I2-M438 and Scandinavian Hunter-Gatherers
Haplogroup I2-M438 formed ca. 25500 BC, and the modern European population has a TMRCA ca. 19900 BC. Individuals from Mesolithic Scandinavia, which define the so-called Scandinavian Hunter-Gatherer (SHG) ancestry, show exclusively I2-M438 lineages. In samples of Mesolithic SHG, together with those of WHG and EHG ancestry (but for those of the Balkans), mtDNA haplogroups U5 and U2 are prevalent[Mathieson et al. 2017].
The ice sheet retracted from northern Europe allowed for the colonisation of the Scandinavian Peninsula from about 9700 BC, according to the archaeological record, both in southern and northern Scandinavia, while ice still dominated the interior. The peninsula seems to have been colonised first from the south by peoples from central Europe, related to late-glacial lithic technology (direct blade percussion technique), which brought WHG ancestry with them.
Genomic studies show an invasion from the north-east by peoples from east Europe, who brought EHG ancestry. Their technology is probably represented in the ‘pressure blade’ technique found in northern parts of Scandinavia.
This left a paradoxical pattern of increased EHG ancestry in north and west Scandinavia, and WHG ancestry in east and central Scandinavia, which correlates with Baltic samples. It has also been shown that selection drove the unique combination of light skin and hair and varied blue to light-brown eye colour, as part of the adaptation to a different environment, in contrast with WHG who had the specific combination of blue eyes and dark skin[Günther et al. 2017].
Scandinavian Hunter-Gatherer (SHG) ancestry, therefore, represents a mixed group tracing parts of their ancestry to both WHG and EHG.
Many ancient DNA samples of I2-M438 haplogroups are found since the Palaeolithic, and two main branches seem to have divided early: I2a1b2-L621 lineages are found mainly in the Balkans, and I2a2a-M223 – distributed through central Europe – seems to have followed the expansion of Italo-Celtic and Germanic, and were therefore possibly integrated with R1b1a1a2a1a-L151 lineages since the Bell Beaker complex.
Image modified from Günther et al. (2017). «Mesolithic samples and their genetic affinities – (A) Map of the Mesolithic European samples used in Günther et al. (2017). The pie charts show the model-based estimates of genetic ancestry for each SHG individual. The map also displays the ice sheet covering Scandinavia 10,000 BP (most credible (solid line) and maximum extend (dashed line) ). Newly sequenced sites are shown in bold and italics. Additional European EHG and WHG individuals used in this study derive from sites outside this map. (B) Magnified section of genetic similarity among ancient and modern-day individuals using PCA featuring only the Mesolithic European samples». Original under a CC-BY-NC 4.0 International license.
- [Fu et al. 2016] ^ Fu, Q., C. Posth, M. Hajdinjak, M. Petr, S. Mallick, D. Fernandes, A. Furtwangler, W. Haak, M. Meyer, A. Mittnik, B. Nickel, A. Peltzer, N. Rohland, V. Slon, S. Talamo, I. Lazaridis, M. Lipson, I. Mathieson, S. Schiffels, P. Skoglund, A. P. Derevianko, N. Drozdov, V. Slavinsky, A. Tsybankov, R. G. Cremonesi, F. Mallegni, B. Gely, E. Vacca, M. R. Morales, L. G. Straus, C. Neugebauer-Maresch, M. Teschler-Nicola, S. Constantin, O. T. Moldovan, S. Benazzi, M. Peresani, D. Coppola, M. Lari, S. Ricci, A. Ronchitelli, F. Valentin, C. Thevenet, K. Wehrberger, D. Grigorescu, H. Rougier, I. Crevecoeur, D. Flas, P. Semal, M. A. Mannino, C. Cupillard, H. Bocherens, N. J. Conard, K. Harvati, V. Moiseyev, D. G. Drucker, J. Svoboda, M. P. Richards, D. Caramelli, R. Pinhasi, J. Kelso, N. Patterson, J. Krause, S. Paabo, and D. Reich. 2016. The genetic history of Ice Age Europe. Nature 534 (7606):200-5. DOI: 10.1038/nature17993.
- [Günther et al. 2017] ^ 1 2 Günther, Torsten, Helena Malmström, Emma Svensson, Ayça Omrak, Federico Sánchez-Quinto, Gülşah M. Kılınç, Maja Krzewińska, Gunilla Eriksson, Magdalena Fraser, Hanna Edlund, Arielle R. Munters, Alexandra Coutinho, Luciana G. Simões, Mário Vicente, Anders Sjölander, Berit Jansen Sellevold, Roger Jørgensen, Peter Claes, Mark D. Shriver, Cristina Valdiosera, Mihai G. Netea, Jan Apel, Kerstin Lidén, Birgitte Skar, Jan Storå, Anders Götherström, and Mattias Jakobsson. 2017. Genomics of Mesolithic Scandinavia reveal colonization routes and high-latitude adaptation. bioRxiv. https://doi.org/10.1101/164400
- [Kilinc et al. 2016] ^ Kilinc, G. M., A. Omrak, F. Ozer, T. Gunther, A. M. Buyukkarakaya, E. Bicakci, D. Baird, H. M. Donertas, A. Ghalichi, R. Yaka, D. Koptekin, S. C. Acan, P. Parvizi, M. Krzewinska, E. A. Daskalaki, E. Yuncu, N. D. Dagtas, A. Fairbairn, J. Pearson, G. Mustafaoglu, Y. S. Erdal, Y. G. Cakan, I. Togan, M. Somel, J. Stora, M. Jakobsson, and A. Gotherstrom. 2016. The Demographic Development of the First Farmers in Anatolia. Curr Biol 26 (19):2659-2666.
- [Mathieson et al. 2017] ^ 1 2 Mathieson, Iain, Songül Alpaslan Roodenberg, Cosimo Posth, Anna Szécsényi-Nagy, Nadin Rohland, Swapan Mallick, Iñigo Olade, Nasreen Broomandkhoshbacht, Olivia Cheronet, Daniel Fernandes, Matthew Ferry, Beatriz Gamarra, Gloria González Fortes, Wolfgang Haak, Eadaoin Harney, Ben Krause-Kyora, Isil Kucukkalipci, Megan Michel, Alissa Mittnik, Kathrin Nägele, Mario Novak, Jonas Oppenheimer, Nick Patterson, Saskia Pfrengle, Kendra Sirak, Kristin Stewardson, Stefania Vai, Stefan Alexandrov, Kurt W. Alt, Radian Andreescu, Dragana Antonović, Abigail Ash, Nadezhda Atanassova, Krum Bacvarov, Mende Balázs Gusztáv, Hervé Bocherens, Michael Bolus, Adina Boroneanţ, Yavor Boyadzhiev, Alicja Budnik, Josip Burmaz, Stefan Chohadzhiev, Nicholas J. Conard, Richard Cottiaux, Maja Čuka, Christophe Cupillard, Dorothée G. Drucker, Nedko Elenski, Michael Francken, Borislava Galabova, Georgi Ganetovski, Bernard Gely, Tamás Hajdu, Veneta Handzhyiska, Katerina Harvati, Thomas Higham, Stanislav Iliev, Ivor Janković, Ivor Karavanić, Douglas J. Kennett, Darko Komšo, Alexandra Kozak, Damian Labuda, Martina Lari, Catalin Lazar, Maleen Leppek, Krassimir Leshtakov, Domenico Lo Vetro, Dženi Los, Ivaylo Lozanov, Maria Malina, Fabio Martini, Kath McSweeney, Harald Meller, Marko Menđušić, Pavel Mirea, Vyacheslav Moiseyev, Vanya Petrova, T. Douglas Price, Angela Simalcsik, Luca Sineo, Mario Šlaus, Vladimir Slavchev, Petar Stanev, Andrej Starović, Tamás Szeniczey, Sahra Talamo, Maria Teschler-Nicola, Corinne Thevenet, Ivan Valchev, Frédérique Valentin, Sergey Vasilyev, Fanica Veljanovska, Svetlana Venelinova, Elizaveta Veselovskaya, Bence Viola, Cristian Virag, Joško Zaninović, Steve Zäuner, Philipp W. Stockhammer, Giulio Catalano, Raiko Krauß, David Caramelli, Gunita Zariņa, Bisserka Gaydarska, Malcolm Lillie, Alexey G. Nikitin, Inna Potekhina, Anastasia Papathanasiou, Dušan Borić, Clive Bonsall, Johannes Krause, Ron Pinhasi, and David Reich. 2017. The Genomic History Of Southeastern Europe. bioRxiv. https://doi.org/10.1101/135616