The genetic prehistory of the Baltic Sea region

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.

. ADMIXTURE analysis of ancient and select modern individuals at k=11.
Basque  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Turkish  Ukraine_HG1 Ukraine_N1    Steppe

Supplementary Note 2 Archaeological context and sample description
This section provides archeological context for the 24 individuals for whom we report new genome-wide data, as well as the additional 81 human remains that were screened for this study. We also give a general overview of the prehistory of the Eastern Baltic and Scandinavian region as understood through archeology. Uncalibrated radiocarbon dates are in BP, calibrated radiocarbon dates are given at 94.5% confidence interval (calBCE), contextual archeological dating is given in BCE.The radiocarbon dates are not corrected for potential reservoir effects.
A tabular overview of information from all samples and their sequencing results is given in Supplementary Data Table 1.

The Eastern Baltic Region
Despite the similarities in the material culture and the smallness of the region, chronologies of the prehistory in the Baltic States varies, and to understand the context properly these have to be introduced first (Supplementary Table 8).

Supplementary Table 8. Chronology of prehistoric cultures in the Eastern Baltic region.
All dates given in BCE.
Despite the differences in the dates these chronologies highlight the following archaeologically visible turning points in the prehistory of the Eastern Baltic: (1) initial colonization of the region; (2) transition of subsistence relying on terrestrial mammals to the sea resources; (3) beginning of pottery production by huntergatherers; (4) influx of exotic resources; (5) introduction of farming and crop cultivation; and (6) introduction of first metal objects and metallurgy.
Initial colonization of the Eastern Baltic region occurred after the retreat of the ice sheets in the first half of the 9 th millennium BCE and following centuries. The pioneering settlers arrived from south and thus the first settlements are known from the territory of Southern-Lithuania and Latvia (already 11 000 BCE 6,9 ) whereas the northern shores of Estonia were inhabited a bit later. During ca. 9000-8500 BCE natural sources of flint, manufacturing techniques and analogous forms of bone and antler artefacts as well as similarities of lithic technologies point to the existence of extensive networks in the European Boreal zone 10 . From ca. 8000 BCE a transition from Paleolithic cultures to the Mesolithic Kunda Culture is seen. The name-giving site Kunda Lammasmägi was discovered already in 1870s during the marl mining 11 . The abundant bone material together with small items from mainly quartz hint on a variety of activities on the site 11,12 . The dominant species was elk 13 , while fish and seal bones appeared to be rare, indicating a subsistence dominated by terrestrial mammals 11,13 . In general, Kunda Culture, is characterized by inland camp sites on the shores of larger rivers and lakes, the main pray came from forests -being elk and beaver 9 and the flint technology aiming at using the all the available source material to produce flakes to make small items was prevalent 14 . At the second half of the Kunda period, during the 7 th millennium BCE the habitation spread to coast and further to the islands of the Baltic Sea 15 . During the Littorina Sea phase in the Baltic Sea basin hunting of marine mammals became important. From the beginning of the period there are no burial sites known; the earliest human remains -from the end of Kunda period -are known from the Zvejnieki cemetery in Northern Latvia 16,17 .
The beginning of pottery production at the region dates back to the 6 th millennium BCE being a cultural loan and an invention of hunter-gatherers. This period is named after the sites discovered in Narva area at the North-Eastern Estonia. As the successor of the Kunda Culture, the Narva Culture emerged around ca. 5500 BCE in the eastern inland Baltic region and spread north-, south and coastward in the following millennium, occupying the same region as the Kunda Culture 18 . In Estonia Narva Culture is distinguished only in the Late Mesolithic phase, whereas both in Latvia and Lithuania it continues to the Neolithic (Supplementary Note 1 Table 1). Despite this technological innovation of pottery production there were no marked changes in the life ways or usages of raw materials of hunter-gatherers in the Eastern Baltic region. Continuity with the Mesoltihic tradition is seen in production and use of bone and antler artefacts. Also continued is the subsistence strategy of foraging, and numerous finds show evidence fore reliance on fishing 19,20 . In Estonia the majority of the sites are located on the coast 2 and seal-hunting grew in importance, with presumably specialized seasonal sites for this puropose found on Estonian islands 21 . In the Middle Neolithic first sparse evidence is found in Narva sites for domesticated plants and animals but foraging ramins the dominant economy 20 . Assemblages of the Narva Culture persist in its southern occupational area until the Late Neolithic 7 .
The chronologically and geographically overlapping Combed Ware Culture of pottery producing hunter-gatherers to the north exhibited geographically extensive and intensive spread of foreign materials and artefacts, especially during Early Neolithic. On the territory of present-day Estonia flint, amber and metatuff from foreign sources were widely used. For example, flint is most likely from the upper reaches of the Volga River, but also from South Lithuania or Belarus. The origin of amber is difficult to detect, because the material and form are similar over an extensive area, most likely the amber came from Western Latvia and Western Lithuania. Metatuff used during the Stone Age on the territory of present day Estonia most likely came from the Onega region in Karelia in present day Russia; the most numerous artefact made of metatuff is the Russian-Karelian type of wood chopping tool 10 .
The process of Neolithization is different in the Eastern Baltic region from what is known in Central and Southern Europe, where the 'Neolithic package' is mostly defined by simultaneous emergence of pottery production, crop cultivation and herding of domesticated animals, sedentary life way, and monumental architecture. In the Eastern Baltic, it has been a long tradition that the pottery production solely defines the beginning of Neolithic, whereas the life ways of the people do not change that markedly. Recently, however, Kerkko Nordqvist and Aivar Kriiska have listed the characteristics of Neolithization in the region as the following 22 : • Pottery -great local variability of ceramics, which exhibit further a mixture of local traditions, domestic innovations, and external influences. Many new lines of development, like cultivation and rock art, appear roughly simultaneously with the adoption of pottery, even if these phenomena become more pronounced or visible only much later, especially around and after 4000 calBCE.
• From the 5th millennium calBCE onwards the material culture and the variety of raw materials become increasingly versatile. The broadening selection of mineral raw materials is especially striking. The working of stone materials and, consequently, the properties of artefacts start to change as well.
• The large-scale appearance of imported raw materials and artefacts is another novelty: carboniferous and cretaceous flint, particular slates and metatuffites as well as amber -and objects made of them. These materials and artefacts were transported in fairly large quantities and over distances of several hundreds, in some cases well over a thousand kilometres. Some artefact groups like wood-chopping tools of Russian-Karelian type or Baltic amber ornaments even indicate some sort of mass-or specialised production from the 4 th millennium calBCE onwards. The new exotic raw materials include also metal. The use of native copper started soon after 4000 calBCE in the Lake Onega region, from where it was also exported to Finland.
• Further, the formation or re-aligning of these contact or social networks and the changes they reflect or cause in the society are essential to the whole development discussed here. As mentioned above, the old 'borders', which derive from the Mesolithic remained visible after the adoption of pottery in the research area. However, the strong Neolithic impulse around 4000 calBCE, which can, for example, be mirrored against the distribution of Typical Comb Ware, transcends these borders and shows a significant change in the prevailing networks. After several centuries this situation was changing again.
Recent aDNA studies have resolved the long-lasting debate between the migrationists and diffusionists about the origins of Corded Ware/Battle Axe Culture in the Eastern Baltic 23 . It has been shown that these populations migrated to the region from the area of Yamnaya culture at the Russian steppe 2,24 . This took place during the first centuries of the 3rd millennium BCE. This migration also brought about the onset of food production as a regular form of substinence in all the present Baltic States 7,25 . However, the new way of life -agriculture -did not mean an end to the huntergatherer populations. These existed parallel in the Eastern Baltic region for a while 23,25 . Differently from the hunter-gatherer sites the occupation layers of Corded Ware sites were rather thin 9,23 . Moreover, Corded Ware people preferred to settle farther from the shores of water-bodies, neither were their habitation sites known from the coastal areas 23 . The culture is mostly defined by the abundant grave findsinhumations in flexed limbs and a specific set of grave goods comprising of battle axes and pottery -, and stray finds of boat shaped axes.
The beginning of Bronze Age in the Eastern Baltic is defined by the occurrence of the first bronze items, changes in the material culture in general, and the spread of bronze work. The earliest indications on the local bronze work in the region derive from Latvia and Lithuania around 2000 BCE 4 . The earliest bronze items show that Eastern Baltic tribes had contacts with different populations reaching from Scandinavia 26 to Russia 4 . Early Bronze Age has been seen as a transition period from Late Neolithic to the Late Bronze Age 4 . Despite the fact that many areas inhabited tensely during the Late Neolithic were abandoned and areas more appropriate for land cultivation were adopted during the Early Bronze Age, many previously known sites still remained settled; also stone tools still played a major role in the everyday life. Differently from Estonia EBA cemeteries are known both from Latvia (earth graves and barrows) and Lithuania (barrows) 4 .
The classical characteristics of Eastern Baltic Bronze Age become visible during the LBA. Some of the most significant antiquities from the LBA are the fortified settlements that are known from all three Baltic States (e.g. Iru, Asva, Kivutkalns, Vinakalns, Narkunai, Nevieriškes). Several families resided in these sites, it has been estimated that the typical community ranged between 30 to 50 members 4 . In addition to the EBA barrows known from Latvia and Lithuania there are also stone graves with above-ground constructions known from Estonia. These circular stone-cist graves are the most studied objects from the given period 4 . Also boat graves and earth graves are known from this period. For the first time in the Eastern Baltic prehistory we have marks on ancient field-systems (clearance cairn filed, block-shaped fields: Baltic and Celtic fields) that are well studied in Estonia 4 . These remarkable changes in material culture signify changes in the social structure and culture of the society. By the end of the period Eastern Baltic populations relied on economy fully focused on agriculture. These farming societies were characterized by stratified social structure developed ownership rights, rich material culture, and specific religious beliefs 4 .

Kõnnu, Estonia
Kõnnu is located on the present island of Saaremaa at the Kõnnu village (Pihtla parish). During its habitation it was a separate island in Litorina Sea a couple of kilometres south-east from the larger island of Saaremaa 27-31 ; according to analyses of the faunal material it has been argued to be a camp for seal hunting 13 . The settlement and burial site was discovered during gravel mining in the spring of 1977. The archaeological investigations lead by Lembit Jaanits took place in 1977 and 1978 (as the gravel mining continued documentation of the finds were carried out in 1979-1986). Most of the find material consisted of small quartz artefacts; amongst flint artefacts only scrapers were distinguished, also remarkable number of tooth pendants and various types of ceramics were found 27 .
The site is from Late Mesolithic and Early Neolithic, and is attributed to Kunda, Narva and Combed Ware Culture 25,27 . The skeletal remains of four individuals were found in graves I, II, and III, whereas grave II contained the remains of two individuals 27 . In addition to these single human bones were gathered from non-grave archaeological contexts 25 .
The biological sex and age at death estimations, and radiocarbon dates taken from Tõrv 25 .

Veibri quadruple burial, Estonia
The burial site is situated in south-eastern Estonia on a flood plain on the northern shore of the Suur Emajõgi River in the village of Veibri. The site was first discovered in 1997 and identified as a Corded Ware Culture and Medieval settlement site 32 ; in 2003 bones exposed above the ground were detected. During the excavations (lead by Kristiina Johanson, Mari Lõhmus (Tõrv) and Tõnno Jonuks) of human skeletal remains a quadruple grave was unearthed. The archaeothanatological analyses revealed that this is a multiple burial 25 , thus the deceased were buried simultaneously 25,33 ; no grave goods were found despite Narva-type pottery sherd close to skeleton III 34 .

Kivisaare, Estonia
Kivisaare settlement and burial site is located in the southern part of Estonia in Lalsi village, approximately 1.5 km from Põltsamaa River and 6 km from present shore of Lake Võrtsjärv 34 . Here, the human skeletal remains have been found occasionally since 1882 during gravel mining. The around 30 individuals found there makes it one of the largest burial grounds in the present-day Estonia 25  •

Naakamäe, Estonia
Naakamäe is a settlement and burial site in south-western part of Saaremaa island, and is attributed to the Typical and Late Combed Ware Culture 12,18 . The settlement site was excavated by Lembit Jaanits during 1958-1962; one burial was found at the edge of settlement area. The body was buried on its back with upper limbs slightly abducted at the shoulder, the latter being projected upwards, arms medially rotated, and forearms flexed at the elbow and pronated, the hands being slightly flexed on the wrist and rested in front of the abdomen; the lower extremities were both extended from the hip and knee 25 . Beneath the skull ochre was found, and a bone awl (AI 4022) was placed next to left body side 12 .
The biological sex and age at death estimation from Karin Mark's personal archive (TLU AI, F18) 42 , and radiocarbon date from Lõugas et al. (1996) 43 .

Kõljala, Estonia
Kõljala is a burial site in southern part of Saaremaa island. Three burials were unearthed at Kõljala by Richard Hausmann in 1901 (AI K35) 44 . Tooth pendants and slate ring ornaments made of metatuff were found with one skeleton. Based on the latter find the graves were dated to the second half of the 3 rd millennium 12 , and attributed to the Combed Ware Culture 25 .
The biological sex and age at death estimations, and radiocarbon dates after Tõrv 25 : Tamula I settlement and burial site is located in southeastern Estonia on the northeastern shore of Lake Tamula on a shallow cape Roosisaare, where Võhandu River joins the lake. The water level in Lake Tamula was lower during Stone Age than today therefore the cultural layer has been grown on the peat and sandmixed peat. Later the water level arose and the site was covered by lake 12 .
The skeletal remains of eight individuals were included to the study. The biological sex and age death estimations are given after Allmäe 47 ; burial descriptions after Lohmus 48 , Ots 46 , and Tõrv 25 the radiocarbon dates from Lõugas et al. 43 , Kriiska et al. 34 , Mannermaa 43 , and Tõrv 25 .
• Tamula XV, child ~1,5 yrs, buried on back, due to poor preservation the initial body position cannot be reconstructed entirely; grave goods present. No direct radiocarbon date.
• Tamula XVII, female 35-45 yrs, buried on back, with both upper and lower limbs in extension; grave goods present. No direct radiocarbon date.
• Tamula XX, male 25-35 yrs, buried on back, with both upper and lower limbs in extension; wooden branches; no grave goods. No direct radiocarbon date.

Ardu, Estonia
Ardu cemetery is situated in Northern Estonia in the village of Ardu, in the area of the upper reaches of the Pirita River, 100 meters from the river, on a gravel hill rising above the surrounding river plain 12,34 . The site was discovered during gravel mining. Two burials -Ardu I burial (AI 2745) in 1931 and Ardu II burial (AI 3499) in 1936 -were uncovered, both individuals buried in flexed position lying on left lateral side 49,50 . According to grave goods, for example Karlova-type battle-axe, bone adzes, flint adze, flint knives, bone awls, bone buttons, Corded Ware shreds etc., the burials are attributed to the Corded Ware Culture 12 .
• Ardu I, male adult. No direct radiocarbon dating.

Sope, Estonia
Sope burial site is situated at Soonurme village in North-Eastern Estonia, 4 km east of Purtse and 2 km south of Jabara village, on the lands of Metsavälja farmstead, on a small sandy knoll on the bank of the Sope Stream 12 .
Human skeletal remains and boat-shaped axes have been found since 1880s at Sope. The first proper archaeological excavations at Sope were conducted by Harri Moora 51 , who uncovered strongly flexed female skeleton (Sope I; AI 2607). In 1933 Richard Indreko uncovered second female skeleton (Sope II; AI 3175) with legs flexed at knees, lying on her right body side, right hand beneath her head and left hand lying in front of the the body 52 . Both graves contained grave goods: shell of freshwater pearl mussels, bone awls, ceramic vessel, and are attributed to the Corded Ware Culture 12,34 .
The biological sex and age at death are given after Karin Mark's personal archive (TLU AI, F18) 42 ; radiocarbon dates of from Kriiska et al. 34 and Lõugas et al. 43 and Rasmussen et al. 53 .

Kunila, Estonia
Kunila burial site is situated in Central Estonia, 4 km south-west of Puurmani on the western side of a small drumlin on Jaaniantsu Hill. The burial site was discovered in 1938, when stone axe and loose human bones were found during gravel mining. During the archaeological excavations in 1948 skeletal remains of two individuals were uncovered (AI 3723) 54 . Kunila burials had grave goods: in connection to Kunila I a stone adze and a battle-axe were found; in connection to Kunila II burial an adze of white flint and a grinding stone were obtained. The burials are attributed to Corded Ware Culture 12 .
The biological sex and age at death are given after Karin Mark's personal archive (TLU AI, F18) 40 ; radiocarbon date from Kriiska et al. 34 and Lõugas et al. 43 .
• Kunila I, male adult. No direct radiocarbon date.
• Kunila II, male adult (Poz-10825;3960±40BP, 2580-2340 calBCE) Valma, Estonia Valma is located in Central Estonia on the north-western shore of Lake Võrtsjärv, at the village Valma. The site was discovered in 1948, archaeological excavations lead by Lembit Jaanits were conducted in 1949, 1950, and 1953-1955. Although the majority of the settlement area was studied no other constructions than c. 10 hearths were found 55 . These allowed concluding that three to five contemporaneous dwellings must have been part of the settlement 18 . Also, six hearths with stone packing were found on the upper horizon of the cultural layer; these could either belong to the Typical Combed Ware or the Corded Ware Culture 18 or even to the Late Iron Age. The majority of the find material is Typical Combed Ware sherds 18,55 , but shards of Late Combed Ware and Corded Ware were also present. Also small stone tools from local flint were found 18,55 , and various kinds of adzes 18,55 .
From the periphery of the settlement area (NW part) two individuals -an adult male (III) and a young female (II) -were found 25 . These were adorned with grave goods 18,55 . Another grave with the remains of a child (I) in a depth of 115 cm from the topsoil was found on the SE part of the settlement. In this case only the skull and some other bones 12,18,55 were detected.
Due to the poor collagen preservation none of the three graves are dated 25 . Grave descriptions given after Tõrv 25 .
• Valma I, a child; partially preserved; without grave goods. No direct radiocarbon date.
• Valma II, an adult male; buried on back with both upper and lower limbs in extension; grave goods present. Probable collective burial, placed into the same grave with individual no. III. No direct radiocarbon date.
• Valma III, a young woman; buried on back with both upper and lower limbs in extension; grave goods present. Probable collective burial, placed into the same grave with individual no. II. No direct radiocarbon date.

Kääpa, Estonia
Kääpa is a settlement site located on the left bank of the Võhandu River, c. 5-10 km north-east of the Tamula settlement and burial site. The site was discovered in 1958 during the construction work of a bridge, and excavated in 1959-1962 and 1974 by Jaanits 56 . Similar to Tamula and Akali, the cultural layer at Kääpa is covered with peat, which indicates that during the habitation of the site, the water level at Võhandu River was lower than it is today. The find material is plentiful, being mostly represented by Narva Ware, but also Typical Combed Ware sherds have been found 56 . During the excavations in 1962, single human bones and cranial fragments were found from Kääpa.
• Kääpa I, an almost complete cranium with maxillary teeth of an adult individual are stored in the Archaeological Research Collections at the Tallinn University (AI 4245). No direct radiocarbon date.
Narva Joaorg, Estonia Narva Joaorg is located near the present town of Narva on the eastern border of Estonia of the western bank of the Narva River. The site was discovered in 1953 and in 1954 and 1957 Jaanits carried out preliminary surveys that were followed by extensive excavations in 1960 and 1962-1964. Narva Joaorg is a multi-layered and multi-cultural site consisting of three pre-ceramic Mesolithic layers and a Mesolithic/Early Neolithic layer with both Narva Ware and Typical Combed Ware present 12,18,57,58 . The oldest settlement layer was situated directly above the limestone bedrock. The radiocarbon dates from the Mesolithic layers date the site to c. 6600-4200 cal. BC, being the earliest known human occupation in the Narva-Luga region 59 .
The graves (AI 4264) comprise of loose, i.e. not fully articulated, human bones. No direct radiocarbon dates are available from human bone due to poor collagen preservation 25 : • Narva Joaorg I, probable male, adolescent, in the I Mesolithic layer, no grave goods. No direct radiocarbon date.
• Narva Joaorg II, an adult, in the II Mesolithic layer, no grave goods. No direct radiocarbon date.
• Narva Joaorg IV, an adult, in the III Mesolithic layer, grave goods. No direct radiocarbon date.

Biržai, Lithuania
The single burial site is located within the limits of the Biržai town in the northern part of Lithuania. Grave was originally placed at the edge of a steep and clayey bank (elevation up to 53 m a. s. l.) of the river Apaščia, some few hundred meters south from where it meets one of its tributaries -the river Agluona. In the 16 th c. the dam was built on the confluence of above-mentioned rivers, creating the artificial lake The site was discovered in 1978 when the area was being planted with forest. The same year archaeological excavations were started and continued for thirteen years (1978-1980, 1982-1985, 1991, 1994-1997, 1999, 2001). In 1980, six undisturbed graves dating to the Early -Middle Neolithic periods were uncovered in the low-lying and intermittently flooded periphery of dwelling area 8,171 . Uncovered graves themselves and their placement in the surrounding landscape arguably show signs of unusual burials.  This site is different from the others because it was discovered by professional archaeologists from the very beginning, which led to two years of excavations (1985 -1986

Plinkaigalis burial site
The burial site is located in the plains of central Lithuania on the eastern bank of the river Šušvė on the outskirts of the Plinkaigalis village, approximately 400 m south-east of an Iron age hill fort and settlement 66 . It is a relatively plane area, which is nevertheless distinguished from the surroundings by a low (up to 2 m height) moraine hill of sand and gravel (elevation up to 94 m a. s. l.).
The burial site was discovered in 1975 when local residents started digging for gravel in the western part of the hill. The same year site was granted a legal protection with archaeological excavations carried out for eight straight years in a row (1977)(1978)(1979)(1980)(1981)(1982)(1983)(1984).
During the eight years of fieldwork a total of 373 graves (364 inhumation and 9 cremation graves) with all but two of them dating to 3 rd to 8 th c. AD were uncovered 66  Turlojiškė archaeological complex, Lithuania The Turlojiškė archaeological complex is a group of settlement, burial, sacrificial, and other archaeological sites in a large, peaty area on the right bank of the river Kirsna in south-western part of Lithuania. The relief of this area is almost level, slightly undulating in places, with elevated areas in the northern and southern parts. The river Kirsna is in the western part of the area, the small Turlojiškė forest in the east, the grove Gojus located in the north on the grounds of the Jakimavičius family farmstead, and level cultivated fields in the south 68 . The first written record about archaeological finds from the area reached us from 1930 69 , in 1931 another paper was written on a human skull called "Kirsna man" 70 , which later turned out to be a skull of 35-40 year old male 71 .
A more precise location of the find spot of the aforementioned finds was not known until field surveys and excavations were conducted from 1995 to 2003. During the excavations 6 additional male graves were discovered and some of them were radiocarbon dated to Bronze age 8

Kivutkalns, Latvia
The Ķivutkalns hill-fort and cemetery was located on the island of Dole, on the lower course of the River Daugava, on a sandy spit of land formed by the former shore of the Daugava and the bed of a former river channel that is nowadays hard to distinguish. The Ķivutkalns site was totally excavated under the direction of Jānis Graudonis in 1966 and1967 in connection with the building of the Riga Hydroelectric Plant.
The site has been considered as the largest Late Bronze Age bronze-working centre in Latvia. One third of the archaeological artefacts found at Kivutkalns hill-fort in the lower Daugava river is related to bronze working 72  Combining the new animal bone data to old radiocarbon dates of charcoal provides supporting evidence for archaeological consensus date of the hill-fort usage during the first millennium BC. Five human bone collagen 14 C datings are surprisingly young and suggest that periods for cemetery and hill-fort usage were overlapping 74 .
The cultural layer, with a thickness of 1.6-3 m protected the cemetery from the harmful effects of the atmosphere and precipitation and in combination with the encasing of the burials in oak log it resulted in an exeptionnaly good preservation of the skeletons. All the burials in the cemetery were preserved (247 inhumations and 21 cremations) 75 .
For this work, all the studied individuals were radiocarbon dated and the results are given below (see also

Scandinavia
Archaeological finds show a human presence in Denmark and the south Swedish province of Skåne during the Lateglacial, when most of the Scandinavian peninsula still was covered by glaciers 77-80 . The ensuing Preboreal period saw a rapid colonization over large tracts of lands, with settlements established all along the coasts of Norway and West Sweden [81][82][83][84][85] , and also some sites known from Eastern and Northern Sweden as well as Northern Finland [86][87][88] . The Early Mesolithic archaeological assemblages differ between the South-West and the North-East, suggesting that groups with contrasting technological traditions entered the Scandinavian peninsula from different directions: One northern route through Finland that brought the post-Swiderian tradition, and a southern route through Denmark that brought the post-Ahrensburgian tradition 84,89,90 . It is also possible that humans crossed the Baltic by boat or on the sea ice of winter. Regional differences in material culture and technological traditions during the subsequent millennia of the Mesolithic 90-93 may partly be related to patterns that were already established during the colonization process, but may also be a result of later spread of traditions through social networks and/or resettling of groups of hunter-gatherers.
Around 4000 calBCE agriculture was introduced into South Scandinavia, along with a characteristic set of material culture known as the Funnel Beaker Culture (FBC or in the following TRB after the German term Trichterbecherkultur) [94][95][96][97][98][99] . There are a few examples of domesticates that pre-date this event, in the form of carbonised cereal grains, imprints of cereal grains in Mesolithic pottery and bones from domestic animals [98][99][100][101] , but it is only after 4000 calBCE that evidence of farming and cattle rearing becomes abundant in Denmark and South Sweden. Cattle was not only a source for meat, but was also used for dairy production 99,[103][104][105] . Material culture that can be considered part of the Funnel Beaker tradition also appear in South Norway, but here evidence of agriculture remain elusive or at best sporadic [106][107][108][109][110][111] . In the region of Denmark and South Sweden where agriculture do occur, it was practised along side hunting, gathering and fishing 94,95,99,103 .
In Southernmost Sweden, Denmark and adjacent Northern Germany pottery was produced locally already during the Mesolithic Ertebølle phase. The introduction of the TRB pottery tradition meant a change in technology and design that can be viewed as sudden or gradual depending on perspective 95,98,100,112,113 . In Central Sweden and Southern Norway TRB pottery was the first ceramic tradition to appear, and thus clearly have an origin outside of these regions 97,109 . The lithic industries tend to show a degree of continuity between the Late Mesolithic and Early Neolithic in most areas 96,110,114 . From a regional perspective, it is possible to distinguish TRB regions with specific designs and traditions that more or less mirror the geographic extent of Late Mesolithic traditions. This is also true on a pan-regional scale, where the Northern limit of the Scandinavian Funnel Beaker Culture coincide with the Northern limit of Late Mesolithic traditions 96,115 .
The nature of the transition to the Neolithic in Scandinavia has been debated since the birth of Scandinavian archaeology, and the change has variously been put down to migration or internal development 116 . During the last couple of decades two basic models has dominated the Scandinavian archaeology. One model sees the introduction of agriculture as a consequence of interaction, gift giving and intermarriage through social networks that connected foragers and farmers 95 The development was quite different in Eastern Central Sweden, where the settlement pattern shifted to the coast 123 . All known interior TRB settlements of an agricultural character were abandoned, and coastal sites previously used as seasonal camps for fishing and sealing were turned into more or less permanent settlements 96,123,124 .
While there are traces of small scale agriculture at several of these coastal localities (eg. carbonised cereal seeds) 125,126 , the bulk of the subsistence economy seem to have shifted towards marine resources like fish and seal 123,[125][126][127][128][129] . The economic change was accompanied by a change in material culture, particularly pottery design 123 . The archaeological assemblages from this phase are known as the Pitted Ware Culture (PWC). It should be emphasised that the change in material culture was gradual, and that the pottery of the first phase of the PWC retained the funnel-beaker shape, with changes mainly confined to the composition of the decoration, and the surface treatment of the vessels 123,124,132 .
The archaeological terminology with monikers like "Early Neolithic Funnel Beaker Culture", "Middle Neolithic Funnel Beaker Culture", and "Pitted Ware Culture" seem to imply continuity between the Early and Middle Neolithic TRB, and discontinuity between the EN TRB and PWC. However, it is important to recognise that this terminology was caused by research historical happenstance during the early 20 th century 125,132,133 . From the perspective of material culture, there is as much continuity between the EN TRB and the PWC, as between the Early and Middle Neolithic TRB.
The phase of the PWC that display a clear continuity with the preceding EN TRB, the Fagervik II stage, is primarily known from the former EN TRB areas of mainland and coastal archipelagos of Eastern Central Sweden 125,134 . The early PWC also appear in the regions immediately to the north of the EN TRB area, regions that were occupied by aceramic hunter-gatherers during the preceding phase (the latter groups are sometimes included under the term Slate Culture) 124,133,135 . This may be a territorial expansion of the EN TRB turning PWC, or local hunter-gatherers finally adopting the ceramic technology of their neighbours. An indication that the latter scenario may be right is the fact that there is a simultaneous transfer of technology going in the other direction: the use of the raw material slate for the production of polished arrow and spear points that become an important part of the PWC 124,136 .
During the following phases (Fagervik III, IV etc) the Pitted Ware phenomen spread over a larger area 137 , including the Baltic islands of Öland and Gotland (Sweden) and Åland (Finland). While the former two islands have traces of a TRB presence during the Early Neolithic, the Åland island had for millennia been settled by groups of hunter-gatherers of the Comb Ware tradition 91,138 . Stylistic borrowings from the Comb Ware tradition can be traced already in the EN TRB of Eastern Central Sweden, and the creation of the material culture of the PWC can be seen as the continuation of this process, with a blend of western and eastern ceramic traditions 123,124,133,139 . During the later phases of the PWC the funnel-beaker shape was abandoned and instead pots were designed with pointed bottoms, akin to East Baltic hunter-gatherer pottery.
From an archaeological point of view then, the Pitted Ware Culture could perhaps be seen as a mix of at least three components: The Early Neolithic Funnel Beaker Culture of Eastern Central Sweden, the Slate Culture of Dalarna and southern Norrland, and the Comb Ware Culture of Åland. It is likely that such a process also had consequences for the genetic composition of the resulting population.
Around 2800 calBCE -at the transition between Middle Neolithic A and Middle Neolithic B according to the Scandinavian terminology -a new set of material culture appear in the archaeological record of South Sweden and Norway, referred to as the Swedish-Norwegian Battle Axe Culture 119,123 . This is a regional version of the pan-European Corded Ware Culture (CWC). The Swedish CWC is represented by graves and -more rarely -settlement sites throughout South and Central Sweden, with a northern limit at the 60th parallell North. In the south Swedish province Skåne there are also palisade structures known 140 . In many regions the archaeological remains of the CWC replace or follow on the preceding MN TRB. This has variously been interpreted as the result of internal development, limited population movements or full scale migrations 122,139,141,142 . Recent research has stressed the similarities between the early phase of the Swedish CWC and the CWC of Finland, the Baltic Countries and northern Poland 122 .
In eastern South and Central Sweden the CWC appear alongside the Pitted Ware Culture 117,122 . While the latter have a clear association with the coast, due to the subsistence focus on fishing and sealing, the settlements and graves from the CWC are often found in the interior, without a direct association with water. The data on the subsistence of the CWC is sparse, but include domesticated animals, cereal crops and wild forest game 117,120,122,143 .
The northernmost provinces in Sweden with settlements and graves of the traditional CWC are Uppland and Västmanland in eastern Central Sweden. Most of Northern Sweden remained the territory of hunter-gatherers, but there also appear a small number of sites along the coast that contain archaeological material associated with the CWC 144 . These sites are of two types, one of which have been interpreted as the result of direct long distance (1500 km) colonization by CWC groups originating in South Scandinavia, the other type show a larger degree of continuity with the local hunter-gatherer traditions, but with with additions of cultivated plants and stylistic or technological borrowings that suggest contact with the CWC tradition.
The former category is best exemplified with a series of sites in Västerbotten, eg. Bjurselet, a settlement where close to 200 flint axes have been found, despite being located some 1500 km north of the nearest flint sources of South Scandinavia [144][145][146] . The lithic reduction done at Bjurselet suggest that the knappers where schooled in the technological tradition of South Scandinavia 145 . The other category is examplified by the sites Hedningahällan in Hälsingland and Bjästamon in Ångermanland [148][149][150] . These settlements contain lithic industries typical of the local hunter-gatherers eg. tools of slate and quartz, but in the case of Hedningahällan also fragmented CWC battle-axes, osteological assemblages dominated by seal and fish, but also finds of carbonised cereal seeds. The pottery is of a regional character, although with some stylistic traits reminiscent of Corded Ware 150 . The human crania from Ölsund, Forsa, Hälsingland discussed in the current paper has been found in the same region as the site Hedningahällan and date to the same phase 151 .

Kanaljorden, Motala, Sweden
Kanaljorden, Motala, is a Mesolithic settlement and ritual complex in the town of Motala, Östergötland, Sweden 86,152 . Motala cradles the outlet of the big lake Vättern into the river Motala Ström, which in turn discharge into the Baltic Sea. The site Kanaljorden (Motala parish ancient monument 187) is close to both river (100 m) and lake Vättern (300 m), but is situated on the rim and bottom of a separate wetland basin that constituted a small isolated lake during the time in question. Today the area is a peat bog, and is also covered by recent landfill and development.
The human remains that has been subjected to DNA-analysis where found on a man made 12 x 14 m stone-packing that had been constructed on the bottom of the small lake during the Mesolithic. The stone-packing was completely submerged and covered by at least 0,5 m of water at the time of use. The ritual depositions include human bones, mostly skulls and fragments of skulls of adults (21 finds) but also some stray postcranial bones from adults (10) as well as the bones of one infant. The latter find include bones from all parts of the body. The initial sampling for DNA of the Kanaljorden material was done before to the full osteological analysis to avoid DNA contamination. Each isolated find of a crania/crania fragment with part of the maxilla preserved, was numbered as individuals 1-9 during the sampling process, while the bones of the infant was numbered individual 10. A fragmentary find that was assigned as 11 during sampling, was retracted before analysis as the bones turned out to be non-human (was first believed to be fragments of a child crania). A disarticulated mandible was designated individual 12.
The osteological analysis that were done later calculated the MNI to ten based on the number of occipital bones, nine adults and one infant. This match the preliminary approximation based on the number of maxillas, although based on different bone elements 153 .
The DNA analysis of six of the crania and the mandible confirmed that each of these finds represents a unique individual 1 . Osteological observations and isotope analysis furthermore show that the mandible do not match any of the three remaining "individuals" from whom no DNA data are available 153,154 . Furthermore, considering the result of isotope analysis and overlap of bone elements, one fragmentary skull that lack a maxilla can be recognised as an additional individual, given the designation AA. In all this mean that a total of 12 individuals so far has been identified in the Kanaljorden assemblage (individuals 1-10, 12 and AA).
Two of the skulls were mounted on wooden stakes still embedded in the crania at the time of discovery, indicating that the skulls have been put on display prior to the deposition in to the lake. Beside human bones, the ritual depositions also include artefacts of antler, bone, wood and stone, animal carcasses/bones as well as nuts, mushrooms and berries. The fauna assemblage is dominated by bones from wild boar and brown bear, but also include elk (moose), red deer, roe deer, badger, beaver, pond turtle and pike. The depositions of artefacts include smooth bone points, barbed bone points, a bone point with flint inserts, antler pick axes and scrapers/knives made of wild boar tusk.
Direct dates on 18 human bones range between 7013 ± 76 and 6677 ± 31 BP, disregarding one outlier (7212 ± 109) which could not be confirmed by a duplicate date (6773 ± 30). Dates on animal bones (N=13) and tools made of bone and antler (7) range between 6935 ± 47 and 6611 ± 30 BP. The human samples may be affected by a moderate reservoir effect 154  The site Kvärlöv Kalkkälla (Saxtorp parish ancient monument 61), Skåne, Sweden is an offering-fen of the Funnel Beaker Culture (TRB), situated in the outskirts of the modern village Kvärlöv 155 . The fen is characterised as a spring mire, and is believed to have been rather shallow with varying water level. The material under consideration here date to the Scandinavian Early Neolithic (4000-3300 calBCE). During the Early Neolithic the spring mire was located on a gentle slope facing a narrow bay of the sea, some 50-100 m away, and 200 m from the mouth of the small river Kvärlövsån.
The Early Neolithic (EN) assemblage was found in a layer of sand mixed with fen peat. The find bearing EN layer has an extent of 350 m 2 , which gives a rough estimate of the extent of the wetland at this time 155,156 . The finds include 39 disarticulated human bones (0,7 kg). Three fragmentary crania are designated as numbered individuals 1, 2 and 3 in the osteological report, albeit with some reservation regarding the identification of Individual 3 in relation to Individual 2 155 . As the radiocarbon dates from these two finds are significantly different (Test statistic T 7.22, Xi2(.05) 3.84, degrees of freedom 1) they likely represent two different individuals. The remaining human bones may represent the same or additional individuals, seven of these have been included in the initial screening for aDNA.
Besides human bones, the spring mire also contained fragmented funnel-beaker pottery, knapped flint, hazelnut shells, raspberry seeds and animal bones. The fauna assemblage is dominated by domesticated species (cattle, sheep/goat and pig) but also include various wild animals as roe deer, red deer and seal. A dagger made of cattle bone has been 14 C-dated to the same period as the human remains (Ua-25501 4810±75), while bones from sheep/goat and pig are slightly younger and fall in the beginning of the Scandinavian Middle Neolithic (Ua-25499 4470±60, Ua-25500 4550±60) 151 .
There are two Early Neolithic TRB settlement sites in the immediate vicinity, the site Saxtorp (Saxtorp parish ancient monument 26), just 50 m North of the spring mire, and the settlement site Kvärlöv (Saxtorp parish ancient monument 23) 350 m to the South-East. The Early Neolithic phase at the Saxtorp settlement is represented by one singled ailed house, 19 x 6 m, and associated features and finds. The find material include funnel-beaker pottery, cereal seeds, hazelnut shells and knapped flint. 14 Cdates from features in the house indicate that it was in use during the later phase of the Early Neolithic. The settlement site Kvärlöv date to the first half of the Early Neolithic, and contain an oval post built house, 7,5 x 4,5 m, as well as two graves (skeletons not preserved) and features interpreted as wells or watering pits. The finds include fragmented funnel-beaker pottery, knapped flint, teeth from cattle, cereal seeds and a quernstone 97,155,157,158 .
• Saxtorp 462T, older adult. Ölsund, Hälsingland, Sweden The human cranium from Ölsund, Forsa parish, in Hälsingland is a stray find exposed by ditching of wetland forest 151 . The find-spot (Forsa parish ancient monument 416) is below the Stone Age sea level, the crania may be the remains of a drowned individual, or a person buried in the sea. Ölsund is located 20 km from the contemporary settlement site Hedningahällan, with an assemblage that show a mix of local hunter-gatherer tradition and CWC influences (cf. above). The crania belong to an individual between 28 and 45 years of age 159 . Compared to a modern skeleton, the features are robust, but less so than many males from Stone Age Scandinavia. There are some traits that point towards the identification of the cranium as female (tubera frontalia and occipitalia).

Northwest Russia
The first indications of settlement in the region of Karelia in the northwest of Russia and southwest of Finland date back to the Mesolithic, with the earliest find of a fishing net, radiocarbon dated to 9310±120 BP 160 .
This region is relevant to the peopling of Scandinavia after the retreat of the glacial ice sheets, as it lies on one of the proposed eastern routes of settlement 88 , which has also been suggested for the introduction of Saami-like groups 161 . Odentometric analyses suggested continuity between the Mesolithic population of Yuzhnyy Oleni Ostrov and present-day Saami 162 .
Yuzhnyy Oleni Ostrov, Karelia, Russia The Mesolithic site Yuzhnyy Oleni' Ostrov (Oleneostrovski' mogilnik or Deer Island cemetery), Onega Lake, Karelia, Russian Federation (61°30'N 35°45'E) was first discovered in the 1920s during quarrying activities, which unfortunately resulted in the destruction of large parts of the graveyard. Archaeological examination and professional excavation of the site by Soviet archaeologists in the 1930s and the 1950s eventually led to the discovery of 177 burials 163 , while the original size of the burial ground was estimated to have held up to 500 individuals 164 . The abundance and diversity of grave goods and various mortuary features render the Yuzhnyy Oleni Ostrov site exceptional among other Mesolithic sites in Europe. The site had first been identified as a Neolithic graveyard, but later reanalysis and radiocarbon dating revealed an age of around 7,700-7,300 uncalibrated years BP 165,166 . Skeletal remains and artifacts from this site are currently held at the Kunstkamera Museum, St Petersburg, Russia.
Co-analyzed with new data is the genome-wide data of UzOO-40 and UzOO-74 from this site which has been reported in previous studies 2 .
• UzOO77, female, 7,450-6,950 calBP, layer date based on associated individuals from the graveyard 165 Popovo, Archangelsk, Russia The Mesolithic site is located on the bank of the Kinema River, in the Archangelsk region (61°15′N 38°54′E). The dates obtained for this site range between 9,000-9,500 BP and 7,500-8,000 BP 167 and are expected to be revised to younger dates due to freshwater reservoir effects.