Publications by authors named "Boris Gasparyan"

8 Publications

  • Page 1 of 1

Middle Pleistocene genome calibrates a revised evolutionary history of extinct cave bears.

Curr Biol 2021 Feb 9. Epub 2021 Feb 9.

School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK.

Palaeogenomes provide the potential to study evolutionary processes in real time, but this potential is limited by our ability to recover genetic data over extended timescales. As a consequence, most studies so far have focused on samples of Late Pleistocene or Holocene age, which covers only a small part of the history of many clades and species. Here, we report the recovery of a low coverage palaeogenome from the petrous bone of a ∼360,000 year old cave bear from Kudaro 1 cave in the Caucasus Mountains. Analysis of this genome alongside those of several Late Pleistocene cave bears reveals widespread mito-nuclear discordance in this group. Using the time interval between Middle and Late Pleistocene cave bear genomes, we directly estimate ursid nuclear and mitochondrial substitution rates to calibrate their respective phylogenies. This reveals post-divergence mitochondrial transfer as the dominant factor explaining their mito-nuclear discordance. Interestingly, these transfer events were not accompanied by large-scale nuclear introgression. However, we do detect additional instances of nuclear admixture among other cave bear lineages, and between cave bears and brown bears, which are not associated with mitochondrial exchange. Genomic data obtained from the Middle Pleistocene cave bear petrous bone has thus facilitated a revised evolutionary history of this extinct megafaunal group. Moreover, it suggests that petrous bones may provide a means of extending both the magnitude and time depth of palaeogenome retrieval over substantial portions of the evolutionary histories of many mammalian clades.
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http://dx.doi.org/10.1016/j.cub.2021.01.073DOI Listing
February 2021

Short-term occupations at high elevation during the Middle Paleolithic at Kalavan 2 (Republic of Armenia).

PLoS One 2021 4;16(2):e0245700. Epub 2021 Feb 4.

Institute of Archaeology and Ethnography, National Academy of Sciences of the Republic of Armenia, Yerevan, Armenia.

The Armenian highlands encompasses rugged and environmentally diverse landscapes and is characterized by a mosaic of distinct ecological niches and large temperature gradients. Strong seasonal fluctuations in resource availability along topographic gradients likely prompted Pleistocene hominin groups to adapt by adjusting their mobility strategies. However, the role that elevated landscapes played in hunter-gatherer settlement systems during the Late Pleistocene (Middle Palaeolithic [MP]) remains poorly understood. At 1640 m above sea level, the MP site of Kalavan 2 (Armenia) is ideally positioned for testing hypotheses involving elevation-dependent seasonal mobility and subsistence strategies. Renewed excavations at Kalavan 2 exposed three main occupation horizons and ten additional low densities lithic and faunal assemblages. The results provide a new chronological, stratigraphical, and paleoenvironmental framework for hominin behaviors between ca. 60 to 45 ka. The evidence presented suggests that the stratified occupations at Kalavan 2 locale were repeated ephemerally most likely related to hunting in a high-elevation within the mountainous steppe landscape.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0245700PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7861461PMC
February 2021

Ancient DNA suggests modern wolves trace their origin to a Late Pleistocene expansion from Beringia.

Mol Ecol 2020 05 2;29(9):1596-1610. Epub 2020 Jan 2.

Department of Zoology, University of Cambridge, Cambridge, UK.

Grey wolves (Canis lupus) are one of the few large terrestrial carnivores that have maintained a wide geographical distribution across the Northern Hemisphere throughout the Pleistocene and Holocene. Recent genetic studies have suggested that, despite this continuous presence, major demographic changes occurred in wolf populations between the Late Pleistocene and early Holocene, and that extant wolves trace their ancestry to a single Late Pleistocene population. Both the geographical origin of this ancestral population and how it became widespread remain unknown. Here, we used a spatially and temporally explicit modelling framework to analyse a data set of 90 modern and 45 ancient mitochondrial wolf genomes from across the Northern Hemisphere, spanning the last 50,000 years. Our results suggest that contemporary wolf populations trace their ancestry to an expansion from Beringia at the end of the Last Glacial Maximum, and that this process was most likely driven by Late Pleistocene ecological fluctuations that occurred across the Northern Hemisphere. This study provides direct ancient genetic evidence that long-range migration has played an important role in the population history of a large carnivore, and provides insight into how wolves survived the wave of megafaunal extinctions at the end of the last glaciation. Moreover, because Late Pleistocene grey wolves were the likely source from which all modern dogs trace their origins, the demographic history described in this study has fundamental implications for understanding the geographical origin of the dog.
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http://dx.doi.org/10.1111/mec.15329DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7317801PMC
May 2020

Geochemical Evidence for the Control of Fire by Middle Palaeolithic Hominins.

Sci Rep 2019 10 25;9(1):15368. Epub 2019 Oct 25.

Department of Anthropology, University of Connecticut, Storrs, CT, USA.

The use of fire played an important role in the social and technological development of the genus Homo. Most archaeologists agree that this was a multi-stage process, beginning with the exploitation of natural fires and ending with the ability to create fire from scratch. Some have argued that in the Middle Palaeolithic (MP) hominin fire use was limited by the availability of fire in the landscape. Here, we present a record of the abundance of polycyclic aromatic hydrocarbons (PAHs), organic compounds that are produced during the combustion of organic material, from Lusakert Cave, a MP site in Armenia. We find no correlation between the abundance of light PAHs (3-4 rings), which are a major component of wildfire PAH emissions and are shown to disperse widely during fire events, and heavy PAHs (5-6 rings), which are a major component of particulate emissions of burned wood. Instead, we find heavy PAHs correlate with MP artifact density at the site. Given that hPAH abundance correlates with occupation intensity rather than lPAH abundance, we argue that MP hominins were able to control fire and utilize it regardless of the variability of fires in the environment. Together with other studies on MP fire use, these results suggest that the ability of hominins to manipulate fire independent of exploitation of wildfires was spatially variable in the MP and may have developed multiple times in the genus Homo.
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http://dx.doi.org/10.1038/s41598-019-51433-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6814844PMC
October 2019

The earliest evidence for Upper Paleolithic occupation in the Armenian Highlands at Aghitu-3 Cave.

J Hum Evol 2017 09 7;110:37-68. Epub 2017 Jul 7.

Zinman Institute of Archaeology, University of Haifa, Mount Carmel, 31905, Israel.

With its well-preserved archaeological and environmental records, Aghitu-3 Cave permits us to examine the settlement patterns of the Upper Paleolithic (UP) people who inhabited the Armenian Highlands. We also test whether settlement of the region between ∼39-24,000 cal BP relates to environmental variability. The earliest evidence occurs in archaeological horizon (AH) VII from ∼39-36,000 cal BP during a mild, moist climatic phase. AH VI shows periodic occupation as warm, humid conditions prevailed from ∼36-32,000 cal BP. As the climate becomes cooler and drier at ∼32-29,000 cal BP (AH V-IV), evidence for occupation is minimal. However, as cooling continues, the deposits of AH III demonstrate that people used the site more intensively from ∼29-24,000 cal BP, leaving behind numerous stone artifacts, faunal remains, and complex combustion features. Despite the climatic fluctuations seen across this 15,000-year sequence, lithic technology remains attuned to one pattern: unidirectional reduction of small cores geared towards the production of bladelets for tool manufacture. Subsistence patterns also remain stable, focused on medium-sized prey such as ovids and caprids, as well as equids. AH III demonstrates an expansion of social networks to the northwest and southwest, as the transport distance of obsidian used to make stone artifacts increases. We also observe the addition of bone tools, including an eyed needle, and shell beads brought from the east, suggesting that these people manufactured complex clothing and wore ornaments. Remains of micromammals, birds, charcoal, pollen, and tephra relate the story of environmental variability. We hypothesize that UP behavior was linked to shifts in demographic pressures and climatic changes. Thus, by combining archaeological and environmental data, we gain a clearer picture about the first UP inhabitants of the Armenian Highlands.
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http://dx.doi.org/10.1016/j.jhevol.2017.05.010DOI Listing
September 2017

The altitudinal mobility of wild sheep at the Epigravettian site of Kalavan 1 (Lesser Caucasus, Armenia): Evidence from a sequential isotopic analysis in tooth enamel.

J Hum Evol 2016 08 12;97:27-36. Epub 2016 Jun 12.

Aix Marseille Université, CNRS, MCC, LAMPEA UMR 7269, 13094 Aix-en-Provence, France. Electronic address:

Kalavan 1 is an Epigravettian hunting campsite in the Aregunyats mountain chain in northeastern Armenia (Lesser Caucasus). The site lies at an elevation of 1640 m in a bottleneck that controls the descent into the Barepat Valley from the alpine meadows above. The lithic and faunal assemblages show evidence of the production of hunting weapons, the hunting and targeting of wild sheep (Ovis orientalis), and the constitution of animal product reserves. A seasonal occupation of the site was proposed within a model of occupation by Epigravettian hunter-gatherers that involved a search for obsidian resources in high altitude sources from the spring to the summer and settling at Kalavan 1 at the end of summer or during autumn to coincide with the migration of wild herds from the alpine meadows to the valley. A key parameter of this model is wild sheep ethology, with a specifically seasonal vertical mobility, based on observations from contemporary mouflon populations from the surrounding areas. In this study, the vertical mobility of Paleolithic wild sheep was directly investigated through sequential isotope analysis (δ(18)O, δ(13)C) in teeth. A marked seasonality of birth is suggested that reflects a physiological adaptation to the strong environmental constraints of this mountainous region. Most importantly, a recurrent altitudinal mobility was demonstrated on a seasonal basis, which confirms that wild sheep migrated from lowland areas that they occupied in the winter and then moved to higher altitude meadows during the summer. Last, low inter-individual variability in the stable isotope sequences favors a hypothesis of accumulation for these faunal remains over a short time period. Overall, this new dataset strengthens the previous interpretations for Kalavan 1 and contributes to an understanding of the pattern of occupation of mountain territories by Epigravettian communities.
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http://dx.doi.org/10.1016/j.jhevol.2016.05.001DOI Listing
August 2016

Middle Palaeolithic toolstone procurement behaviors at Lusakert Cave 1, Hrazdan valley, Armenia.

J Hum Evol 2016 Feb 31;91:73-92. Epub 2015 Dec 31.

Department of Anthropology, Old World Archaeology Program, University of Connecticut, 354 Mansfield Road, Unit 1176, Storrs, CT 06269, United States.

Strategies employed by Middle Palaeolithic hominins to acquire lithic raw materials often play key roles in assessing their movements through the landscape, relationships with neighboring groups, and cognitive abilities. It has been argued that a dependence on local resources is a widespread characteristic of the Middle Palaeolithic, but how such behaviors were manifested on the landscape remains unclear. Does an abundance of local toolstone reflect frequent encounters with different outcrops while foraging, or was a particular outcrop favored and preferentially quarried? This study examines such behaviors at a finer geospatial scale than is usually possible, allowing us to investigate hominin movements through the landscape surrounding Lusakert Cave 1 in Armenia. Using our newly developed approach to obsidian magnetic characterization, we test a series of hypotheses regarding the locations where hominins procured toolstone from a volcanic complex adjacent to the site. Our goal is to establish whether the cave's occupants procured local obsidian from preferred outcrops or quarries, secondary deposits of obsidian nodules along a river, or a variety of exposures as encountered while moving through the river valley or across the wider volcanic landscape during the course of foraging activities. As we demonstrate here, it is not the case that one particular outcrop or deposit attracted the cave occupants during the studied time intervals. Nor did they acquire obsidian at random across the landscape. Instead, our analyses support the hypothesis that these hominins collected obsidian from outcrops and exposures throughout the adjacent river valley, reflecting the spatial scale of their day-to-day foraging activities. The coincidence of such behaviors within the resource-rich river valley suggests efficient exploitation of a diverse biome during a time interval immediately preceding the Middle to Upper Palaeolithic "transition," the nature and timing of which has yet to be determined for the region.
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http://dx.doi.org/10.1016/j.jhevol.2015.10.008DOI Listing
February 2016

The Upper Palaeolithic site of Kalavan 1 (Armenia): an Epigravettian settlement in the Lesser Caucasus.

J Hum Evol 2013 Nov 18;65(5):621-40. Epub 2013 Sep 18.

Aix Marseille Université, CNRS, MCC, LAMPEA UMR 7269, 13094 Aix-en-Provence, France; DRAC Picardie, Service Régional de l'Archéologie, 5 rue Henri Daussy, 80 000 Amiens, France. Electronic address:

The open-air site of Kalavan 1 is located in the Aregunyats mountain chain (at 1640 m above sea level) on the northern bank of Lake Sevan. It is the first Upper Palaeolithic site excavated in Armenia. Led by an Armenian-French team, several excavations (2005-2009) have revealed a well preserved palaeosoil, dated to around 14,000 BP (years before present), containing fauna, lithic artefacts, as well as several hearths and activity areas that structure the settlement. The initial studies enable placement of the site in its environment and justify palaeoethnological analysis of the Epigravettian human groups of the Lesser Caucasus.
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http://dx.doi.org/10.1016/j.jhevol.2013.07.011DOI Listing
November 2013