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Showing posts with label Levant. Show all posts
Showing posts with label Levant. Show all posts

Thursday, May 28, 2020

An early Mitanni?


I've updated my Global25 datasheets with most of the ancients from the new Skourtanioti et al. paper. Here's a Principal Component Analysis (PCA) based on the data. It was produced with the Vahaduo PCA tools freely available here and the text file here.


Note that one of the Bronze Age females from Alalakh, labeled ALA019, appears to have ancestry from Turan and the Eurasian steppe. She may well have been a Mitanni of Indo-Aryan origin.

Interestingly, a Copper Age male from Arslantepe, ART038, belongs to Y-haplogroup R1b1a2 aka R1b-V1636. This is an unusual find, because R1b hasn't yet been reported in any Copper Age or earlier samples from outside of Europe and the Eurasian steppe.

As far as I can tell, this individual doesn't harbor any genome-wide ancestry from north of the Caucasus. However, R1b-V1636 is a rare lineage that is first attested in Eneolithic samples from the North Caucasus Piedmont steppe, so ART038's Y-chromosome might be the first evidence of the presence of steppe ancestry in Copper Age Anatolia.

I've also added most of the ancients from the new Agranat-Tamir et al. paper to the Gobal25 datasheets. The PCA below is based on the text file available here.


The Megiddo samples include a trio of interesting outliers dated to 1600-1500 BCE with significant ancestry from the steppe. One of these individuals is a male, I2189, who belongs to Y-haplogroup R and probably R1a. So he might also be of Indo-Aryan origin.

Another Megiddo male, S10768, belongs to R1b-M269 and probably shows a few per cent of steppe ancestry. I've already discussed how R1b and steppe ancestry may have ended up in the Bronze Age Near East in a couple of my previous posts:

R1b-M269 in the Bronze Age Levant

How did steppe ancestry spread into the Biblical-era Levant?

R-V1636: Eneolithic steppe > Kura-Araxes?

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 ancient

Thus 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 output

The 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 output

The 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 output

Two 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 output

Interestingly, 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 output

Update 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

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

Monday, April 22, 2019

R1b-M269 in the Bronze Age Levant


The new Harvard genotype datasets that I blogged about recently include a couple of potentially very useful samples from the Levant dated to 1400-1100 BCE. Search for IDs I2062 and I1934 in the anno files here. They're both from an archeological paper about a Late Bronze Age (LBA) burial site in what is now Israel that was published back in 2017 (see here).

Surprisingly, individual I2062 is listed in the anno files as belonging to Y-haplogroup R1b1a1a2, which is also known as R1b-M269. The reason that this is a surprise to me is because R1b-M269 is closely associated with the Bronze Age expansions of pastoralists from the Pontic-Caspian steppe in Eastern Europe, and these expansions didn't impact the Levant in any direct or significant way.

The Y-haplogroup assignment may or may not be correct. Sometimes the Y-haplogroups in these sorts of datasheets are indeed wrong. Unfortunately, as far as I know, the BAM file for I2062 isn't available anywhere online, so I can't check whether he does really belong to R1b-M269. But, intriguingly, his autosomes do show a subtle signal of Yamnaya-related ancestry from the Pontic-Caspian steppe that is missing in earlier ancients from the Levant.

To characterize his genome-wide ancestry, I first ran a series of unsupervised and supervised analyses with the Global25/nMonte3 method (using this datasheet). For the sake of simplicity, I narrowed things down to the mixture models below based on three reference populations each. Levant_ISR_C is made up of Chalcolithic samples from Israel. The identities of the other reference sets should be obvious to most readers. If confused, feel free to ask for more details in the comments below.

Levant_ISR_MLBA:I2062
Levant_ISR_C,66.8
IRN_Seh_Gabi_C,27
Yamnaya_RUS_Samara,6.2

[1] distance%=1.8905

Levant_ISR_MLBA:I2062
Levant_ISR_C,66.2
Kura-Araxes_ARM_Kaps,30.2
Yamnaya_RUS_Samara,3.6

[1] distance%=2.0856

Levant_ISR_MLBA:I2062
Levant_ISR_C,67.8
Kura-Araxes_RUS_Velikent,31.8
Yamnaya_RUS_Samara,0.4

[1] distance%=2.1738

To further confirm the reliability of my models, I tested them with the formal statistics-based qpAdm software. As far as I can tell, the output from qpAdm looks very solid across the board.

Levant_ISR_MLBA_I2062
IRN_Seh_Gabi_C 0.193±0.052
Levant_ISR_C 0.710±0.038
Yamnaya_RUS_Samara 0.098±0.026

chisq 9.304
tail prob 0.67676
Full output

Levant_ISR_MLBA_I2062
Kura-Araxes_ARM_Kaps 0.249±0.076
Levant_ISR_C 0.681±0.051
Yamnaya_RUS_Samara 0.071±0.035

chisq 11.101
tail prob 0.52032
Full output

Levant_ISR_MLBA_I2062
Levant_ISR_C 0.661±0.042
Kura-Araxes_RUS_Velikent 0.339±0.042

chisq 7.979
tail prob 0.844942
Full output

Admittedly, even though I2062 can be modeled with Yamnaya-related admixture, he doesn't need to be. Indeed, his ratio of this type of ancestry varies significantly between the models, from around 10% to nothing. This appears to be dependent on the geography of the non-Levant and non-Yamnaya reference populations; the closer they are to the Pontic-Caspian steppe, the smaller the ratio of Yamnaya-related ancestry in I2062. I'd describe this as an artifact of the isolation-by-distance phenomenon, and it totally makese sense, but it prevents me from confirming beyond any doubt that I2062 does harbor genome-wide steppe ancestry. Unfortunately, individual I1934 doesn't offer enough data to be analyzed with the same methods.

Samples associated with the Kura-Araxes or Early Transcaucasian culture are particularly strong references for the eastern ancestry in I2062. This probably isn't a coincidence, and it might also explain his Y-haplogroup, because, at its maximum extent, the territory occupied by the Kura-Araxes culture stretched all the way from the Pontic-Caspian steppe to the southern Levant. The map below is from Wilkinson 2014.

See also...

Downloadable genotypes of present-day and ancient DNA data

Early chariot riders of Transcaucasia came from...

R-V1636: Eneolithic steppe > Kura-Araxes?