Er moderne skandinaviske kvinner etterkommere av de første jorbrukere fra traktbegerkulturen?

trbDienekes: Coming shortly after Bramanti et al. (2009) which discovered a discontinuity between Neolithic farmers from Central and Eastern Europe and the pre-existing hunter-gatherers, a new study examines ancient DNA from northern European populations, extending the picture of discontinuity all the way to Scandinavia. This is one more nail in the coffin of the cultural diffusion hypothesis, and in favor for a demic diffusion of agriculture all the way to the northernmost reaches of Europe.

More on this after I read the full paper.

UPDATE (Sep 25):

From the paper:

Although the hunter-gatherers of Denmark and southern Sweden adopted pottery early on, the Neolithization first took real shape with the appearance of the Funnel Beaker Cultural complex (FBC, also known as the Trichterbecher Kultur [TRB]) some 6,000 years BP (the oldest evidence possible dating back some 6,200 years BP [9]). Atthis time domestic cattle and sheep, cereal cultivation, and the characteristic TRB pottery were introduced into most of Denmark and southern parts of Sweden [6]. Nevertheless,the Neolithization process was slow in Scandinavia, and large are as remained populated by hunter-gatherer groups until the end of the 5th millennium BP.

One of these last hunter-gatherer complexes was the Pitted Ware culture (PWC), which can be identified by its single-inhumation graves distributed over the coastal areas of Sweden and the Baltic Sea islands that lie closest to the Swedish coast. Intriguingly, the PWC first appears in the archaeological record of Scandinavia after the arrival of the TRB (some 5,300 yearsBP) and existed in parallel with farmers for more than a millennium before vanishing about 4,000 years BP .

The authors sampled 3 TRB individuals from «one passage tomb, Gokhem, dated to 5,500–4,500 years BP» which were found to belong to haplogroups H, J, and T, and 19 PWC individuals «from three different sites on the Baltic island of Gotland dated to 4,800–4,000 years BP» which were found to belong to haplogroups J, T, V (one each), «Other» (two), U5 and U5a (three each), and U4/H1b (eight samples).

From the paper:

Given our results, it remains possible that the PWC represent remnants of a larger northern European Mesolithic hunter gather complex. However, it appears unlikely that population continuity exists between the PWC and contemporary Scandinavians or Saami. Thus, our findings are in agreement with archaeological theories suggesting Neolithic or post-Neolithic population introgression or replacement in Scandinavia. To what extent this holds true for other parts of Europe requires further direct testing, although morphological [24, 25], ancient [26], and modern [4, 5] genetic data suggest that this is probably the case.

The results indicate that the PWC was dominated by haplogroup U (about three quarters of the mtDNA gene pool). The inability to resolve between U4 and H1b is due to the portion of the mtDNA sampled. Given (i) the absence of other H subgroups in the large sample, (ii) the higher frequency of U4 in modern populations, (iii) the presence of U4 but not H1b in other pre-farming populations of Europe (after Bramanti et al.), (iv) the absence of U4 in Neolithic populations, (v) the higher coalescence age of U4 compared to H1b, suggesting a deeper ancestry, I am inclined to think that most, if not all of the U4/H1b is actually just U4.

UPDATE II:

Fst between the PWC and modern populations ranged between 0.036 (Latvians) and Saami (0.25). For Swedes and Norwegians they were 0.051 and 0.061. A few conclusions can be drawn from this:

1. The notion of Saami as unmixed descendants of pre-farming Europeans is debunked.
2. Latvians and other populations of the eastern Baltic are the closest (although by no means very close) to the PWC.
3. Swedes and Norwegians are somewhat closer to the pre-farming inhabitants than is the case for Central Europe where Fst=0.086 was estimated by Bramanti et al. (2009)

Traditional physical anthropology held that there were three main elements in northern Europe, which have been given different names, but can be summarized as follows:

1. Narrow- and high-faced populations, a new element in the region, similar to that of Central Europe
2. Broad-faced massive Proto-Europoid populations, the aboriginal inhabitants of northern and eastern Europe
3. Flat-nosed populations with eastern affiliations

To quote Raisa Denisova:

Latvia’s most ancient inhabitants tended to be large in size, with large skulls, a distinctly oblong head shape, a broad, high face and a distinctly protruding nose (Denisova 1975). Looking at this data in the context of synchronous populations elsewhere in Europe, we can find specific geographic differentials. This is especially true of the facial width of residents, a factor which has great weight in the specification of race (Denisova 1978). Differences in facial width in Europe became particularly distinctive at the beginning of the Atlantic period, when farming was begun in Europe. At this time, facial width distinctly separated morphological forms in Northern Europe from those in the Mediterranean region — two distinct geographic regions. Massive, broad-faced morphological forms dominated in northern and northeastern Europe, while gracile, narrow-faced forms are found most often in Middle Europe and the continent’s southeastern reaches. During the Atlantic period, narrow-faced populations gradually moved in the northerly and northeasterly direction. They reached the Baltic region only during the Bronze Age. For this reason, during the Mesolithic and Neolithic period, people in the Baltic region (and surrounding regions) had broad faces, a fact which affirms their links to the late Paleolithic populations of Europe.

Modern Scandinavians are more (1) than (2), while modern Balts are more (2) than (1). The mtDNA picture seems fairly consistent with a greater persistence of Proto-Europoid elements among the Balts.

A related public release:

Scandinavians are descended from Stone Age immigrants

Today’s Scandinavians are not descended from the people who came to Scandinavia at the conclusion of the last ice age but, apparently, from a population that arrived later, concurrently with the introduction of agriculture. This is one conclusion of a new study straddling the borderline between genetics and archaeology, which involved Swedish researchers and which has now been published in the journal Current Biology.

«The hunter-gatherers who inhabited Scandinavia more than 4,000 years ago had a different gene pool than ours,» explains Anders Götherström of the Department of Evolutionary Biology at Uppsala University, who headed the project together with Eske Willerslev of the Centre for GeoGenetics at the University of Copenhagen.

The study, a collaboration among research groups in Sweden, Denmark and the UK, involved using DNA from Stone Age remains to investigate whether the practices of cultivating crops and keeping livestock were spread by immigrants or represented innovations on the part of hunter-gatherers.

«Obtaining reliable results from DNA from such ancient human remains involves very complicated work,» says Helena Malmström of the Department of Evolutionary Biology at Uppsala University.

She carried out the initial DNA sequencings of Stone Age material three years ago. Significant time was then required for researchers to confirm that the material really was thousands of years old.

«This is a classic issue within archaeology,» says Petra Molnar at the Osteoarchaeological Research Laboratory at Stockholm University. «Our findings show that today’s Scandinavians are not the direct descendants of the hunter-gatherers who lived in the region during the Stone Age. This entails the conclusion that some form of migration to Scandinavia took place, probably at the onset of the agricultural Stone Age. The extent of this migration is as of yet impossible to determine.»

Current Biology doi:10.1016/j.cub.2009.09.017

Ancient DNA Reveals Lack of Continuity between Neolithic Hunter-Gatherers and Contemporary Scandinavians

Helena Malmström et al.

Abstract

The driving force behind the transition from a foraging to a farming lifestyle in prehistoric Europe (Neolithization) has been debated for more than a century [1], [2] and [3]. Of particular interest is whether population replacement or cultural exchange was responsible [3], [4] and [5]. Scandinavia holds a unique place in this debate, for it maintained one of the last major hunter-gatherer complexes in Neolithic Europe, the Pitted Ware culture [6]. Intriguingly, these late hunter-gatherers existed in parallel to early farmers for more than a millennium before they vanished some 4,000 years ago [7] and [8]. The prolonged coexistence of the two cultures in Scandinavia has been cited as an argument against population replacement between the Mesolithic and the present [7] and [8]. Through analysis of DNA extracted from ancient Scandinavian human remains, we show that people of the Pitted Ware culture were not the direct ancestors of modern Scandinavians (including the Saami people of northern Scandinavia) but are more closely related to contemporary populations of the eastern Baltic region. Our findings support hypotheses arising from archaeological analyses that propose a Neolithic or post-Neolithic population replacement in Scandinavia [7]. Furthermore, our data are consistent with the view that the eastern Baltic represents a genetic refugia for some of the European hunter-gatherer populations.

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