Ten millennia of hepatitis B virus evolution

[Figure: see text].

Ancient genomic time transect from the Central Asian Steppe unravels the history of the Scythians

The Scythians were a multitude of horse-warrior nomad cultures dwelling in the Eurasian steppe during the first millennium BCE. Because of the lack of first-hand written records, little is known about the origins and relations among the different cultures. To address these questions, we produced genome-wide data for 111 ancient individuals retrieved from 39 archaeological sites from the first millennia BCE and CE across the Central Asian Steppe. We uncovered major admixture events in the Late Bronze Age forming the genetic substratum for two main Iron Age gene-pools emerging around the Altai and the Urals respectively. Their demise was mirrored by new genetic turnovers, linked to the spread of the eastern nomad empires in the first centuries CE. Compared to the high genetic heterogeneity of the past, the homogenization of the present-day Kazakhs gene pool is notable, likely a result of 400 years of strict exogamous social rules.

New Data on the Holocene Mammal Fauna of the Ustyurt Plateau

Analysis of mammalian species composition has been performed for eight archaeological sites on the Ustyurt plateau. They date to the range from the middle Subboreal to the middle Subatlantic. The modern species composition of large mammals formed by the end of the Middle Holocene (Subboreal 2) and did not change until the early 20th century. The ungulate species composition and ratio on the plateau showed geographical variation and changed over time. Boars were always rare or absent in the north of Ustyurt. The structure of the ungulate fauna in the north of Ustyurt changed over time. Onager numbers in this area increased and saiga numbers decreased in the middle of the Late Holocene. Significant geographical differences in the structure of ungulate fauna were recorded in the middle of the Late Holocene. The numbers of onagers, goitered gazelles, and argali were higher, whereas the numbers of saigas were lower in the south of Ustyurt than in the north.

Ancient genomic changes associated with domestication of the horse

The domestication of the horse was a seminal event in human cultural evolution. Libradoet al.obtained genome sequences from 14 horses from the Bronze and Iron Ages, about 2000 to 4000 years ago, soon after domestication. They identified variants determining coat color and genes selected during the domestication process. They could also see evidence of admixture with archaic horses and the demography of the domestication process, which included the accumulation of deleterious variants. The horse appears to have undergone a different type of domestication process than animals that were domesticated simply for food.

Science, this issue p.442

Ancestry and demography and descendants of Iron Age nomads of the Eurasian Steppe

During the 1st millennium before the Common Era (BCE), nomadic tribes associated with the Iron Age Scythian culture spread over the Eurasian Steppe, covering a territory of more than 3,500 km in breadth. To understand the demographic processes behind the spread of the Scythian culture, we analysed genomic data from eight individuals and a mitochondrial dataset of 96 individuals originating in eastern and western parts of the Eurasian Steppe. Genomic inference reveals that Scythians in the east and the west of the steppe zone can best be described as a mixture of Yamnaya-related ancestry and an East Asian component. Demographic modelling suggests independent origins for eastern and western groups with ongoing gene-flow between them, plausibly explaining the striking uniformity of their material culture. We also find evidence that significant gene-flow from east to west Eurasia must have occurred early during the Iron Age.

New data on avifauna of the Ustyurt plateau in the Holocene

Bone remains of birds from a location of the middle Subboreal period and from three locations of the early Subatlantic period were studied on the Ustyurt plateau (Kazakhstan). Three out of 17 avian species that have been identified (Phalacrocorax pygmaeus, Falco peregrinus, and Nyctea scandiaca) proved to be absent in the modern fauna of the region. Our data on the bird fauna of the Ustyurt Plateau in the second half of the Middle Holocene and at the beginning of the Late Holocene indicate that, in that time, the migration routes of the little cormorant, peregrine, and snowy owl passed across the Ustyurt territory and the wintering sites of peregrine and snowy owl were more extensive and were also situated in Ustyurt. In the second half of the Late Holocene, the number of wintering sites of these species diminished and their migration routes have been altered.

Mitochondrial DNA analysis of horses recovered from a frozen tomb (Berel site, Kazakhstan, 3rd Century BC)

Sequence polymorphism of the mitochondrial DNA D-loop was used to determine the genetic diversity of horses recovered from a Scythian princely tomb dating from the beginning of the 3rd century BC. Eight haplotypes were found among the 13 ancient horse samples tested. Phylogenetical analysis showed that these ancient horse's sequences, along with two Yakut ones, were distributed throughout the tree defined by modern horses' sequences and are closely related to them. No clear geographical affiliation of the specimens studied was thus determined. Our work, among others, supports the very ancient origin of the matrilines in horses.

Genetic analysis of human remains from a double inhumation in a frozen kurgan in Kazakhstan (Berel site, Early 3rd Century BC)

The discovery of a big barrow of the Saka period in eastern Kazakhstan between the Russian and the Chinese borders provided the opportunity to excavate a frozen burial site. In the burial chamber, there was a wooden sarcophagus with two human bodies. The skeletons of these two individuals, a man and a woman, were well preserved. A genetic study based on STRs and mitochondrial DNA analyses was undertaken in order to determine whether these human remains belonged to close relatives. Results were obtained for all the markers. Nevertheless, nuclear STRs did not allow a clear conclusion concerning the relationship, but analysis of mitochondrial DNA showed that these skeletons were not close relatives.