The end of the Last Glacial Maximum (LGM) in Europe (~16.5 ka ago) set in motion major changes in human culture and population structure. In Southern Europe, Early Epigravettian material culture was replaced by Late Epigravettian art and technology about 18-17 ka ago at the beginning of southern Alpine deglaciation, although available genetic evidence from individuals who lived ~14 ka ago opened up questions on the impact of migrations on this cultural transition only after that date. Here we generate new genomic data from a human mandible uncovered at the Late Epigravettian site of Riparo Tagliente (Veneto, Italy), that we directly dated to 16,980-16,510 cal BP (2σ). This individual, affected by a low-prevalence dental pathology named focal osseous dysplasia, attests that the very emergence of Late Epigravettian material culture in Italy was already associated with migration and genetic replacement of the Gravettian-related ancestry. In doing so, we push back by at least 3,000 years the date of the diffusion in Southern Europe of a genetic component linked to Balkan/Anatolian refugia, previously believed to have spread during the later Bolling/Allerod warming event (~14 ka ago). Our results suggest that demic diffusion from a genetically diverse population may have substantially contributed to cultural changes in LGM and post-LGM Southern Europe, independently from abrupt shifts to warmer and more favourable conditions.Bortolini et al., Early Alpine human occupation backdates westward human migration in Late Glacial Europe, bioRxiv, posted August 10, 2020, doi: https://doi.org/10.1101/2020.08.10.241430 See also... Villabruna cluster =/= Near Eastern migrants
search this blog
Showing posts with label Southern Europe. Show all posts
Showing posts with label Southern Europe. Show all posts
Tuesday, August 11, 2020
Villabruna people existed in Europe at least 17,000 years ago (Bortolini et al. 2020 preprint)
Over at bioRxiv at this LINK. So, like I said here a few years back, there was no migration into Europe from the Near East ~14,00 years ago. I don't think there was even such a migration ~17,000 years ago. My view is that the so called Villabruna cluster formed somewhere in Europe at least 20,000 years ago. Below is the Bortolini et al. abstract, emphasis is mine:
Sunday, November 10, 2019
Etruscans, Latins, Romans and others
I've just added coordinates for more than 100 ancient genomes from the recently published Antonio et al. ancient Rome paper to the Global25 datasheets. Look for the population and individual codes listed here. Same links as always:
Global25 datasheet ancient scaled Global25 pop averages ancient scaled Global25 datasheet ancient Global25 pop averages ancientThus far I've only managed to check a handful of the coordinates, so please let me know if you spot any issues. Below is a Principal Component Analysis (PCA) featuring the Etruscan and Italic speakers. I ran the PCA with an online tool specifically designed for Global25 coordinates freely available here. Can we say anything useful about the origins of the Etruscan and early Italic populations thanks to these new genomes? Also, to reiterate my question from the last blog post, what are the genetic differences exactly between the Etruscans, early Latins, Romans and present-day Italians? Feel free to let me know in the comments below. Update 13/11/2019: Here's another, similar PCA. This one, however, is based on genotype data, and it also highlights many more of the samples from the Antonio et al. paper. Considering these results, I'm tempted to say that the present-day Italian gene pool largely formed in the Iron Age, and that it was only augmented by population movements during later periods. The relevant datasheet is available here. Update 13/11/2019: It seems to me that the two Latini-associated outliers show significant ancestry from the Levant, which possibly means that they're in part of Phoenician origin. These qpAdm models speak for themselves:
ITA_Ardea_Latini_IA_o ITA_Proto-Villanovan 0.547±0.081 Levant_ISR_Ashkelon_IA2 0.453±0.081 chisq 7.573 tail prob 0.87027 Full output ITA_Prenestini_tribe_IA_o ITA_Proto-Villanovan 0.679±0.068 Levant_ISR_Ashkelon_IA2 0.321±0.068 chisq 7.222 tail prob 0.89033 Full outputThe Proto-Villanovan singleton is also a key part of the models. Dating to the Bronze Age/Iron Age transition, she appears to be of western Balkan origin. Moreover, her steppe ancestry is probably derived directly from the Yamnaya horizon.
ITA_Proto-Villanovan HRV_Vucedol 0.677±0.031 Yamnaya_RUS_Samara 0.323±0.031 chisq 10.397 tail prob 0.661174 Full outputThe cluster made up of four early Italic speakers can be modeled with minor Proto-Villanovan-related ancestry, but, perhaps crucially, it doesn't need to be. Indeed, judging by the qpAdm output below, it's possible that almost all of its steppe ancestry came from the Bell Beaker complex, and, thus, the Corded Ware culture complex before that.
ITA_Italic_IA Bell_Beaker_Mittelelbe-Saale 0.480±0.055 ITA_Grotta_Continenza_CA 0.411±0.042 ITA_Proto-Villanovan 0.109±0.084 chisq 10.294 tail prob 0.590205 Full outputTwo out of the three available Etruscans look very similar to the Italic speakers in the above PCA plots, and yet they show a lot more Proto-Villanovan-related ancestry in my qpAdm run. The statistical fit is also relatively poor, perhaps suggesting that something important is missing.
ITA_Etruscan Bell_Beaker_Mittelelbe-Saale 0.186±0.081 ITA_Grotta_Continenza_CA 0.283±0.064 ITA_Proto-Villanovan 0.531±0.126 chisq 17.175 tail prob 0.143143 Full outputInterestingly, the Etruscan outlier with significant North African admixture (proxied in my run by MAR_LN) doesn't need to be modeled with any Bell Beaker ancestry.
ITA_Etruscan_o ITA_Proto-Villanovan 0.675±0.057 MAR_LN 0.325±0.057 chisq 14.864 tail prob 0.315912 Full outputUpdate 17/11/2019: The spatial maps below show how three groups of ancient Romans (from the Imperial, Late Antiquity and Medieval periods) compare to present-day West Eurasian populations in terms of their Global25 coordinates. The hotter the color, the higher the similarity. More here. See also... Getting the most out of the Global25
Labels:
admixture,
ancient DNA,
Ancient Greece,
Ancient Rome,
archaeogenetics,
Etruscans,
Global25,
Italic,
Italy,
Latin,
Levant,
Mediterranean,
Middle East,
North Africa,
Pontic-Caspian steppe,
Roman Empire,
Southern Europe
Thursday, November 7, 2019
What's the difference between ancient Romans and present-day Italians?
The first paper on the genomics of ancient Romans was finally published today at Science [LINK]. It's behind a paywall, but the supplementary info is freely available here. Below is a quick summary of the results courtesy of the accompanying Ancient Rome Data Explorer.
I'm told that the genotype data from the paper will be online within a day or so at the Pritchard Lab website here. I'll have a lot more to say about ancient Romans and present-day Italians after I get my hands on it.
See also...
Etruscans, Latins, Romans and others
Labels:
admixture,
ancient DNA,
Ancient Greece,
Ancient Rome,
archaeogenetics,
Etruscans,
Italian,
Italic,
Italy,
Latin,
Levant,
Mediterranean,
Middle East,
North Africa,
Pontic-Caspian steppe,
Roman Empire,
Southern Europe
Monday, June 3, 2013
Recent gene flow from Africa and the Near East into Europe
A new paper at PNAS by Botigué et al. takes a close look at African and Near Eastern admixture in Europe:
Human genetic diversity in southern Europe is higher than in other regions of the continent. This difference has been attributed to postglacial expansions, the demic diffusion of agriculture from the Near East, and gene flow from Africa. Using SNP data from 2,099 individuals in 43 populations, we show that estimates of recent shared ancestry between Europe and Africa are substantially increased when gene flow from North Africans, rather than Sub-Saharan Africans, is considered. The gradient of North African ancestry accounts for previous observations of low levels of sharing with Sub-Saharan Africa and is independent of recent gene flow from the Near East. The source of genetic diversity in southern Europe has important biomedical implications; we find that most disease risk alleles from genome-wide association studies follow expected patterns of divergence between Europe and North Africa, with the principal exception of multiple sclerosis.
The term "recent" is used throughout the paper to describe the IBD results, but as far as I can see there's no mention of any dates. Based on the data in the very thorough Ralph and Coop European IBD study (see here), I'd say that segments of over 1.5cM represent gene flow from well within the past 5,000 years. If this assumption is correct, then the results certainly make a lot of sense. That's because there were well documented historical events that could account for the main outcomes in the figure below: a) low level IBD sharing between Sub-Saharan Africa and much of Southern Europe; b) inflated IBD sharing between North Africa and Southwestern Europe; and c) inflated IBD sharing between Southeastern Europe and the Near East.
I probably don't need to discus in detail what these events might have been. Suffice it to say that the Mediterranean Basin has seen several major empires which facilitated regular population movements between Southern Europe, North Africa and the Near East. This process included the slave trade, which was one of the main economic activities in the region for a couple thousand years.
It's important to note, however, that fastIBD doesn't specify the direction of gene flow. In other words, shared IBD segments can be the result of our ancestors either receiving or giving admixture, or gene flow from a third party. But as Botigué et al. point out, the North African samples which show the highest IBD sharing with Iberians are also those with the lowest European ancestry proportions in the ADMIXTURE analysis (see below). Therefore, it's unlikely that this shared IBD is of European origin in any significant degree.
Key: Canis - Canary Islands; And - Andalusia; Gal - Galicia; Bas - Basques; Spa - Spain; Por - Portugal; Fra - France; Ita - Italy; Tsi - Tuscany; Gre - Greece ; ItaJ - Italian Jews; AshJ - Ashkenazi Jews; Qat - Qatar; NMor - North Morocco; SMor - South Morocco; OccS - Saharawi; Alg - Algeria; Tun - Tunisia; Lib - Libya; Egy - Egypt; Yri - Yoruba from Nigeria; Mkk - Maasai from Kenya.
There's also a PCA in the supplementary PDF which further underlines that most of the IBD sharing between Europe and North Africa, as well as Qatar, is not of European origin, because it creates significant substructures within the European sample.
Unfortunately the Qataris are the only Near Eastern sample used in the study. Then again, if I was to pick a single ethnic group to represent the Near East in an IBD study like this, then Qataris would probably be near the top of the list. That's because they've been affected by population movements from other parts of the Arabian Peninsula and also Persia, but at the same time never experienced significant gene flow from Europe. More information about the genome-wide genetic ancestry of Qataris is available in this recent open-access paper by Omberg et al.
Botigué et al. also make some interesting comments about Jewish genetic ancestry in Europe. The quote below comes from the supplementary PDF.
Another possible hypothesis to explain the increased diversity in southern Europe is that an influx of Jewish ancestry had a heterogeneous effect on genetic diversity in Europe. However, in most European populations here, virtually no Jewish ancestry was detected. On average, 1% of Jewish ancestry is found in Tuscan HapMap population and Italian Swiss, as well as Greeks and Cypriots. This may reflect the higher sharing with Near Eastern populations in the Italian peninsula and southeastern Europe (Fig. 2C) or low levels of gene flow with the early Italian Jewish communities (6). Estimates from the IBD analysis are in agreement with ADMIXTURE estimates that the amount of sharing between these populations is extremely low (SI Appendix, Table S3). Specifically, results of IBD sharing between southwestern Europe and North Africa are two orders of magnitude greater than those found between the same region and Jews, the average WEA for southern Europe and North Africa is 203, while for southwestern Europe and European Jews is 1.3.
Reference...
LR Botigué*, BM Henn*, S Gravel, BK Maples, CR Gignoux, E Corona, G Atzmon, E Burns, H Ostrer, C Flores, J Bertranpetit, D Comas, CD Bustamante, Gene flow from North Africa contributes to differential human genetic diversity in Southern Europe, PNAS, published online before print June 3, 2013, doi: 10.1073/pnas.1306223110
Labels:
admixture,
ancestry,
Arabian,
Ashkenazi,
Berber,
Europe,
Iberian,
Italian,
Jewish,
Jews,
Mediterranean,
Middle East,
Moroccan,
Near East,
North Africa,
Portuguese,
Sicilian,
Sicily,
Southern Europe,
Spanish
Subscribe to:
Posts (Atom)