has limited both our understanding of its recovery and the development of science-based conservation measures. To examine the evolution and recent demographic history of the vicuña across its current range and to assess its genetic variation and population structure, we sequenced mitochondrial DNA from the control region (CR) for 261 individuals from 29 populations across Peru, Chile and Argentina. Our results suggest that populations currently designated as Vicugna vicugna vicugna and Vicugna vicugna mensalis comprise separate mitochondrial lineages. The current population distribution appears to be the result of a recent demographic expansion associated with the last major glacial event of the Pleistocene in the northern (18 to 22°S) dry Andes 14–12 000 years ago and the establishment of an extremely arid belt known as the 'Dry Diagonal' to 29°S. Within the Dry Diagonal, small populations of V. v. vicugna appear to have survived showing the genetic signature of demographic isolation, whereas to the north V. v. mensalis populations underwent a rapid demographic expansion before recent anthropogenic impacts

An Inka Offering at Yayno (North Highlands, Peru): Objects, Subjects and Gifts in the Ancient Andes

While Marcel Mauss's landmark essay on The Gift has been vital in social anthropology, inspiring a vast and influential secondary literature, the gift has been much less prominent in archaeological interpretation. This study considers evidence for an ancient Andean gift economy, a system of reciprocal exchanges focused on making people and ensuring group social relations, rather than accumulating wealth/capital. Excavations at Yayno (north highlands, Ancash, Peru) revealed two features dating to the time of the Inkas: 1) a slab-lined cist burial; and 2) an offering deposit containing abundant long-distance trade and sumptuary items. Besides its mountaintop location, the burial's intrusive character and foreign items indicate that the offerings were made to propitiate the place, ruins and their divine aspect. This essay studies the reciprocal acts that led to the offerings, comparing them to gifting patterns in Inka human sacrifices known as capac hucha. The key actors in the exchange were children, divinities, Inka bureaucrats, local leaders and state subjects

Reconstructing the Deep Population History of Central and South America

We report genome-wide ancient DNA from 49 individuals forming four parallel time transects in Belize, Brazil, the Central Andes, and the Southern Cone, each dating to at least 9,000 years ago. The common ancestral population radiated rapidly from just one of the two early branches that contributed to Native Americans today. We document two previously unappreciated streams of gene flow between North and South America. One affected the Central Andes by 4,200 years ago, while the other explains an affinity between the oldest North American genome associated with the Clovis culture and the oldest Central and South Americans from Chile, Brazil, and Belize. However, this was not the primary source for later South Americans, as the other ancient individuals derive from lineages without specific affinity to the Clovis-associated genome, suggesting a population replacement that began at least 9,000 years ago and was followed by substantial population continuity in multiple regions

Contribution à l'étude de la structure et des propriétés mécaniques des dépots électrolytiques de cobalt en vue d'optimiser leur ductilité

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

On the Resolution of 14

We submit that anomalies in radiocarbon data in archaeological studies should be viewed positively as a stimulus to undertake further targeted research. Additional analyses to resolve anomalies have the potential to provide important insights into heretofore unstudied or incompletely understood depositional or geochemical processes affecting 14C values, particularly in certain types of samples and samples from certain types of environments. We consider 2 major categories or sources of 14C dating anomalies that we posit are mostly responsible for the vast majority of problematic 14C results: anomalous sample contexts and anomalous sample composition. Two additional sources of 14C anomalies are much more rarely encountered. Six case studies taken from New World archaeological studies are briefly presented to provide examples of where questions concerning the validity of 14C measurements generated additional and ultimately more accurate understandings of temporal relationships. AMS-based 14C measurement technology has rendered detailed investigations of 14C anomalies routinely feasible.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202