Paleolithic DNA from the Caucasus

[ratchet_fan]

What he says is that " ‘Mbuti’ ancestry represents the total of ‘Deep’ ancestry from lineages that split prior to the366 split of Ust’Ishim, Tianyuan, and West Eurasians and can include both ‘Basal Eurasian’ and367 other (e.g., Sub-Saharan African) ancestry. "

So, there could be "extra" Basal in there, a lineage that split before Basal, as well as any modern SSA or East African in people. Remember the SSA that used to show up in ancient samples? If the algorithm spotted something really old it threw it in SSA perhaps.
He has no sample for these deep lineages that include not only Basal Eurasian but other lineages that split off before Basal. There's also the language about bottlenecked and non-bottlenecked lineages. Which one was which, the Basal or the pre-Basal? What was the bottleneck, what caused it, where?

Looking at this graph I'm struck by the Dzudzuana in the more "eastern" hunter-gatherers, like Ukraine, Norway, Sweden, Russian Mesolithic, Motala and Iron Gates. Movement westward from the Caucasus? Or straight from Anatolia?

Part of that is Basal Eurasian.

You can also see it in the graph of the amount of Basal Eurasian. According to that, the hunter gatherers had what looks like from 1 to 10%, which is just about what the Feldman et al (Krause) paper on Anatolian hunter-gatherer transition to farmer said would be in the ball park for the amount of Basal Eurasian that would need to be in Iron Gates if there had been movement from Anatolia to Europe at that period. Of course, they only found something like 1.6.

I believe even Mata needs CHG admixture.

 

[ratchet_fan]

there is another admixture graph, fig 2.13

CHG is modelled as a 93 % mixture of 70 % Dzudzuana + 30 % Tianyuan-like with 7 % Taforalt

CHG = 0.93 * (0.7 Dzu + 0.3 Tian) + 0.07 Taforalt

So first another 30 % Tianyuan was added and then another 7 % Taforalt

on the same graph :

Iran Neo = 0.81 (0.65 Dzudzuana + 0.35 Tianyuan) + 0.19 Basal Eurasian

Instead of extra Tarofalt, Iran Neo has extra Basal Eurasian

Are these models still considered accurate? That would make CHG and Iran_Neo about 27% East Eurasian.

 

[ratchet_fan]

Is there any update on this genome being released? I heard the lab is working on a paper. Are there any new samples? Where did West Eurasians split from East Eurasians?

 

[Regio X]

Seems unlikely to me. WOuldn't AASI have been first that east?

Yeah, South Asia as the source of BE looks unlikely, especially now. What Razib said here about it seems to make sense.

 

[ratchet_fan]

Yeah, South Asia as the source of BE looks unlikely, especially now. What Razib said here about it seems to make sense.

IMO though South Asia could be a major sink for Basal Eurasian. There's no ancient DNA to support it but it wouldn't surprise me if that is the first component to settle the region. I don't see too many AASI makers in their ydna and mtdna M in South Asia seems to be younger and derivative of SE Asian mtdna M.

 

[kingdavid]

this is intersting abstract

Metagenomes and ancient human lineages from a pre-LGM layer of Satsurblia cave in the Caucasus

Here we present genomic data from sediment from an Upper Paleolithic occupational level of Satsurblia cave, Imereti region,western Georgia, dated to 25, 000 years before present (bp). The site has yielded a rich archaeological record for Upper Palaeolithic occupation which spans from 33,000-14,000 years before present [2]. A previous study of a complete human genome from a human right temporal bone from this site, dated to the Late Upper Palaeolithic (13,132–13,380 cal bp) [3], showed that the post-LGM population which inhabited this region, were ‘Caucasus hunter-gatherers’ (CHG), a main source population for several Eurasian populations. However, the genetic composition of the pre-LGM inhabitants of the region remains unknown as there are no genomic data for this period for Western Eurasia.

We report the recovery and analysis of a human mitochondrial genome with clear genetic affinity to Bacho Kiro mitogenomes from Bulgaria, dated to 45,000 years bp [4]. The analysis of the nuclear genome shows that the recovered human data does not cluster with the previous reported genome from Satsurbila Cave, in contrast it appears to be close to the present-day Levant populations.This results evidence of genetic discontinuity during the LGM in the Southern Caucasus region.

Additionally, in the same layer we have also identified the presence of three other mammal species:C. lupus, B. taurus and Ovis species. The genomic comparison of these lineages revealed relevant data on the evolution of these species as well as the interaction between humans and human-related species.


source:
ESHE abstracts are online:
https://www.eshe.eu/static/eshe/file..._Abstracts.pdf

 

[Malaparte]

I think some of the usual suspects are shell shocked. "I can't find anything wrong with the analyses, but it can't be right."

My overriding impression, and I think what any honest layperson would see, is that all of the barriers we put up between most of the different West Eurasian groups is really just nonsense. Peel back enough layers and you'll see the common core.

Didn't Reich claim somewhere that there was more genetic distance between WHG, AN and Steppe than exists in modern times between Europeans, East Asians, and SSA? Doesn't the 2018 Lazaridis paper on Dzudzuana speak against this claim, as it looks like all the various foraging groups were interrelated well before the dawn of the Neolithic?

 

[Diictodon]

I read somewhere that Dzudzuana requires ANA in them and Pinarbasi requires more WHG beyond the UHG stuff in them and that mtDNA K1a was WHG mediated. Some AHG has Y-C1b and I-M70 in them

 

[Jovialis]

Pre-Print Lazaridis et al. 2018

The authors used ADMIXTUREGRAPH to fit a deep ancestry model for European hunter-gatherers. They found that the first populations related to present-day West Eurasians arrived in Europe at least 36 thousand years ago, and that by ~14kya a third group, the Villabruna cluster, appeared throughout mainland Europe. The Dzudzuana-related population admixed with North African-related ancestry in the Levant and with Siberian hunter-gatherer and eastern non-African-related ancestry in Iran and the Caucasus.
References

Pre-Print Lazaridis et al. 2018
Section 1, paragraphs [1], [2], [6], [11], [12], [13], [15]
Section 2, paragraphs [1], [2]
Section 3, paragraph [1]

• Dzudzuana is the largest single contributor of ancestry of all present-day West Eurasians.
• Ancient DNA has revealed more about the deep history of Europe than of any other continent. Genetic analyses show that the first populations related to present-day West Eurasians arrived in Europe at least 36 thousand years ago.
• No Ice Age DNA has been published from the Near East (including the Caucasus) whose post-glacial and Holocene-era populations <15kya were highly differentiated. To address this deficit, we analyzed teeth from two individuals recovered from Dzudzuana Cave 15 in the Southern Caucasus.
• The Dzudzuana samples represent the earliest ancient modern human DNA outside of Europe, Siberia, and China. They help us answer the question of the relationship of Ice Age populations of the region to their post-glacial successors.
• Outgroup f 3 -statistics 10 show that Dzudzuana clusters with Near Eastern populations primarily from Anatolia and secondarily from the Levant. A genetic relationship between Dzudzuana and Neolithic Anatolians is also shown by principal components analysis.
• To better understand the relationship of Dzudzuana to other ancient West Eurasian populations, we performed symmetry testing using f-statistics 18. ESHG share more alleles with Dzudzuana than with PGNE populations, except Neolithic Anatolians who form a clade with Dzudzuana.
• All known ancient Near Eastern populations prior to this work were inferred to harbor 'Basal Eurasian' ancestry 9, a branch that diverged from all other non-Africans. The detection of this type of ancestry, twice as early as previously documented 5,6 lends weight to the hypothesis that it represents a deep Near Eastern lineage.
• We used qpGraph 18 to build an admixture graph model of the relationship between ESHG and Dzudzuana. The model is useful for its insights into possible evolutionary relationships between populations.
• Our model predicts that West Africans had 12.5±1.1% ancestry from a Taforaltrelated group rather than Taforalt having ancestry from an unknown Sub-Saharan African source. Such a scenario would also explain the presence of Y-chromosome haplogroup E.
• Africans.
• We cannot reject the hypothesis that Dzudzuana and the much later Neolithic Anatolians form a clade with respect to ESHG (P=0.286), consistent with the latter being a population largely descended from Dzudzuana-like pre-Neolithic populations. Dzudzuana itself can be modeled as a 2-way mixture of Villabruna-related ancestry.
• Western PGNE populations can all be modeled as a mixture of Dzudzuana and additional 'Deep' ancestry. Karelia_HG can be modeled as deriving 34±2.8% of its ancestry from a Villabruna-related source.
• In qpAdm modeling, a deeply divergent hunter-gatherer lineage contributed in relatively unmixed form to the much later hunter-gatherers of the Villabruna cluster. In Europe, descendants of this lineage admixed with pre-existing hunter-gatherers related to Sunghir3 from Russia. In the Near East it did so with Basal Eurasians.
• The ancestry of present-day Europeans has been traced to the proximate sources of Mesolithic hunter-gatherers, Early European/Anatolian farmers, and steppe pastoralists. The ancestry of Near Eastern and North African populations has not been investigated.
• Dzudzuana stands in the middle of an ongoing process of admixture of diverse elements from which West Eurasians eventually formed.

 

[Jovialis]

If this is true, the "Genetic Bridge" is not so much a panmixia, but rather closer to the "Genetic Core" from which the peripherals are augmented from.

https://twitter.com/x/status/1861073938391921001

 

[Palermo Trapani]

Jovialis:

What is the status of this paper by Lazaridis et al 2018 (pre-print)?

 

[Jovialis]

Jovialis:

What is the status of this paper by Lazaridis et al 2018 (pre-print)?

Dead thus far.

If someone ever finds Basal Eurasians, maybe it would see the light of day in another iteration perhaps.

 

[bicicleur 2]

Dead thus far.

If someone ever finds Basal Eurasians, maybe it would see the light of day in another iteration perhaps.

any area where we don't have any homo sapiens DNA older than 26000 years

 

[Palermo Trapani]

Dead thus far.

If someone ever finds Basal Eurasians, maybe it would see the light of day in another iteration perhaps.

Ok, that makes sense. Seems to me there is enough there in that paper to publish it but I guess the linking it to the hypothetical Basal Eurasians requies some DNA samples to substantiate that hypothesis.

Thanks, PT