Alissa Mittnik

Genome-wide ancient DNA analysis of skeletons retrieved from archaeological excavations has provided a powerful new tool for the investigation of past populations and migrations. An important objective for the coming years is to properly integrate ancient genomics into archaeological research. This article aims to contribute to developing a better understanding and cooperation between the two disciplines and beyond. It focuses on the question of how best to name clusters encountered when analysing the genetic makeup of past human populations. Recent studies have frequently borrowed archaeological cultural designations to name these genetic groups, while neglecting the historically problematic nature of the concept of cultures in archaeology. After reviewing current practices in naming genetic clusters, we introduce three possible nomenclature systems (‘numeric system’, ‘mixed system (a)’, ‘geographic-temporal system’) along with their advantages and challenges.

Genome-wide ancient DNA analysis of skeletons retrieved from archaeological excavations has provided a powerful new tool for the investigation of past populations and migrations. An important objective for the coming years is to properly integrate ancient genomics into archaeological research. This article aims to contribute to developing a better understanding and cooperation between the two disciplines and beyond. It focuses on the question of how best to name clusters encountered when analysing the genetic makeup of past human populations. Recent studies have frequently borrowed archaeological cultural designations to name these genetic groups, while neglecting the historically problematic nature of the concept of cultures in archaeology. After reviewing current practices in naming genetic clusters, we introduce three possible nomenclature systems ('numeric system', 'mixed system (a)', 'geographic-temporal system') along with their advantages and challenges. Recent methodological advances including the advent of second generation short read sequencing technologies, the application of targeted hybridisation capture, and the recognition of petrous bones as rich sources for preservation of DNA, have transformed ancient DNA analysis into a revolutionary new tool for investigating the past 1–4. The exponential increase in the publication of ancient genomes, however, has not been matched by the development of a theoretical framework for the discussion of ancient DNA results and their contextualisation within the fields of history and archaeology 5. A particularly striking instance of this is given by two ancient DNA papers published in 2015 by Haak et al. and Allentoft et al. that detected fundamental changes in the central European gene pool during the 3 rd millennium BCE due to a massive gene influx ultimately deriving from the Pontic steppe region 6,7. They revived the discussion of large-scale migrations in prehistory, an idea that had been substantially dismissed in archaeology since the 1960s 8,9. The genetic evidence for large-scale movements of people became undeniable in light of the DNA data, and so the question was no longer about whether ancient DNA analysis can be trusted, but how the results should be interpreted and presented. For example Furholt 2016, Vander Linden 2016, and Heyd 2017 all accepted the genetic findings, but expressed concern that the studies did not sufficiently deal with the complexities of migrations in that they summarised their findings with simplified migration models involving groups of people (populations) moving

From around 2750 to 2500 bc, Bell Beaker pottery became widespread across western and central Europe, before it disappeared between 2200 and 1800 bc. The forces that propelled its expansion are a matter of long-standing debate, and there is support for both cultural diffusion and migration having a role in this process. Here we present genome-wide data from 400 Neolithic, Copper Age and Bronze Age Europeans, including 226 individuals associated with Beaker-complex artefacts. We detected limited genetic affinity between Beaker-complex-associated individuals from Iberia and central Europe, and thus exclude migration as an important mechanism of spread between these two regions. However, migration had a key role in the further dissemination of the Beaker complex. We document this phenomenon most clearly in Britain, where the spread of the Beaker complex introduced high levels of steppe-related ancestry and was associated with the replacement of approximately 90% of Britain’s gene pool within a few hundred years, continuing the east-to-west expansion that had brought steppe-related ancestry into central and northern Europe over the previous centuries.

Iñigo Olalde, Selina Brace, Morten E. Allentoft, Ian Armit, Kristian Kristiansen, Thomas Booth, Nadin Rohland, Swapan Mallick, Anna Szécsényi-Nagy, Alissa Mittnik, Eveline Altena, Mark Lipson, Iosif Lazaridis, Thomas K. Harper, Nick Patterson, Nasreen Broomandkhoshbacht, Yoan Diekmann, Zuzana Faltyskova, Daniel Fernandes, Matthew Ferry, Eadaoin Harney, Peter de Knijff, Megan Michel, Jonas Oppenheimer, Kristin Stewardson, Alistair Barclay, Kurt Werner Alt, Corina Liesau, Patricia Ríos, Concepción Blasco, Jorge Vega Miguel, Roberto Menduiña García, Azucena Avilés Fernández, Eszter Bánffy, Maria Bernabò-Brea, David Billoin, Clive Bonsall, Laura Bonsall, Tim Allen, Lindsey Büster, Sophie Carver, Laura Castells Navarro, Oliver E. Craig, Gordon T. Cook, Barry Cunliffe, Anthony Denaire, Kirsten Egging Dinwiddy, Natasha Dodwell, Michal Ernée, Christopher Evans, Milan Kuchařík, Joan Francès Farré, Chris Fowler, Michiel Gazenbeek, Rafael Garrido Pena, María Haber-Uriarte, Elżbieta Haduch, Gill Hey, Nick Jowett, Timothy Knowles, Ken Massy, Saskia Pfrengle, Philippe Lefranc, Olivier Lemercier, Arnaud Lefebvre, César Heras Martínez, Virginia Galera Olmo, Ana Bastida Ramírez, Joaquín Lomba Maurandi, Tona Majó, Jacqueline I. McKinley, Kathleen McSweeney, Balázs Gusztáv Mende, Alessandra Mod, Gabriella Kulcsár, Viktória Kiss, András Czene, Róbert Patay, Anna Endrődi, Kitti Köhler, Tamás Hajdu, Tamás Szeniczey, János Dani, Zsolt Bernert, Maya Hoole, Olivia Cheronet, Denise Keating, Petr Velemínský, Miroslav Dobeš, Francesca Candilio, Fraser Brown, Raúl Flores Fernández, Ana-Mercedes Herrero-Corral, Sebastiano Tusa, Emiliano Carnieri, Luigi Lentini, Antonella Valenti, Alessandro Zanini, Clive Waddington, Germán Delibes, Elisa Guerra-Doce, Benjamin Neil, Marcus Brittain, Mike Luke, Richard Mortimer, Jocelyne Desideri, Marie Besse, Günter Brücken, Mirosław Furmanek, Agata Hałuszko, Maksym Mackiewicz, Artur Rapiński, Stephany Leach, Ignacio Soriano, Katina T. Lillios, João Luís Cardoso, Michael Parker Pearson, Piotr Włodarczak, T. Douglas Price, Pilar Prieto, Pierre-Jérôme Rey, Roberto Risch, Manuel A. Rojo Guerra, Aurore Schmitt, Joël Serralongue, Ana Maria Silva, Václav Smrčka, Luc Vergnaud, João Zilhão, David Caramelli, Thomas Higham, Mark G. Thomas, Douglas J. Kennett, Harry Fokkens, Volker Heyd, Alison Sheridan, Karl-Göran Sjögren, Philipp W. Stockhammer, Johannes Krause, Ron Pinhasi, Wolfgang Haak, Ian Barnes, Carles Lalueza-Fox, David Reich (2018) – The Beaker phenomenon and the genomic transformation of northwest Europe, Nature, 21 february 2018, doi:10.1038/nature25738

Abstract
From around 2750 to 2500 BC, Bell Beaker pottery became widespread across western and central Europe, before it disappeared between 2200 and 1800 BC. The forces that propelled its expansion are a matter of long-standing debate, and there is support for both cultural diffusion and migration having a role in this process. Here we present genome-wide data from 400 Neolithic, Copper Age and Bronze Age Europeans, including 226 individuals associated with Beaker-complex artefacts. We detected limited genetic affinity between Beaker-complex-associated individuals from Iberia and central Europe, and thus exclude migration as an important mechanism of spread between these two regions. However, migration had a key role in the further dissemination of the Beaker complex. We document this phenomenon most clearly in Britain, where the spread of the Beaker complex introduced high levels of steppe-related ancestry and was associated with the replacement of approximately 90% of Britain’s gene pool within a few hundred years, continuing the east-to-west expansion that had brought steppe-related ancestry into central and northern Europe over the previous centuries.

While the series of events that shaped the transition between foraging societies and food producers are well described for Central and Southern Europe, genetic evidence from Northern Europe surrounding the Baltic Sea is still sparse. Here, we report genome-wide DNA data from 38 ancient North Europeans ranging from ~9500 to 2200 years before present. Our analysis provides genetic evidence that hunter-gatherers settled Scandinavia via two routes. We reveal that the first Scandinavian farmers derive their ancestry from Anatolia 1000 years earlier than previously demonstrated. The range of Mesolithic Western hunter-gatherers extended to the east of the Baltic Sea, where these populations persisted without gene-flow from Central European farmers during the Early and Middle Neolithic. The arrival of steppe pastoralists in the Late Neolithic introduced a major shift in economy and mediated the spread of a new ancestry associated with the Corded Ware Complex in Northern Europe.

Human mobility has been vigorously debated as a key factor for the spread of bronze technology and profound changes in burial practices as well as material culture in central Europe at the transition from the Neolithic to the Bronze Age. However, the relevance of individual residential changes and their importance among specific age and sex groups are still poorly understood. Here, we present ancient DNA analysis, stable isotope data of oxygen, and radiogenic isotope ratios of strontium for 84 radiocarbon-dated skeletons from seven archaeological sites of the Late Neolithic Bell Beaker Complex and the Early Bronze Age from the Lech River valley in southern Bavaria, Germany. Complete mitochondrial genomes documented a diversification of maternal lineages over time. The isotope ratios disclosed the majority of the females to be nonlocal, while this is the case for only a few males and subadults. Most nonlocal females arrived in the study area as adults, but we do not detect their offspring among the sampled individuals. The striking patterns of patrilocality and female exogamy prevailed over at least 800 y between about 2500 and 1700 BC. The persisting residential rules and even a direct kinship relation across the transition from the Neolithic to the Bronze Age add to the archaeological evidence of continuing traditions from the Bell Beaker Complex to the Early Bronze Age. The results also attest to female mobility as a driving force for regional and supraregional communication and exchange at the dawn of the European metal ages.

The origins of the Bronze Age Minoan and Mycenaean cultures have puzzled archaeologists for more than a century. We have assembled genome-wide data from 19 ancient individuals, including Minoans from Crete, Mycenaeans from mainland Greece, and their eastern neighbours from southwestern Anatolia. Here we show that Minoans and Mycenaeans were genetically similar, having at least three-quarters of their ancestry from the first Neolithic farmers of western Anatolia and the Aegean, and most of the remainder from ancient populations related to those of the Caucasus and Iran. However, the Mycenaeans differed from Minoans in deriving additional ancestry from an ultimate source related to the hunter–gatherers of eastern Europe and Siberia, introduced via a proximal source related to the inhabitants of either the Eurasian steppe or Armenia. Modern Greeks resemble the Mycenaeans, but with some additional dilution of the Early Neolithic ancestry. Our results support the idea of continuity but not isolation in the history of populations of the Aegean, before and after the time of its earliest civilizations.

Farming was first introduced to southeastern Europe in the mid-7th millennium BCE - brought by migrants from Anatolia who settled in the region before spreading throughout Europe. However, the dynamics of the interaction between the first farmers and the indigenous hunter-gatherers remain poorly understood because of the near absence of ancient DNA from the region. We report new genome-wide ancient DNA data from 204 individuals-65 Paleolithic and Mesolithic, 93 Neolithic, and 46 Copper, Bronze and Iron Age-who lived in southeastern Europe and surrounding regions between about 12,000 and 500 BCE. We document that the hunter-gatherer populations of southeastern Europe, the Baltic, and the North Pontic Steppe were distinctive from those of western Europe, with a West-East cline of ancestry. We show that the people who brought farming to Europe were not part of a single population, as early farmers from southern Greece are not descended from the Neolithic population of northwestern Anatolia that was ancestral to all other European farmers. The ancestors of the first farmers of northern and western Europe passed through southeastern Europe with limited admixture with local hunter-gatherers, but we show that some groups that remained in the region mixed extensively with local hunter-gatherers, with relatively sex-balanced admixture compared to the male-biased hunter-gatherer admixture that we show prevailed later in the North and West. After the spread of farming, southeastern Europe continued to be a nexus between East and West, with intermittent steppe ancestry, including in individuals from the Varna I cemetery and associated with the Cucuteni-Trypillian archaeological complex, up to 2,000 years before the Steppe migration that replaced much of northern Europe's population.

Bell Beaker pottery spread across western and central Europe beginning around 2750 BCE before disappearing between 2200-1800 BCE. The mechanism of its expansion is a topic of long-standing debate, with support for both cultural diffusion and human migration. We present new genome-wide ancient DNA data from 170 Neolithic, Copper Age and Bronze Age Europeans, including 100 Beaker-associated individuals. In contrast to the Corded Ware Complex, which has previously been identified as arriving in central Europe following migration from the east, we observe limited genetic affinity between Iberian and central European Beaker Complex-associated individuals, and thus exclude migration as a significant mechanism of spread between these two regions. However, human migration did have an important role in the further dissemination of the Beaker Complex, which we document most clearly in Britain using data from 80 newly reported individuals dating to 3900-1200 BCE. British Neolithic farmers were genetically similar to contemporary populations in continental Europe and in particular to Neolithic Iberians, suggesting that a portion of the farmer ancestry in Britain came from the Mediterranean rather than the Danubian route of farming expansion. Beginning with the Beaker period, and continuing through the Bronze Age, all British individuals harboured high proportions of Steppe ancestry and were genetically closely related to Beaker-associated individuals from the Lower Rhine area. We use these observations to show that the spread of the Beaker Complex to Britain was mediated by migration from the continent that replaced >90% of Britain's Neolithic gene pool within a few hundred years, continuing the process that brought Steppe ancestry into central and northern Europe 400 years earlier.

Molecular signatures of Yersinia pestis were recently identified in prehistoric Eurasian individuals, thus suggesting Y. pestis might have caused some form of plague in humans prior to the first historically documented pandemic. Here, we present four new Y. pestis genomes from the European Late Neolithic and Bronze Age (LNBA) dating from 4,500 to 3,700 BP. We show that all currently investigated LNBA strains form a single genetic clade in the Y. pestis phylogeny that appears to be extinct today. Interpreting our data within the context of recent ancient human genomic evidence, which suggests an increase in human mobility during the LNBA, we propose a possible scenario for the spread of Y. pestis during the LNBA: Y. pestis may have entered Europe from Central Eurasia during an expansion of steppe pastoralists, possibly persisted within Europe until the mid Bronze Age, and moved back towards Central Eurasia in subsequent human population movements.

In the past decades ancient DNA research has brought numerous insights to archaeological research where traditional approaches were limited. The determination of sex in human skeletal remains is often challenging for physical anthropologists when dealing with incomplete , juvenile or pathological specimens. Molecular approaches allow sexing on the basis of sex-specific markers or by calculating the ratio of DNA derived from different chromosomes. Here we propose a novel approach that relies on the ratio of X chromosome-derived shotgun sequencing data to the autosomal coverage, thus establishing the probability of an XX or XY karyotype. Applying this approach to the individuals of the Upper Paleolithic triple burial of Dolní Věstonice reveals that all three skeletons, including the individual DV 15, whose sex has long been debated due to a pathological condition, were male.

How modern humans dispersed into Eurasia and Australasia, including the number of separate expansions and their timings, is highly debated [1, 2]. Two categories of models are proposed for the dispersal of non-Africans: (1) single dispersal, i.e., a single major diffusion of modern humans across Eurasia and Australasia [3-5]; and (2) multiple dispersal, i.e., additional earlier population expansions that may have contributed to the genetic diversity of some present-day humans outside of Africa [6-9]. Many variants of these models focus largely on Asia and Australasia, neglecting human dispersal into Europe, thus explaining only a subset of the entire colonization process outside of Africa [3-5, 8, 9]. The genetic diversity of the first modern humans who spread into Europe during the Late Pleistocene and the impact of subsequent climatic events on their demography are largely unknown. Here we analyze 55 complete human mitochondrial genomes (mtDNAs) of hunter-gatherers spanning ∼35,000 years of European prehistory. We unexpectedly find mtDNA lineage M in individuals prior to the Last Glacial Maximum (LGM). This lineage is absent in contemporary Europeans, although it is found at high frequency in modern Asians, Australasians, and Native Americans. Dating the most recent common ancestor of each of the modern non-African mtDNA clades reveals their single, late, and rapid dispersal less than 55,000 years ago. Demographic modeling not only indicates an LGM genetic bottleneck, but also provides surprising evidence of a major population turnover in Europe around 14,500 years ago during the Late Glacial, a period of climatic instability at the end of the Pleistocene.

Palaeogenetic investigations in three geographically close caves (Hohle Fels, Geißenklösterle, and Sirgenstein) in the Ach Valley near Blaubeuren (Swabian Jura) document the sudden replacement of Ursus spelaeus by Ursus ingressus around 28,000 14C BP. New radiocarbon dates suggest an earlier immigration of Ursus ingressus and at least a partial coexistence with Ursus spelaeus some 4500 years before the ultimate replacement. These two genetic types of cave bears used the same caves for hibernation and had the same herbivorous diet, as shown by the stable isotope results. In contrast, sympatric brown bears (Ursus arctos) exhibited a clearly different ecology, as shown by the carnivorous pattern of their isotopic signatures, and probably did not use the caves as dens before the Last Glacial Maximum (LGM).Once established, the younger cave bear (Ursus ingressus) remained the only cave bear for only another circa 2000 years after the last appearance of the classical cave bear (Ursus spelaeus) in the Ach Valley and elsewhere. The final appearance of cave bear (sensu lato) is now dated to 25,560 ± 130 BP, disproving a refuge area of this species in the Swabian Jura. After the extinction of cave bears (sensu lato), brown bears took over their cave dens and their nutritional niche as they shift to a diet dominated by plant food.

Recent ancient DNA studies have revealed that the genetic history of modern Europeans was shaped by a series of migration and admixture events between deeply diverged groups. While these events are well described in Central and Southern Europe, genetic evidence from Northern Europe surrounding the Baltic Sea is still sparse. Here we report genome-wide DNA data from 24 ancient North Europeans ranging from ~7,500 to 200 calBCE spanning the transition from a hunter-gatherer to an agricultural lifestyle, as well as the adoption of bronze metallurgy. We show that Scandinavia was settled after the retreat of the glacial ice sheets from a southern and a northern route, and that the first Scandinavian Neolithic farmers derive their ancestry from Anatolia 1000 years earlier than previously demonstrated. The range of Western European Mesolithic hunter-gatherers extended to the east of the Baltic Sea, where these populations persisted without gene-flow from Central European farmers until around 2,900 calBCE when the arrival of steppe pastoralists introduced a major