Pots, Not People, in Northwest Anatolia?

Posted on by populationgenomics

As pointed out to me, by Rob, it appears there is a new date for a sample from Barcin Hoyuk, in Turkey. This sample (I0707) is now dated to the Mesolithic (9650-9291 cal BCE). This is a huge find, as it changes the view of the way agriculture got to the region, all together. I feel that this may be the biggest thing included in the Wang et al (2018) paper, but others interested in Indo-European studies may disagree. I have contacted the authors to verify this, just to be sure.

Nearly everyone has interpreted the appearance of agriculture in NW Anatolia to some other place in Anatolia, via migration. This often includes Hacilar and Catalhoyuk. This is based on some similarities in pottery, but does ignore the differences in domestic plants in use, as well as the architecture in NW Anatolia.

With this new sample, it appears we may have our first evidence of agriculture and animal husbandry being adopted by a local, or near-local Mesolithic group. Using data available from Mathieson et al (2018) and Lazaridis et al (2016), I decided to compare how this Mesolithic sample compares to the farmers of Barcin, 3000 years later. The results were quite shocking.

 

Anatolia_N and Meso_Anatolia Form a Clade, With Respect To Other Groups

The following D-stats detail that the average of all farmers and the Mesolithic Barcin sample are nearly identical, only deviating with a Z>2 for Ukraine_N, towards Anatolia_N.

Outgroup Test X Y D Z-Score SNPs
Chimp CHG Anatolia_N Meso_Ana 0.000322 0.792 946889
Chimp Iran_N Anatolia_N Meso_Ana -0.000379 -0.895 751697
Chimp Iron_Gates Anatolia_N Meso_Ana -0.000465 -1.348 945737
Chimp Natufian Anatolia_N Meso_Ana -0.000126 -0.258 454638
Chimp Ukraine_N Anatolia_N Meso_Ana -0.000831 -2.441 877282
Chimp Levant_N Anatolia_N Meso_Ana -0.000047 -0.122 737416
Chimp Hajji_Firuz Anatolia_N Meso_Ana -0.000022 -0.062 879843
Chimp Pponnese_N Anatolia_N Meso_Ana 0.000149 0.435 917602
Chimp Starcevo Anatolia_N Meso_Ana -0.000125 -0.351 880994

 

F3-ratio test for Potential Admixture

In agreement with the D-stats, there is only one stat that sees a Z-score >3 for admixture going from Meso_Anatolia to Anatolia_N. This was with Ukraine_N, suggesting that there is potentially a pop nearby that contains some of this ancestry. Possibly from around Bulgaria.

Source 1 Source 2 Target f_3 std. Error Z SNPs
Meso_Ana Iron_Gates Anatolia_N -0.00164 0.000896 -1.831 745983
Meso_Ana Ukraine_N Anatolia_N -0.003474 0.000917 -3.787 671035
Meso_Ana Levant_N Anatolia_N -0.000648 0.001014 -0.639 547417
Meso_Ana CHG Anatolia_N 0.001094 0.001347 0.812 691079
Meso_Ana Iran_N Anatolia_N -0.002526 0.001415 -1.785 556216

 

qpAdm Model of Anatolia_N Using Meso_Anatolia

This testing also showed agreement with D-stats and f3-ratio. Anatolia_N was modeled as a two-way mixture of Meso_Anatolia and Ukraine_N. For the outgroups, I have used Chimp, Iron_Gates, Ust_Ishim, EHG, West_Siberia_N, IBM (Iberomaurusians), Ganj_Dareh_N, Brazil_LopaDoSanto_9600BP, Natufian, and CHG.

The test was also successful in modeling Anatolia_N as a mix of about 97 percent Meso_Anatolia, with 3 percent admixture from a source similar to Ukraine_N.

numsnps used: 520478

best coefficients: 0.970 0.030

std. errors: 0.017 0.017

fixed pat     wt    dof      chisq       tail prob

   00                0        8        5.839      0.665269

 

qpGraph Modeling of Anatolia_N

As a final check, I ran qpGraph to see if there would be more confirmation of the above stats.

While more complex, I tried to include several pops as the outgroups, or admixture sources in the creation of Meso_Anatolia, and how this compares to Anatolia_N. I have included Chimp as the outgroup, with CHG, Ust_Ishim, Natufians, Iron_Gates, and Ukraine_N as potential sources of ancestry and additional admixture for Anatolia_N. This first graph, is the base of Meso Anatolia, where a mix of a pop similar to Iron_Gates, Natufians, and CHG does well to create the potential source population at Barcin Hoyuk during the Mesolithic.

anatolians1.png

For the next graph, I included Anatolia_N, connected to the Mesolithic Barcin sample. Essentially seeing if they are a clade, as this was the heavy favorite in Z-score, when not attaching Anatolia_N to any one population.

anatolians2.png

These two populations did indeed, essentially form a clade. There isn’t a great deal of reason to improve this, but with the stat connecting Anatolia_N to Ukraine_N, I figured I would explore that and see if improved the fit.

Anatolians3

This final graph actual showed the same thing as qpAdm, and in agreement with D-stats and f3-ratio, with Anatolia_N needing admixture from a population similar to Ukraine_N, at a rate of 3 percent. Depending on the response from the authors, to verify the dating of the sample, it does appear that farming was a local event, potentially adopted by the previous Mesolithic inhabitants.

While this is only based on a single sample, there is enough here to suggest the possibility that the Neolithic package arrived in Barcin through cultural exchange, rather than demographic movements. More high quality samples from other parts of Anatolia will help to see if this holds up. Comparison between the shotgun Boncuklu and Barcin samples may have had some artifact affecting the stats showing movements from the Levant. Soon, I will look back at Europe, as the picture there looks much more complex, with some significant stats towards other populations other than hunter gatherers. This could include from the Levant and Eastern Anatolia.

 

 

Sources

Mathieson et al. (2018) The genomic history of southeastern Europe. Nature 555, 197–203 (08 March 2018) https://www.nature.com/articles/nature25778

Lazaridis et al (2016) Genomic insights into the origin of farming in the ancient Near East. Nature 536, 419–424 (25 August 2016) https://www.nature.com/articles/nature19310

Wang et al. (2018) The genetic prehistory of the Greater Caucasus. https://www.biorxiv.org/content/10.1101/322347v1.supplementary-material

 

 

 

 

 

Published by populationgenomics

10 thoughts on “Pots, Not People, in Northwest Anatolia?”

  1. This is indeed a great find. I don’t know why it was not mentioned that they found a Mesolithic sample among the Neolithic ones. We’d need to check for clarification from the authors about the dating (and if it was performed on the bone itself or it’s from somewhere else in the burial). But if everything is correct it’s a really interesting find.

    In Global 25 it also looks pretty much identical to the Neolithic samples, within sample variation. Probably comparing it to other high coverage sample like I1583 might show a Levant_N shift in this latter one rather than the Ukraine_N of the average of samples. However, when using I0707 (Mesolithic) as a base for LBK I don’t see any additional Levant_N. Just the expected WHG shift. So it seems to represent well the farmers that moved to Europe.

    Like

  2. 3,000 years difference to the other samples is quite big, and it would be some gem to have burial data from the Epipaleolithic Marmara, the evidence for which is still tenuous (as its based on mostly lithics, which are surface scatters, and could be typologically Neolithic). It’w worth closely redating the individual.

    Like

  3. If dates valid then, sequence that we have for Anatolia, from Feldman and this is:

    – Anatolian Hunter Gatherer, South-Central Anatolian, directly dated to 13,642-13,073 BCE. Looks like later Barcin group, with less affinity to IranN/CHG and Levant.
    – This sample, I0707, 9650-9291 cal BCE, NW Anatolia. Forms a clade with later NW Anatolian Barcin N farmers, who have more IranN/CHG and Levant affinity than AHG.
    – Early Neolithic Aceramic Anatolian farmers, labeled AAF; c. 8300-7800 cal BCE, Boncuklu – South Central Anatolia. Like AHG with more Iran/CHG related admixture, and should be roughly like I0707 but less Levant affinity.
    – BarcinN, Anatolian Ceramic farmers, labeled ACF; 7,000 – 6,000 cal BCE.

    Suggests that NW Anatolia was enriched with Levant+IranN/CHG ancestry after the AHG, but before I0707?

    Like

  4. ”Suggests that NW Anatolia was enriched with Levant+IranN/CHG ancestry after the AHG, but before I0707?’

    Yes, but the spanner in the worksis that the arecamic Boncuklu is less Levant/Iran shifted c.f. I0707. As Chad, said, it could be sequencing aspects; but to me it makes sense to see gradual eastern shift from AHG -> aceramic -> ceramic Neolithic, due to ongoing admixture of initially smaller, less connected groups.

    Like

  5. @Rob, just to clarify, I mentioned NW Anatolia to imply that C Anatolia where the Aceramic samples from may not follow same dynamics. The Feldman paper tended to treat the published Boncuklu sample as part of their overall Aceramic set, which as a whole they found be more Iran/CHG shifted compared to Barcin set including this sample if (only by being less Levant shifted) though it’s correct to say it’s at the least eastern shifted fringe of that set on their PCA,

    It would make sense to me as well to see gradual eastern shift across Anatolia (allowing for meaning eastern shift to include both Levant+Iran/CHG) and not separate dynamics for NW and Central Anatolia, but does seem like a mesolithic sample at Barcin being a clade with later ceramic neolithic at Barcin would imply flouting that trend, if the sample truly dates to that period.

    Like

  6. Chad, what’s your take on the earliest manifestations of agriculture in southeast Anatolia? Do you think it was a strictly local development or do you think it was engendered by an infusion of Natufian/Levant_Neo ancestry?

    Like

Leave a reply to Alberto Cancel reply