Mark Aldenderfer

The Pleistocene/Holocene transition in Peru and its effects upon human use of the landscape

Abstract This paper reviews the state of our knowledge regarding the effects of the Pleistocene/Holocene transition on the kinds and range of human adaptations in what is now Peru. Following a discussion of geological, paleoclimatic, and archaeological data, the paper focuses upon four aspects of environmental change with specific regard to how these would have affected human adaptations: environmental changes on the Pacific littoral, the extinction of Pleistocene faunal and floral species and their replacement with modern faunas, the adaptive radiation of these modern flora and fauna, especially into the Andean highlands, and characteristics of newly available high elevation environments that would have affected the process by which foraging peoples moved into them. Although Pleistocene fauna have been discovered in Peru, none of these finds have been made in the context of indisputable human activity, and therefore, the effect of their extinction on early foraging peoples is unknown. The earliest acceptable archaeological sites in Peru date around 11–12,000 years ago, and are found on the coastal lowlands. The highlands were not occupied until after 11,000 years ago. While high elevation environments were attractive after 11,000 years ago, they were only slowly occupied by humans due to the constraints of the combined effects of hypoxia and cold.

Fluvial history of the Rio Ilave valley, Peru, and its relationship to climate and human history

Fluvial strata and landforms in the Rio Ilave valley (Peru) document a history of Holocene aggradation and downcutting that is correlative with regional climatic events and provides an environmental context for human occupation of the river valley. Periods of aggradation correspond to periods of high (or rising) level in Lake Titicaca and elsewhere on the Altiplano, and increased sediment accumulation in the Rio Ilave valley. Downcutting episodes correspond to periods of low level in Lake Titicaca and low or rapidly decreasing sedimentation rates in the Ilave delta. There are five terrace tracts (T1 through T5) present in this southwestern Lake Titicaca tributary. These tracts occur as both paired and unpaired terraces and have average heights from 1.4 to 24.3 m above the valley floor. The major part of the fluvial sequence was deposited during the time period from prior to the Last Glacial Maximum until about 8300 calendar years Before Present (cal BP) ^ a period of generally high (but variable) precipitation on the Altiplano and high water level in Lake Titicaca. Initial deposition (aggradation) was followed by successive downcutting to the T4 and T3 terrace surfaces. Initial downcutting began immediately after precipitation, runoff, and sediment load decreased while base level dropped. It was followed by a period of episodic equilibrium and minor downcutting that included a prolonged period of soil formation between V8350 and 6780 cal BP. The major pulses of downcutting likely occurred between V6000 and 4500 cal BP and were coincident with periods of decreased precipitation on the Altiplano and decreasing levels of Lake Titicaca. Two final periods of infilling, resulting in deposition of the T2 and T1 terrace sediments at V4000 to 2500 cal BP and V2000 to 1600 cal BP (during periods of rising water level in Lake Titicaca, lacustrine sedimentation in the Rio Desaguadero valley, and increased sedimentation offshore the Ilave delta), were separated by brief equilibrium stages and a brief downcutting event. This fluvial history, when coupled with regional paleoclimatic data, relates to the region’s preceramic through Tiwanakuperiod archeological records. Archeological evidence indicates that humans occupied the Ilave valley as early as 10 000 cal BP. The higher terraces (T3, T4 and T5) were occupied for at least 5000 years, but humans did not utilize the lower terraces (T1 and T2) until after V4400^3700 cal BP. Our results confirm that these lower terraces would not have been available for either occupation or agriculture until after V4000 cal BP. ; 2003 Published by Elsevier Science B.V.

Intrinsic challenges in ancient microbiome reconstruction using 16S rRNA gene amplification

To date, characterization of ancient oral (dental calculus) and gut (coprolite) microbiota has been primarily accomplished through a metataxonomic approach involving targeted amplification of one or more variable regions in the 16S rRNA gene. Specifically, the V3 region (E. coli 341–534) of this gene has been suggested as an excellent candidate for ancient DNA amplification and microbial community reconstruction. However, in practice this metataxonomic approach often produces highly skewed taxonomic frequency data. In this study, we use non-targeted (shotgun metagenomics) sequencing methods to better understand skewed microbial profiles observed in four ancient dental calculus specimens previously analyzed by amplicon sequencing. Through comparisons of microbial taxonomic counts from paired amplicon (V3 U341F/534R) and shotgun sequencing datasets, we demonstrate that extensive length polymorphisms in the V3 region are a consistent and major cause of differential amplification leading to taxonomic bias in ancient microbiome reconstructions based on amplicon sequencing. We conclude that systematic amplification bias confounds attempts to accurately reconstruct microbiome taxonomic profiles from 16S rRNA V3 amplicon data generated using universal primers. Because in silico analysis indicates that alternative 16S rRNA hypervariable regions will present similar challenges, we advocate for the use of a shotgun metagenomics approach in ancient microbiome reconstructions.

Long-term genetic stability and a high-altitude East Asian origin for the peoples of the high valleys of the Himalayan arc

Significance Since prehistory, the Himalayan mountain range has presented a formidable barrier to population migration, whereas at the same time its transverse valleys have long served as conduits for trade and exchange. Yet, despite the economic and cultural importance of Himalayan trade routes, little is known about the region’s peopling and early population history. In this study, we conduct to our knowledge the first ancient DNA investigation of the Himalayan arc and generate genome data for eight individuals ranging in time from the earliest known human settlements to the establishment of the Tibetan Empire. We demonstrate that the region was colonized by East Asians of likely high-altitude origin, followed by millennia of genetic continuity despite marked changes in material culture and mortuary behavior. The high-altitude transverse valleys [>3,000 m above sea level (masl)] of the Himalayan arc from Arunachal Pradesh to Ladahk were among the last habitable places permanently colonized by prehistoric humans due to the challenges of resource scarcity, cold stress, and hypoxia. The modern populations of these valleys, who share cultural and linguistic affinities with peoples found today on the Tibetan plateau, are commonly assumed to be the descendants of the earliest inhabitants of the Himalayan arc. However, this assumption has been challenged by archaeological and osteological evidence suggesting that these valleys may have been originally populated from areas other than the Tibetan plateau, including those at low elevation. To investigate the peopling and early population history of this dynamic high-altitude contact zone, we sequenced the genomes (0.04×–7.25×, mean 2.16×) and mitochondrial genomes (20.8×–1,311.0×, mean 482.1×) of eight individuals dating to three periods with distinct material culture in the Annapurna Conservation Area (ACA) of Nepal, spanning 3,150–1,250 y before present (yBP). We demonstrate that the region is characterized by long-term stability of the population genetic make-up despite marked changes in material culture. The ancient genomes, uniparental haplotypes, and high-altitude adaptive alleles suggest a high-altitude East Asian origin for prehistoric Himalayan populations.

Reflexiones para avanzar en los estudios del período arcaico en Los Andes centro -sur

Los autores identifican los problemas de investigacion del Periodo Arcaico (10.000-3.400 a.p.) en la zona Centro-Sur de los Andes, para sugerir las prioridades que se deben tomar en cuenta para la realizacion de futuros estudios arqueologicos en la region. Varios temasarqueologicosaunpermanecen inconclusos:(1)Losorigenes delosprimeroshabitantesdelosAndesCentro-Sur.?Pordonde llegaron, en que condiciones climaticas, cual fue la cultura material que aportaron y como se dio el paso hacia el periodo Arcaico? (2) ?Que se conoce del tiempo arcaico en los flancos orientales de los Andes? (3) ?Donde se observa el Arcaico boliviano y cuales son sus caracteristicas? (4) ?Cual fue la adaptacion del Arcaico en la zona peruana del Lago Titicaca? (5) ?Cual es el estado de la cronologia regional que hemos construido para el Arcaico? ?Que estudios se han hecho y cuanto falta por hacer? Por ultimo, concluimos con una discusion de tres aspectos principales del proceso cultural de la region: (a) las adaptaciones de los primeros habitantes de la region, (b) el proceso de domesticacion del ganado y la cultivacion agricola, y (c) el inicio y origen del desarrollo de la sociedad compleja y la jerarquia social.

Quantitative Methods in Archaeology: A Review of Recent Trends and Developments

This paper reviews recent developments in the application of quantitative methods to archaeological research and focuses upon three major themes: the development of so-called designer methods, which are quantitative methods created to solve specific problems; the resurgence of whole-society modeling through a variety of formal and mathematical approaches; and trends in the the teaching of quantitative methods at the undergraduate and graduate levels. Not surprisingly, different subfields have had greater success than others in the development of useful methods, and the causes of this are explored. Finally, suggestions for improving training in the use of these methods are offered.

Settlement-Size Scaling among Prehistoric Hunter-Gatherer Settlement Systems in the New World

Settlement size predicts extreme variation in the rates and magnitudes of many social and ecological processes in human societies. Yet, the factors that drive human settlement-size variation remain poorly understood. Size variation among economically integrated settlements tends to be heavy tailed such that the smallest settlements are extremely common and the largest settlements extremely large and rare. The upper tail of this size distribution is often formalized mathematically as a power-law function. Explanations for this scaling structure in human settlement systems tend to emphasize complex socioeconomic processes including agriculture, manufacturing, and warfare—behaviors that tend to differentially nucleate and disperse populations hierarchically among settlements. But, the degree to which heavy-tailed settlement-size variation requires such complex behaviors remains unclear. By examining the settlement patterns of eight prehistoric New World hunter-gatherer settlement systems spanning three distinct environmental contexts, this analysis explores the degree to which heavy-tailed settlement-size scaling depends on the aforementioned socioeconomic complexities. Surprisingly, the analysis finds that power-law models offer plausible and parsimonious statistical descriptions of prehistoric hunter-gatherer settlement-size variation. This finding reveals that incipient forms of hierarchical settlement structure may have preceded socioeconomic complexity in human societies and points to a need for additional research to explicate how mobile foragers came to exhibit settlement patterns that are more commonly associated with hierarchical organization. We propose that hunter-gatherer mobility with preferential attachment to previously occupied locations may account for the observed structure in site-size variation.

Late Preceramic ceremonial architecture at Asana, southern Peru

Ceremonial architecture over 4600 years old has been discovered at the open air site of Asana in the high sierra of southern Peru – the best part of a thousand years earlier than in the central Andean sierra and with different architectural detail, form and content. This discovery provides new insights into a new regional architectural tradition and an alternative trajectory for the evolution of settled village life in the Andean highlands

Late Archaic-Early Formative period microbotanical evidence for potato at Jiskairumoko in the Titicaca Basin of southern Peru.

Significance The potato is perhaps the most important of the high Andean crops. Cultivated the length of the Andean cordillera and across disparate ecological zones, it is now also a principal global staple. For this study, we analyzed starch microremains recovered from 14 groundstone tools from Late Archaic to Early Formative period contexts at Jiskairumoko, an early village site in the Titicaca Basin of the south-central Andes of Peru. A total of 50 starches were identified as consistent with cultivated potato. These data are significant because they contribute to the empirical foundation for understanding the development of food production in the study area and underscore the utility of starch analysis in addressing questions relating to geophyte domestication and cultivation. The data presented in this paper provide direct microbotanical evidence concerning the early use of potato (Solanum tuberosum) within its botanical locus of origin in the high south-central Andes. The data derive from Jiskairumoko, an early village site in the western Titicaca Basin dating to the Late Archaic to Early Formative periods (∼3,400 cal y BC to 1,600 cal y BC). Because the site reflects the transition to sedentism and food production, these data may relate to potato domestication and early cultivation. Of 141 starch microremains recovered from 14 groundstone tools from Jiskairumoko, 50 are identified as consistent with cultivated or domesticated potato, based on reference to published materials and a study of wild and cultivated potato starch morphology. Along with macro- and microbotanical evidence for chenopod consumption and grinding tool data reflecting intensive use of this technology throughout site occupation, the microbotanical data reported here suggest the intensive exploitation, if not cultivation, of plant resources at Jiskairumoko. Elucidating the details of the trajectory of potato domestication is necessary for an overall understanding of the development of highland Andean agriculture, as this crop is central to the autochthonous agricultural suite. A paucity of direct botanical evidence, however, has hindered research efforts. The results of the modern and archaeological starch analyses presented here underscore the utility of this method in addressing questions related to the timing, mode, and context of potato origins.

Textile technology in Nepal in the 5th-7th centuries CE: the case of Samdzong

Abstract The first results of textile and dye analyses of cloth remains recovered in Samdzong, Upper Mustang, Nepal, are presented. The site consists of ten shaft tombs, dated between the 400-650 CE, cut into a high cliff face at an elevation of 4000 m asl. The dry climate and high altitude favoured the exceptional preservation of organic materials. One of the objects recovered from the elite Samdzong 5 tomb complex is composed of wool fabrics to which copper, glass and cloth beads are attached and probably constitutes the remains of a complex decorative headwear, which may have been attached to a gold/silver mask. SEM was used to identify the fibre sources of the textiles, which are all of animal nature. Two of the textiles are made of degummed silk. There is no evidence for local silk production suggesting that Samdzong was inserted into the long-distance trade network of the Silk Road. HPLC-DAD analysis permitted identification of a variety of organic dyes, including Indian lac, munjeet, turmeric and knotweed/indigo, while cinnabar was identified through micro Raman spectrometry. The results indicate that locally produced materials were used in combination with those likely imported from afar, including China and India. Statement of significance Textiles are not commonly found in most archaeological contexts, yet when preserved in organic state they can be analysed using modern scientific techniques such as Scanning Electron Microscopy and High Performance Liquid Chromatography to uncover information about their fibre and dye sources. This information can be used to reconstruct the economic and social aspects of textile production and exchange in the past. Identification of silk fibres and munjeet and Indian lac dyes in the textile finds from Samdzong, Nepal suggests that imported materials were used in combination with those locally produced. Data availability The authors confirm that all data underlying the findings are fully available without restriction. All relevant data are contained within the paper.