Paleogenetics Shed Light on Ancestry of the Inca

A multinational South American team from Peru, Brasil and Bolivia led by the Universidad de San Martin de Porres at Lima, Peru, published the first genetic study on the modern descendants of the imperial Inka lineages in the journal Molecular Genetics and Genomics. This work supported by funds from the Genographic Project (Geno 2.0), shows new insights about the Inkas origins and lineages.

The Inka people arrived to Cusco valley and in a few centuries they built the Tawantinsuyu, the largest empire in the Americas. The Tawantinsuyu was the cultural climax of 6,000 years of Central Andes civilizations overlapping modern countries of Peru, Bolivia, Ecuador, the South of Colombia and the North of Argentina and Chile. In contrast with the richness of archeological and cultural evidence, pre Columbian history vanishes in time as it intermingles with myths due to the lack of writing systems before the arrival of the European chroniclers. Very little is known about the Inka origins and some genetic information could help reconstruct part of their history. Unfortunately the mummies and bodily remains of the Inka emperors, worshiped as gods, were burnt and buried in unknown locations due to religious and political persecution by the Christian Conquistadors and Inquisitors, so no direct material remain to study their DNA. "Thus for now, only the genetic analysis of modern families of Inka descent could provide some clues about their ancestors" remarks geneticist Jose Sandoval, first author, working at Universidad de San Martin de Porres at Lima, Peru.

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Infant Head Shaping in PreColumbian Andes Examined

The idea of binding and reshaping a baby's head may make today's parents cringe, but for families in the Andes between 1100-1450, cranial modification was all the rage.

Like Chinese foot binding, the practice may have been a marker of group identity. Its period of popularity in what is now Peru, before the expansion of the Inca empire, was marked by political upheaval, ecological stress and the emergence of new cultural practices. In a study published in Current Anthropology, Matthew Velasco, assistant professor of anthropology at Cornell University, explores how head-shaping practices may have enabled political solidarity while furthering social inequality in the region.

Velasco analyzed hundreds of human skeletal remains from multiple tombs in the Colca Valley of highland Peru and discovered that before 1300 most people did not have modified heads. He found that the number of individuals with cranial modifications increased over time, from 39.2 percent to 73.7 percent during the later portion of the Late Intermediate Period.

Skeletal samples of two major ethnic groups showed that the Collaguas employed methods to make their heads assume a longer, narrower shape, while the Cavanas sought to make their heads wide and squat. Eventually, the elongated head shape of the Collaguas became the predominant style of modification in the upper Colca Valley. According to Velasco, this shift toward embodying a shared identity may have strengthened ties between groups engaged in protracted conflict with outsiders, including the Incas.

"The increased homogeny of head shapes suggests that modification practices contributed to the creation of a new collective identity and may have exacerbated emerging social differences," Velasco said. "Head shape would be an obvious signifier of affiliation and could have encouraged unity among elites and increased cooperation in politics."

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Did the PreColumbian Wari Empire Assimilate Rather Than Wipe out Areas?

The imperial dominance of the ancient Wari Empire at the Huaca Pucllana site in Lima, Peru, was likely not achieved through population replacement, according to a study published June 1, 2016 in the open-access journal PLOS ONE by Guido Valverde from the University of Adelaide, Australia, and colleagues.

Successive pre-Columbian civilizations existed in the central Andes of South America since the pre-ceramic period 5.5 kya, and ancient empires such as the Wari Empire (600 - 1100 AD) may have been important in shaping the region's demographic and cultural profiles. To investigate whether Wari dominance in the Peruvian Central Coast was based on population replacement or cultural diffusion, the authors of the present study sequenced the complete mitochondrial genomes of 34 individuals from the Huaca Pucllana archaeological site in Lima, Peru, who lived before, during, and after the Wari Empire, and assessed how the population's genetic diversity changed over time.

The researchers found that genetic diversity may only have changed subtly over this period, indicating population continuity over time with only minor genetic impact from Wari imperialism. The subtle genetic diversity shift found at this site may not be representative for the entire Wari territory, and more research is needed to characterize the overall influence of the Wari Empire. Nonetheless, the authors suggest that the Wari Empire may have exerted influence in this area through cultural diffusion rather than by replacement of the pre-existing population.

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Evidence of People From 12.5k Years ago in South-Central Andes

Radiocarbon dates and anthropogenic signal in the South-Central Andes (12,500–600 cal. years BP)

Authors:

Muscio et al

Abstract:

This paper presents the analysis of the anthropogenic signal documented by four time-series in the highlands of the South-Central Andes (Puna of Argentina and North Chile) spanning the period between 12,500 and 600 cal years BP. Our goal is to extract demographic and occupational histories from temporal data. In this way, based upon the full radiocarbon dataset and the sites of provenance of the dates, we built the following time-series: the summed probability distribution of calibrated ages; the relative frequency of calibrated ages; the relative frequency of sites per unit of time; and the frequency of new sites per unit of time. For controlling the effects of site destruction on the anthropogenic signal, we used the exponential model as well as the volcanic empirical model of taphonomic bias. The four time-series coincide in showing a regional pattern with a phase of low and fluctuating demography of relative long term duration, followed by an growth phase well evident at 5000 cal BP in a context the economic intensification. The long-term demographic success of the hunter-gatherers in the highlands many millennia before the consolidation of food production exemplifies the flexibility of this mode of subsistence for achieving human adaptation to extreme selective environments as the Puna.

An Alternate Model for the Growth of PreColumbian Tiwanaku

Multiethnicity, pluralism, and migration in the south central Andes: An alternate path to state expansion

Author:

Goldstein

Abstract:

The south central Andes is known as a region of enduring multiethnic diversity, yet it is also the cradle of one the South America’s first successful expansive-state societies. Social structures that encouraged the maintenance of separate identities among coexistent ethnic groups may explain this apparent contradiction. Although the early expansion of the Tiwanaku state (A.D. 600–1000) is often interpreted according to a centralized model derived from Old World precedents, recent archaeological research suggests a reappraisal of the socio-political organization of Tiwanaku civilization, both for the diversity of social entities within its core region and for the multiple agencies behind its wider program of agropastoral colonization. Tiwanaku’s sociopolitical pluralism in both its homeland and colonies tempers some of archaeology’s global assumptions about the predominant role of centralized institutions in archaic states.

First Genetically Adapted Population of Humans Tolerant of Arsenic Found

High up in the high Andes mountains of Argentina, researchers have identified the first-ever evidence of a population uniquely adapted to tolerate the toxic chemical arsenic.

For thousands of years, in some regions of the Andes, people have been exposed to high levels of arsenic, a naturally occurring phenomenon that happens when arsenic in the volcanic bedrock is released into the groundwater. How could this population adapt to tolerate arsenic, a potent killer of such ill repute that it's often the overused plot-driver of many murder mysteries?

In a new study published in the advanced online edition of Molecular Biology and Evolution, a Swedish research team led by Karolinska Institutet and Uppsala University professor Karin Broberg, performed a genome wide survey from a group of 124 Andean women screened for the ability to metabolize arsenic (measured by levels in the urine). The study pinpointed a key set of nucleotide variants in a gene, AS3MT, which were at much lower frequencies in control populations from Columbia and Peru. The researchers estimate that the increase in frequency of these variants occurred recently, between 10,000-7,000 years ago, based on the age of a recently excavated mummy that was found to have high arsenic levels in its hair.

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More Information About the Hettangian Jurassic/Post Triassic-Jurassic Mass Extinction Sponge Bob World

Andean sponges reveal long-term benthic ecosystem shifts following the end-Triassic mass extinction

Authors:

Ritterbush et al

Abstract:

Thick cherts and cherty dolomites in the basal Jurassic Aramachay Formation of Peru preserve a thriving continental shelf community dominated by siliceous sponges that followed the end-Triassic collapse of metazoan-rich carbonate accumulation. Similar Hettangian and Sineumurian deposits from Nevada, U.S.A., Austria, and Morocco suggest that an Early Jurassic siliceous sponge takeover was a widespread phenomenon that persisted for ~ 2 m.y. until metazoan-driven carbonate sedimentation recovered. The post-extinction dominance of siliceous sponges likely resulted from the confluence of metazoan carbonate reef collapse (removal of incumbents) and geochemical conditions that fostered the success of the siliceous sponge-dominated ecosystem. Simple mass balance calculations suggest the siliceous sponge takeover was likely permitted by an increased silica flux as a consequence of weathering Central Atlantic Magmatic Province (CAMP) basalts. The CAMP basalts alone could supply all the silica needed to sustain the sponge takeover, although contributions were also likely from increased hot-climate weathering of other silicates and possible reductions in dissolved silica demand by radiolarians. Detailed sedimentological, fossil, and microfacies analyses were conducted at six field sites across a shallow shelf system recorded in the central Peruvian Andes (Yauli Dome), focusing on the metazoan contribution to sedimentation. Sedimentary structures at all six sites demonstrated on-shelf deposition, similar to the underlying upper Triassic Chambará Formation (in contrast to the black shale-rich facies of the Aramachay Formation in other areas of Peru). Examination of up to 147 m of cherty dolomite from the Aramachay Formation revealed a siliceous sponge-dominated ecosystem, including sponge body fossils, compressed in situ sponge materials, and abundant transported spiculite sediments. Siliceous sponges, mostly demosponges and rare hexactinellids, account for the chert lithology and apparently dominated the local ecology for approximately two million years. The role of metazoan biocalcifiers in sediment production and ecological structure was profoundly reduced compared to the under- and overlying formations, representing a clear ecological state shift from pre-extinction carbonate to post-extinction siliceous dominated ecosystems before the carbonate system recovered ~ 2 m.y. after the extinction.

Maize Consumption in pre-Hispanic Andes

Maize consumption in pre-Hispanic south-central Andes: chemical and microscopic evidence from organic residues in archaeological pottery from western Tinogasta (Catamarca, Argentina)

Authors:

Lantos et al

Abstract:

Pre-Hispanic Andean societies depended economically on the cultivation of maize (Zea mays), the main staple food crop in the region after its introduction from highland Mexico. Here we report new data from residue analysis of potsherds recovered in archaeological sites in western Tinogasta, Catamarca province, Argentina, ca. 3rd to 16th centuries AD. Molecular and isotopic (δ13C values) compositions of fatty acids and microscopically identified maize starch granules from organic residues absorbed in archaeological potsherds were compared with Andean ingredients and food residues obtained from experimental replica pots, where traditional recipes were cooked. Complex mixtures of lipids and starch remains observed in archaeological cooking pots indicated combinations of Andean ingredients such as llama, beans, algarroba, and maize, and suggest continuity in the domestic foodways through time. The distribution and δ13C values of lipids preserved in vessels used for alcoholic beverage preparation, storage and transport in Inka sites suggested the possible consumption of two drinks with distinct patterns: traditional Andean maize beer (chicha) and a local fermented drink made from algarroba flour (aloja). This is potential evidence for consumption practices in festive contexts sponsored by the Inka state.

Pleistocene Archaelogy From the VERY High Abdes (almost 15,000 ft) Excavated

Research conducted at the highest-altitude Pleistocene archaeological sites yet identified in the world sheds new light on the capacity of humans to survive in extreme environments.

The findings, to be published in the Oct. 24 edition of the academic journal Science – co-authored by a team of researchers including University of Calgary archaeologist Sonia Zarrillo – were taken from sites in the Pucuncho Basin, located in the Southern Peruvian Andes.

The primary site, Cuncaicha is a rock shelter at 4,480 metres above sea level, with a stone-tool workshop below it. There is also a Pucuncho workshop site where stone tools were made at 4,355 metres above sea level. Climatic conditions in both sites are harsh, with factors including low-oxygen, extreme cold and high levels of solar radiation making life in the region a challenge for any humans. And yet, the findings indicate that people were living in these high altitude zones for extended periods of time. Cuncaicha was occupied about 12.4 to 11.5 thousand years ago while the Pucuncho workshop site dates to around 12.8 to 11.5 thousand years ago.

"We don't know if people were living there year round, but we strongly suspect they were not just going there to hunt for a few days, then leaving," says Zarrillo. "There were possibly even families living at these sites, because we've found evidence of a whole range of activities."

Archaeological evidence found at Cuncaicha includes signs of habitation such as human skull fragments, animal remains and stone tools. "Hunters passing through an area will take the meat back to campsites and leave the carcass in the field," says Zarrillo. "In Cuncaicha we found remains representing whole animals, indicating they were living close to where the animals were killed. And the types of stone tools we've found are not only hunting tools but also scraping tools used for processing hides to make things like clothing, bags or blankets."

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Evidence of Mountain Forests in Middle Pleistocene Andean Ecuador

Forests of the tropical eastern Andean flank during the middle Pleistocene

Authors:

Cárdenas et al

Abstract:

Inter-bedded volcanic and organic sediments from Erazo (Ecuador) indicate the presence of four different forest assemblages on the eastern Andean flank during the middle Pleistocene. Radiometric dates (40Ar–39Ar) obtained from the volcanic ash indicate that deposition occurred between 620,000 and 192,000 years ago. Examination of the organic sediment composition and the fossil pollen, wood and charcoal it contains provides insight into depositional environment, vegetation assemblage and fire history. The high organic content and abundance of macro fossils found throughout the sediment suggest that during the period of deposition the local environment was either a swamp or a shallow water body. The correlation of fire activity (peaks in charcoal abundance) with volcanic ash deposits through most of the record suggests that volcanoes were the main source of ignition. The low abundance of grass (typically less than 10%) throughout the sedimentary sequence along with the low abundance of other taxa indicative of open vegetation suggests the persistence of forest at Erazo. Four types of forest assemblage were identified (with the first taxa as the most dominant): i) Alnus-Arecaceae, ii) Miconia-Melastomataceae/Combretaceae-Moraceae/Urticaceae, iii) Arecaceae-Alnus, and iv) Podocarpus with Oreopanax sp. and Melastomataceae/Combretaceae. Changes in the forest floristic composition indicate high vegetation turnover and reassortment of taxa between upper and lower montane forests during the middle Pleistocene as well as the persistence of forest cover.

Andes Mountains Older Than Previously Thought

The geologic faults responsible for the rise of the eastern Andes mountains in Colombia became active 25 million years ago—18 million years before the previously accepted start date for the Andes' rise, according to researchers at the Smithsonian Tropical Research Institute in Panama, the University of Potsdam in Germany and Ecopetrol in Colombia.

“No one had ever dated mountain-building events in the eastern range of the Colombian Andes,” said Mauricio Parra, a former doctoral candidate at the University of Potsdam (now a postdoctoral fellow with the University of Texas) and lead author. “This eastern sector of America’s backbone turned out to be far more ancient here than in the central Andes, where the eastern ranges probably began to form only about 10 million years ago.”

The team integrated new geologic maps that illustrate tectonic thrusting and faulting, information about the origins and movements of sediments and the location and age of plant pollen in the sediments, as well as zircon-fission track analysis to provide an unusually thorough description of basin and range formation.

As mountain ranges rise, rainfall and erosion wash minerals like zircon from rocks of volcanic origin into adjacent basins, where they accumulate to form sedimentary rocks. Zircon contains traces of uranium. As the uranium decays, trails of radiation damage accumulate in the zircon crystals. At high temperatures, fission tracks disappear like the mark of a knife disappears from a soft block of butter. By counting the microscopic fission tracks in zircon minerals, researchers can tell how long ago sediments formed and how deeply they were buried.

Classification of nearly 17,000 pollen grains made it possible to clearly delimit the age of sedimentary layers.

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