30,173 research outputs found
HOW EUROPEAN HISTORIANS IN THE NINETEENTH AND EARLY TWENTIETH CENTURIES TOLD THE HISTORY OF HUMAN MASS MIGRATIONS OR VĂLKERWANDERUNGEN
Historiansâ interest in the history of human migrations is not limited to recent years. Migrations had already figured as explanatory factors in connection with cultural and historical change in the work of classical and ancient studies scholars of the late nineteenth and early twentieth centuries. In the writings of these scholars, migrations acted as historical landmarks or epochal thresholds and played a key role in the construction of geoâhistorical areas. This model has been called âmigrationismâ and cannot be explained simply on the basis of the history of individual disciplines, but must be seen in its complex interaction with scientific and historical contexts. However, âmigrationismâ does not relate to fixed political and scientific positions or movements. For this reason, it cannot be explained adequately by using a historically or ideologically based approach. Relying on narratological approaches, this article examines migration narratives that historians of this period used to explain the rise and fall of ancient civilizations. Referring to contemporary historiographical representations of the ancient Near East, it distinguishes three main narratives that are still common today: narratives of foundation, narratives of destruction, and narratives of mixtures. In this sense, analyzing older migration narratives helps us to sharpen the critical view on the genealogy of our own views on the historyâand presentâof human migrations
Interrogation of modern and ancient genomes reveals the complex domestic history of cattle
The analysis of mitochondrial and nuclear DNA sequence polymorphisms from modern cattle populations has had a profound impact on our understanding of the events surrounding the domestication of cattle. From these studies, it has been possible to distinguish between pre- and post-domestic genetic differentiation, supporting previous assertions from archaeological studies and, in some cases, revealing novel aspects of the demographic history of cattle.
Analyses of genetic material retrieved from the remains of extinct ancestral wild cattle have also added valuable layers of information pertaining to cattle domestic origins; however, information from these investigations have, in general, been limited to small, variable portions of the mitochondrial genome owing to technical challenges associated with the retrieval and amplification of ancient DNA.
In recent years, however, new high-throughput, massively parallel genomics technology platforms, such as single-nucleotide polymorphism (SNP) genotyping arrays and next-generation sequencing (NGS), have provided a new impetus to the studies of genetic variation in extant and ancient cattle.
Arrays of SNP have facilitated high-resolution genetic surveys of global cattle populations and detection of ancient and recent genomic selective sweeps. Next-generation sequencing analyses of modern and ancient cattle hold great promise for identifying and cataloging of pre- and post-domestication patterns of genomic variation and correlating this with natural and artificial selection processes
Genetic Stratigraphy of Key Demographic Events in Arabia
The issue of admixture in human populations is normally addressed by genome-wide (GW) studies, and several approaches have been developed to date admixture events [1,2,3,4,5]. Admixed populations bear chromosomes with segments of DNA from all contributing source groups, the size of which decreases over successive generations until recombination renders them undetectably short. Several algorithms attempt to date admixture events by inferring the size of the nuclear ancestry segments, and these can work well when dating recent episodes in human history, such as the sub-Saharan African input into the New World [6], but they fail to detect several known episodes that took place at earlier times, such as the African input into Iberia [1] and genetic exchanges across the Red Sea [7]. Simulations with the suite of methods available at the ADMIXTOOLS package indicated that these methods could detect admixture events as early as 500 generation ago, but real data did not allow the tracing of such old events [8]. A recent improved algorithm, called GLOBETROTTER, has been used to tackle the detection of the co-occurrence of several mixture events by decomposing each chromosome into a series of haplotypic chunks and then analysing each chunk independently [3], but the problem of detecting ancient events remains. Its application to the systematic screening of worldwide admixture events was able to reveal around 100 events, but all occurring over only the past 4,000 years [3
Meta-Analysis of Mitochondrial DNA Reveals Several Population Bottlenecks during Worldwide Migrations of Cattle
Several studies have investigated the differentiation of mitochondrial DNA in Eurasian, African and American cattle as well as archaeological bovine material. A global survey of these studies shows that haplogroup distributions are more stable in time than in space. All major migrations of cattle have shifted the haplogroup distributions considerably with a reduction of the number of haplogroups and/or an expansion of haplotypes that are rare or absent in the ancestral populations. The most extreme case is the almost exclusive colonization of Africa by the T1 haplogroup, which is rare in Southwest Asian cattle. In contrast, ancient samples invariably show continuity with present-day cattle from the same location. These findings indicate strong maternal founder effects followed by limited maternal gene flow when new territories are colonized. However, effects of adaptation to new environments may also play a rol
The Missing Link of Jewish European Ancestry: Contrasting the Rhineland and the Khazarian Hypotheses
The question of Jewish ancestry has been the subject of controversy for over
two centuries and has yet to be resolved. The "Rhineland Hypothesis" proposes
that Eastern European Jews emerged from a small group of German Jews who
migrated eastward and expanded rapidly. Alternatively, the "Khazarian
Hypothesis" suggests that Eastern European descended from Judean tribes who
joined the Khazars, an amalgam of Turkic clans that settled the Caucasus in the
early centuries CE and converted to Judaism in the 8th century. The Judaized
Empire was continuously reinforced with Mesopotamian and Greco-Roman Jews until
the 13th century. Following the collapse of their empire, the Judeo-Khazars
fled to Eastern Europe. The rise of European Jewry is therefore explained by
the contribution of the Judeo-Khazars. Thus far, however, their contribution
has been estimated only empirically; the absence of genome-wide data from
Caucasus populations precluded testing the Khazarian Hypothesis. Recent
sequencing of modern Caucasus populations prompted us to revisit the Khazarian
Hypothesis and compare it with the Rhineland Hypothesis. We applied a wide
range of population genetic analyses - including principal component,
biogeographical origin, admixture, identity by descent, allele sharing
distance, and uniparental analyses - to compare these two hypotheses. Our
findings support the Khazarian Hypothesis and portray the European Jewish
genome as a mosaic of Caucasus, European, and Semitic ancestries, thereby
consolidating previous contradictory reports of Jewish ancestry.Comment: 21 pages, 7 figures, 1 table, 7 supplementary figures, 7
supplementary table
Resolving the ancestry of Austronesian-speaking populations
There are two very different interpretations of the prehistory of Island Southeast Asia (ISEA), with genetic evidence invoked in support of both. The âout-of-Taiwanâ model proposes a major Late Holocene expansion of Neolithic Austronesian speakers from Taiwan. An alternative, proposing that Late Glacial/postglacial sea-level rises triggered largely autochthonous dispersals, accounts for some otherwise enigmatic genetic patterns, but fails to explain the Austronesian language dispersal. Combining mitochondrial DNA (mtDNA), Y-chromosome and genome-wide data, we performed the most comprehensive analysis of the region to date, obtaining highly consistent results across all three systems and allowing us to reconcile the models. We infer a primarily common ancestry for Taiwan/ISEA populations established before the Neolithic, but also detected clear signals of two minor Late Holocene migrations, probably representing Neolithic input from both Mainland Southeast Asia and South China, via Taiwan. This latter may therefore have mediated the Austronesian language dispersal, implying small-scale migration and language shift rather than large-scale expansion
Adhuc Tacfarinas: the causes of the Tiberian war in North Africa (AD ca. 15-24) and the impact of the conflict on Roman imperial policy
During the reign of Tiberius successive governors of Africa Proconsularis struggled to suppress a serious revolt by a number of semi-nomadic tribes led by Tacfarinas. The conflict can only be explained convincingly as an indigenous act of negative negotiation of the Roman administrative encroachment on tribal territory. An in-depth analysis of the literary, epigraphic and archaeological evidence, as well as modern migration patterns, indicates that the rebellion should be perceived as the outcome of cadastral activities, which entailed taxation and confiscations. The actual causes of this rebellion do not support the traditional view of antagonism between agriculturalist and pastoralist communities in North Africa
Quantifying the legacy of the Chinese Neolithic on the maternal genetic heritage of Taiwan and Island Southeast Asia
There has been a long-standing debate concerning the extent to which the spread of Neolithic ceramics and Malay-Polynesian languages in Island Southeast Asia (ISEA) were coupled to an agriculturally driven demic dispersal out of Taiwan 4000 years ago (4 ka). We previously addressed this question using founder analysis of mitochondrial DNA (mtDNA) control-region sequences to identify major lineage clusters most likely to have dispersed from Taiwan into ISEA, proposing that the dispersal had a relatively minor impact on the extant genetic structure of ISEA, and that the role of agriculture in the expansion of the Austronesian languages was therefore likely to have been correspondingly minor. Here we test these conclusions by sequencing whole mtDNAs from across Taiwan and ISEA, using their higher chronological precision to resolve the overall proportion that participated in the âout-of-Taiwanâ mid-Holocene dispersal as opposed to earlier, postglacial expansions in the Early Holocene. We show that, in total, about 20 % of mtDNA lineages in the modern ISEA pool result from the âout-of-Taiwanâ dispersal, with most of the remainder signifying earlier processes, mainly due to sea-level rises after the Last Glacial Maximum. Notably, we show that every one of these founder clusters previously entered Taiwan from China, 6â7 ka, where rice-farming originated, and remained distinct from the indigenous Taiwanese population until after the subsequent dispersal into ISEA
Massive migration from the steppe is a source for Indo-European languages in Europe
We generated genome-wide data from 69 Europeans who lived between 8,000-3,000
years ago by enriching ancient DNA libraries for a target set of almost four
hundred thousand polymorphisms. Enrichment of these positions decreases the
sequencing required for genome-wide ancient DNA analysis by a median of around
250-fold, allowing us to study an order of magnitude more individuals than
previous studies and to obtain new insights about the past. We show that the
populations of western and far eastern Europe followed opposite trajectories
between 8,000-5,000 years ago. At the beginning of the Neolithic period in
Europe, ~8,000-7,000 years ago, closely related groups of early farmers
appeared in Germany, Hungary, and Spain, different from indigenous
hunter-gatherers, whereas Russia was inhabited by a distinctive population of
hunter-gatherers with high affinity to a ~24,000 year old Siberian6 . By
~6,000-5,000 years ago, a resurgence of hunter-gatherer ancestry had occurred
throughout much of Europe, but in Russia, the Yamnaya steppe herders of this
time were descended not only from the preceding eastern European
hunter-gatherers, but from a population of Near Eastern ancestry. Western and
Eastern Europe came into contact ~4,500 years ago, as the Late Neolithic Corded
Ware people from Germany traced ~3/4 of their ancestry to the Yamnaya,
documenting a massive migration into the heartland of Europe from its eastern
periphery. This steppe ancestry persisted in all sampled central Europeans
until at least ~3,000 years ago, and is ubiquitous in present-day Europeans.
These results provide support for the theory of a steppe origin of at least
some of the Indo-European languages of Europe
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