Genetic continuity of Indo-Iranian speakers since the Iron Age in southern Central Asia

Since prehistoric times, southern Central Asia has been at the crossroads of the movement of people, culture, and goods. Today, the Central Asian populations are divided into two cultural and linguistic groups: the Indo-Iranian and the Turko-Mongolian groups. Previous genetic studies unveiled that migrations from East Asia contributed to the spread of Turko-Mongolian populations in Central Asia and the partial replacement of the Indo-Iranian populations. However, little is known about the origin of the latters. To shed light on this, we compare the genetic data on two current-day Indo-Iranian populations — Yaghnobis and Tajiks — with genome-wide data from published ancient individuals. The present Indo-Iranian populations from Central Asia display a strong genetic continuity with Iron Age samples from Turkmenistan and Tajikistan. We model Yaghnobis as a mixture of 93% Iron Age individual from Turkmenistan and 7% from Baikal. For the Tajiks, we observe a higher Baikal ancestry and an additional admixture event with a South Asian population. Our results, therefore, suggest that in addition to a complex history, Central Asia shows a remarkable genetic continuity since the Iron Age, with only limited gene flow.

Genetic continuity of Indo-Iranian speakers since the Iron Age in southern Central Asia.

Since prehistoric times, South Central Asia has been at the crossroads of the movement of people, culture, and goods. Today, the Central Asia's populations are divided into two cultural and linguistic groups: the Indo-Iranian and the Turko-Mongolian groups. Previous genetic studies unveiled that migrations from East Asia contributed to the spread of Turko-Mongolian populations in Central Asia and the partial replacement of the Indo-Iranian population. However, little is known about the origin of the latter. To shed light on this, we compare the genetic data on two current-day populations - Yaghnobis and Tajiks - with genome-wide data from published ancient individuals. The present Indo-Iranian populations from Central Asia display a strong genetic continuity with Iron Age samples from Turkmenistan and Tajikistan. We model Yaghnobis as a mixture of 93% Iron Age individual from Turkmenistan and 7% from Baikal. For the Tajiks, we observe a higher Baikal ancestry and an additional admixture event with a South Asian population. Our results, therefore, suggest that in addition to a complex history, Central Asia shows a remarkable genetic continuity since the Iron Age, with only limited gene flow.

Reconstructing genetic histories and social organisation in Neolithic and Bronze Age Croatia

Ancient DNA studies have revealed how human migrations from the Neolithic to the Bronze Age transformed the social and genetic structure of European societies. Present-day Croatia lies at the heart of ancient migration routes through Europe, yet our knowledge about social and genetic processes here remains sparse. To shed light on these questions, we report new whole-genome data for 28 individuals dated to between ~ 4700 BCE–400 CE from two sites in present-day eastern Croatia. In the Middle Neolithic we evidence first cousin mating practices and strong genetic continuity from the Early Neolithic. In the Middle Bronze Age community that we studied, we find multiple closely related males suggesting a patrilocal social organisation. We also find in that community an unexpected genetic ancestry profile distinct from individuals found at contemporaneous sites in the region, due to the addition of hunter-gatherer-related ancestry. These findings support archaeological evidence for contacts with communities further north in the Carpathian Basin. Finally, an individual dated to Roman times exhibits an ancestry profile that is broadly present in the region today, adding an important data point to the substantial shift in ancestry that occurred in the region between the Bronze Age and today.

Does Shoot Apical Meristem Function as the Germline in Safeguarding Against Excess of Mutations?

A genetic continuity of living organisms relies on the germline which is a specialized cell lineage producing gametes. Essential in the germline functioning is the protection of genetic information that is subjected to spontaneous mutations. Due to indeterminate growth, late specification of the germline, and unique longevity, plants are expected to accumulate somatic mutations during their lifetime that leads to decrease in individual and population fitness. However, protective mechanisms, similar to those in animals, exist in plant shoot apical meristem (SAM) allowing plants to reduce the accumulation and transmission of mutations. This review describes cellular- and tissue-level mechanisms related to spatio-temporal distribution of cell divisions, organization of stem cell lineages, and cell fate specification to argue that the SAM functions analogous to animal germline.

Ancient Xinjiang mitogenomes reveal intense admixture with high genetic diversity

Xinjiang is a key region in northwestern China, connecting East and West Eurasian populations and cultures for thousands of years. To understand the genetic history of Xinjiang, we sequenced 237 complete ancient human mitochondrial genomes from the Bronze Age through Historical Era (41 archaeological sites). Overall, the Bronze Age Xinjiang populations show high diversity and regional genetic affinities with Steppe and northeastern Asian populations along with a deep ancient Siberian connection for the Tarim Basin Xiaohe individuals. In the Iron Age, in general, Steppe-related and northeastern Asian admixture intensified, with North and East Xinjiang populations showing more affinity with northeastern Asians and South Xinjiang populations showing more affinity with Central Asians. The genetic structure observed in the Historical Era of Xinjiang is similar to that in the Iron Age, demonstrating genetic continuity since the Iron Age with some additional genetic admixture with populations surrounding the Xinjiang region.

Population dynamics in the Japanese Archipelago since the Pleistocene

The Japanese Archipelago is widely covered with acidic soil made of volcanic ash, an environment which is detrimental to the preservation of ancient biomolecules. More than 10,000 Palaeolithic and Neolithic sites have been discovered nationwide, but few skeletal remains exist and preservation of DNA is poor. Despite these challenging circumstances, we succeeded in obtaining a complete mitogenome sequence from Palaeolithic human remains. We also obtained those of Neolithic (hunting-gathering Jomon and the farming Yayoi cultures) remains, and over 2,000 present-day Japanese. The Palaeolithic mitogenome is potentially an ancestral type of haplogroup M, suggesting it is not only connected to present-day Japanese but also present-day East Asians. There were no changes in the gene pool from the hunting-gathering (Jomon) to the farming cultures (Yayoi), and this is different from in Europe, where there was no genetic continuity between hunter-gatherers and farmers. We also found that a vast increase of population size happened and has continued since the Yayoi period, characterized with paddy rice farming. It means that the cultural transition, i.e. rice agriculture, had significant impact on the demographic history of Japanese population.

Bluetongue virus in South America: current status based on phylogenetic analysis

Bluetongue (BT) is an insect-borne disease affecting domestic and wild ruminants. Bluetongue virus (BTV) is the causative agent of the BT disease. BT outbreaks have been widely recorded worldwide. However, in the South American subcontinent, accurate information about the disease and molecular epidemiology is still lacking because little effort has been made to cover the region. This study comprises an exhaustive phylogenetic analysis including all BTV sequences available in databases and reports new Argentinean sequences for Seg 8 and Seg 9. Maximum-likelihood phylogenetic analyses were conducted for Seg 2, Seg 3, Seg 6, Seg 7, Seg 8, Seg 9 and Seg 10. Throughout the study, wide circulation and genetic continuity along the American continent were detected. Also, reassortment events are reported, and the historical virus introduction path into and through South America is suggested.

Andronovo Problem: Studies of Cultural Genesis in the Eurasian Bronze Age

Andronovo culture is the largest Eurasian formation in the Bronze Age, and it had a significant impact on neighboring regions. It is the important culture for understanding many historical processes, in particular, the origins and migration of Indo-Europeans. However, in most works there is a very simplified understanding of the scientific problems associated with this culture. The history of its study is full of opposing opinions, and all these opinions were based on reliable grounds. For a long time, the existence of the Andronovo problem was caused by the fact that researchers supposed they might explain general processes by local situations. In fact, the term “Andronovo culture” is incorrect. Another term “Andronovo cultural-historical commonality” also has no signs of scientific terminology. Under these terms a large number of cultures are combined, many of which were not related to each other. In the most simplified form, they can be combined into two blocks that existed during the Bronze Age: the steppe (Sintashta, Petrovka, Alakul, Sargari) and the forest-steppe (Fyodorovka, Cherkaskul, Mezhovka). Often these cultures are placed in vertical lines with genetic continuity. However, the problems of their chronology and interaction are very complicated. By Andronovo cultures we may understand only Fyodorovka and Alakul cultures (except for its early stage); however, it is better to avoid the use of this term.

Gravettian cranial morphology and human group affinities during the European Upper Palaeolithic

Archaeologically defined Upper Palaeolithic (UP, 45,000–10,000 years ago) “cultures” are often used as proxies to designate fossil populations. While recent genomic studies have partly clarified the complex relationship between European UP “cultures” and past population dynamics, they leave open numerous questions regarding the biological characterization of these human groups, especially regarding the Mid-UP period (MUP, 33,000–24,000 years ago), which encompasses a pan-European cultural mosaic (Gravettian) with several regional facies. Here, we analyse a large database of well-dated and well-preserved UP crania, including MUP specimens from South-West France (SWF) and Moravia, using 3D geometric morphometrics to test for human group affinities. Our results show that the Gravettian makers from these two regions form a remarkably phenetically homogeneous sample which is different from, and more homogeneous than, the Late UP sample. Those results are congruent with genomic studies indicating a genetic continuity within the Gravettian manufacturers and a discontinuity marked by the Last Glacial Maximum (LGM). Moreover, our study expands the geographical range of the MUP phenetic continuity to SWF, for which aDNA data are scarce, and clarifies the post-LGM European population structure in SWF, with a possible dual ancestry stemming from different LGM refugia.

Early medieval genetic data from Ural region evaluated in the light of archaeological evidence of ancient Hungarians

The ancient Hungarians originated from the Ural region of Russia, and migrated through the Middle-Volga region and the Eastern European steppe into the Carpathian Basin during the ninth century AD. Their Homeland was probably in the southern Trans-Ural region, where the Kushnarenkovo culture was disseminated. In the Cis-Ural region Lomovatovo and Nevolino cultures are archaeologically related to ancient Hungarians. In this study we describe maternal and paternal lineages of 36 individuals from these regions and nine Hungarian Conquest period individuals from today’s Hungary, as well as shallow shotgun genome data from the Trans-Uralic Uyelgi cemetery. We point out the genetic continuity between the three chronological horizons of Uyelgi cemetery, which was a burial place of a rather endogamous population. Using phylogenetic and population genetic analyses we demonstrate the genetic connection between Trans-, Cis-Ural and the Carpathian Basin on various levels. The analyses of this new Uralic dataset fill a gap of population genetic research of Eurasia, and reshape the conclusions previously drawn from tenth to eleventh century ancient mitogenomes and Y-chromosomes from Hungary.