Saturday, April 6, 2013

Let's play with Dienekes' globe10 calculator (I)

The results are a bit old now (october 2012), still I find them interesting because of the introduction of ancient Europeans into the sample.


Ötzi


The spreadsheet is to be found here :


I remind you of my 'globe10' results :

- DOD133 :

#PopulationPercent
1 Atlantic_Baltic 76.20
2 Southern 20.77
3 West Asian 1.05


4South Asian0.89


Other results are probably statistical artefacts and should not be taken into account. Let's see some other populations' results.


1. Neolithic hunter-gatherers (Gotland - South Sweden)

See this article for more data on those ancient samples :


- Ajv52 :

#PopulationPercent
1Atlantic_Baltic91.00
2South Asian5.06
3Amerindian1.90
4Neo African1.60


- Ajv70 :

#PopulationPercent
1Atlantic_Baltic92.60
2Amerindian3.70
3Australasian3.10
4Palaeo African0.50


Quite clearly, the modern component labelled as "Atlantic-Baltic" constituted most of the genetic variation of hunter-gatherers in Neolithic Gotland (Sweden).

Other components are quite exotic and might hint to an archaic variation that had not yet disappeared from Europe, either because of subsequent mixing or because it simply got to change. The algorithm might also just fail to successfully interpretate around 8% of those people's variation as it cannot be found in modern humans anymore.


2. Neolithic farmer (Götaland - South Sweden)


- Gok4 :

#PopulationPercent
1Atlantic_Baltic66.30
2Southern33.70
3West Asian0.00
4South Asian0.00


Those results are quite distinct from neighbouring hunter-gatherers from the island of Gotland : that Neolithic "Swedish" farmer shows results more on par with modern European variations. The Southern component has now appeared : it peaks amongst the Mozabite population in Algeria (around 50% of the genetic variation) and Palestinian people.

Undoubtedly enough, this component was brought by farmer migrants coming from the Middle-East who mixed with aboriginal hunter-gatherers. Those migrants probably had already mixed with aboriginal Europeans during their journey.

Let's simplify things : let's say our farmer is what resulted from the meeting of 1 migrant farmer male and 1 female hunter-gatherer akin to the ones in Gotland. The father was thus around 67,4% Southern (as opposed to the mother's 0,00%) : such result is not to be found amongst modern populations. No population is that high on Southern.

Mathematical models could be developed taking more generations into account but that would be highly hypothetical : actually, we don't know much of Neolithic demographics.

Another issue is that modern populations heavily loaded on "Southern" like Bedouin people also show strong "West Asian" affinities which are non-existent in Neolithic farmers. "West Asian" peaks amongst Balochi people. Did aboriginal Near-Easterners and Caucasian people subsequently mix with people from the Iranian plateau ?

The question remains : where is the source of that "Southern" component ? Quite probably somewhere in the Near-East but bearers of this variation are not to be found unaltered. Still, it is pretty obvious that the "Southern" component is to be linked with farming.


3. Swedish people


- Swedish_D : (14 people)

#PopulationPercent
1Atlantic_Baltic85.30
2Southern5.60
3West Asian5.10
4South Asian1.60


At first sight, it is obvious modern Swedish people are a mix of Neolithic Swedish farmers (provided the likes of Gok4 were stabilized) and the last Neolithic Swedish hunter-gatherers : the proportions could be guessed through statistical models (I'm too rusty to develop them : I haven't studied maths for 10 years ...).

The "West Asian" component was probably brought up by a subsequent migration. Modern-day Caucasian people are around 50% for that component : if we suppose they reached Sweden unaltered, which is probably wrong, that means they were outnumbered by a 1:10 ratio, more than one Caucasian great-grandparent for 7 autochtonous great-grandparents.

It may be hasty but I believe that the "West Asian" component is to be linked with the introduction of Indo-European languages in Europe.

NB : The "South Asian" in modern Europeans is ambiguous (both for Swedes and myself), I won't tackle that issue now.



4. Ötzi (Copper Age Alps)


- Oetzi :

#PopulationPercent
1Atlantic_Baltic49.80
2Southern42.20
3West Asian5.70

4South Asian0.90

Ötzi's remains were found in the Italian Alps, in modern-day German-speaking Tyrol. Pollen analyses have proved Ötzi was autochtonous to the area.

The Copper Age is transitional between Neolithic times and the Bronze Age when Indo-Europeans reached Europe. It looks like Ötzi had already suffered "West Asian" influence, circa 5.70%.

The Atlantic/Southern ratio is pretty balanced which can only mean people like Ötzi vastly descended from Neolithic farmers, as much as they descended from aboriginal Upper-Paleolithic people.



5. North Italian people 


- North_Italian : (11 people)

#PopulationPercent
1Atlantic_Baltic59.40
2Southern25.60
3West Asian14.90
4South Asian0.00

Considering modern-day South Tyrolians partly descend from German-speaking colonists who settled in the Alps from the 8th century onwards, I believe North Italians are more interesting to compare even though I lament the lack of more localized Italian samples.

The "West Asian" in modern-day North Italians is 3 times higher than it was in Ötzi which means North Italy suffered intense migrations in the Bronze Age. These migrations probably brought Indo-European languages.

The Atlantic/Southern ratio is now largely unbalanced : the only explaination is that newcomers in the Bronze Age were both high on the "Atlantic" component and the "West Asian" one, lower on "Southern" ratio wise. Celtic migrations from central Europe ? Unless Ötzi was not representative of the North Italians in those times.


6. Sardinian people 


- Sardinian : (25 people)

#PopulationPercent
1Atlantic_Baltic58.60
2Southern39.00
3West Asian2.40
4South Asian0.00


Amongst the modern populations of Western Europe, not taking South Italians into consideration, Sardinians are the ones showing the lowest Atlantic/Southern ratio, not that far from Ötzi's one. I'd like to add it somehow shows in their more extreme phenotypes even though this is just speculation.

Sardinians rather escaped Bronze Age migrations which brought the "West Asian" component into Western Europe : 2.40% is low. The fact that placenames in mountainous Sardinia appear to be superficially Basco-Iberian-looking is a proof that the "West Asian" component is to be linked with Indo-European languages.

Nevertheless the Basque language, ancient Iberian and ancient Sardinia are not necessarily Upper Paleolithic languages : they could very well be the language of Neolithic farmers or some sort of Neolithic pidgin.


To be followed ...

1 comment:

  1. Other components are quite exotic and might hint to an archaic variation that had not yet disappeared from Europe, either because of subsequent mixing or because it simply got to change. The algorithm might also just fail to successfully interpretate around 8% of those people's variation as it cannot be found in modern humans anymore.

    Assuming ancient HGs mixed with incomers in the Neolithic of Europe this could have involved a bottleneck, which reduced the diversity of what was passed on by the ancient HGs.

    If, as Dienekes suggests, this process was one of longstanding HG and farmer coexistence in Europe, then a number of different bottlenecks may have shaped what comes through as Atlantic Baltic.

    "West Asian" peaks amongst Balochi people. Did aboriginal Near-Easterners and Caucasian people subsequently mix with people from the Iranian plateau ?

    West Asian reaches its peak among Georgians, but they do hit around 25% Southern as well (similar levels of Southern are found in the mainstream of Indo-European speaking Southwest Europeans and Italians - Georgians are about as West Asian as Italians are Atlantic Baltic). It is an interesting possibility some of the the Southern component was brought with a West Asian population to Europe and supplemented Southern already present in the form of Neolithic farmers.

    If we used the Georgians as a reference population for "West Asian" bearers, then at their admixture proportions, an increase of the West Asian component from 0 to 24.6% (as in Greeks) also would have increased Southern by 10%.

    ReplyDelete

I've chosen to let people comment freely on my posts. Nevertheless, you'll lose your time taunting me and calling me a fascist (which I'm really not) : I pray you to read my introduction which will reassure that my intentions genuinely aim at achieving amateurish knowledge. I understand that you may not share my passion for the history of the peopling of the World, just don't let me know as clear conscience gained by bashing a humble documentary work is useless.