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Med
Saturday, May 15th, 2004, 10:03 AM
Two important studies provide some sense of the imprint left on the European gene pool by the spread of agriculture from the Levant beginning ~10,000 YBP:


Neolithic Y-chromosomes



Albanians.............74%
Greeks................71%
Macedonians...........69%
Georgians.............64%
Calabrians............61%
Hungarians............60%
Croatians.............56%
Poles.................52%
North Italians........46%
Ukrainians............44%
Dutchmen..............41%
Germans...............40%
Catalans..............39%
Frenchmen.............38%
Czechs/Slovaks........38%
Andalusians...........31%
Sardinians............15%

(Chikhi et al. 2002 (http://www.pnas.org/cgi/content/full/99/17/11008))


Neolithic mtDNA



01. North-West........22%
02. South-East........20%
03. North-East........18%
04. North-Central.....17%
05. Alps..............15%
06. Western Med.......12%
07. Scandinavia.......12%
08. Eastern Med.......11%
09. Central Med........9%
10. Basque Country.....7%

[01] Irish, English, Welsh, Cornish and French
[02] Bulgarians and Romanians
[03] Finns, Karelians, Estonians, Chuvash, Volga-Finns and Russians
[04] Germans, Czechs, Danes and Poles
[05] Austrians, Swiss and Bavarians
[06] Galicians, Spaniards and Portuguese
[07] Norwegians, Icelanders and Swedes
[08] Greeks and Albanians
[09] Sardinians, Sicilians, Tuscans and Romans
[10] Spanish Basques

(Richards et al. 2000 (http://www.journals.uchicago.edu/AJHG/journal/issues/v67n5/001799/001799.text.html))

morfrain_encilgar
Saturday, May 15th, 2004, 03:01 PM
Two important studies provide some sense of the imprint left on the European gene pool by the spread of agriculture from the Levant beginning ~10,000 YBP:

But in overall genetic distance, the Neolithic component was assimilated outside South-Eastern Europe. Most of Europe forms a genetic group, but South-Eastern Europe is part of the Black Sea area instead. (Don't forget that certain racial elements are found on both continents).

morfrain_encilgar
Saturday, May 15th, 2004, 03:20 PM
Thanks for sharing this interesting piece of information.

It is interesting, but, it isn't the complete story.

These things point to migrations, and theyre useful. But because races are produced by admixture, you need to use the overall genetic evidence, to identify racial groups.

All that Medhammer has shown, is that Neolithic farmers migrated through Europe and left descendants.

Frans_Jozef
Saturday, May 15th, 2004, 04:43 PM
It is interesting, but, it isn't the complete story.

These things point to migrations, and theyre useful. But because races are produced by admixture, you need to use the overall genetic evidence, to identify racial groups.

All that Medhammer has shown, is that Neolithic farmers migrated through Europe and left descendants.


Many months before, I posted on the LBK/Omalian in Belgium as fartherst NW colonisation area of these neolithic farmers. In many other entries I emphasized maximum regional continuity and limited, exclusive gene flow or partial replacement or hybridization(a concept I am very niffy, if not allergic about).

In fact, we see the neolithic gracile types(Mediterrenean?) disappear by the advent of the Bronze Age.
Already fully in the Neolithic more archaic type(Michelsberger Culture) gracility is rivalled.
The Copper Age happens to be incredible harsh to gracile forms, introduces new morphological sturdier type and a stupendous increase of brachycephy, a greater cultural mosaic.

The demographic overthrow of gracility, the main character of the Neolithics, in West Europe goes in favour for the aforementioned robust types(Bell Beakers, SOM Alpinids, the re-emerged cromagnoid in Westphalen and Hessen, and the Aquitain type in South France), an evolution buoyed fully in the Bronze Age whereby Britain, Northern France and the German countries(including Belgium and the Netherlands) are predominantly Nordic, Alpine and *Dinaroid*.

The Belgian LBK didn't last for a long period of time, soon to be replaced by the Alpinids and Séquanians, but also a contigent of Nordic types.
IMO, these races are firmly rooted in NW Europe since the mesolithic and even beyond(Magdalénien, Hamburger, Tsjonger, Federmessen complex).

http://www.forums.skadi.net/printthread.php?t=3677

So, I have hard to understand how this possibly can be congruent with the results of neolithic(?)mtDNA, as listed in this thread.
I cant agree with these results, a likelier explanation would have been that it involves the Maritime Armenoids(Lundman's Litorids), e.g. in the case of the Cornish people.
Also more septentrional movements by the Aunjetitzer Nordics comes in mind.

Vetinari
Monday, May 17th, 2004, 07:59 PM
Two important studies provide some sense of the imprint left on the European gene pool by the spread of agriculture from the Levant beginning ~10,000 YBP:


Neolithic Y-chromosomes



Albanians.............74%
Greeks................71%
Macedonians...........69%
Georgians.............64%
Calabrians............61%
Hungarians............60%
Croatians.............56%
Poles.................52%
North Italians........46%
Ukrainians............44%
Dutchmen..............41%
Germans...............40%
Catalans..............39%
Frenchmen.............38%
Czechs/Slovaks........38%
Andalusians...........31%
Sardinians............15%

(Chikhi et al. 2002 (http://www.pnas.org/cgi/content/full/99/17/11008))


Neolithic mtDNA



01. North-West........22%
02. South-East........20%
03. North-East........18%
04. North-Central.....17%
05. Alps..............15%
06. Western Med.......12%
07. Scandinavia.......12%
08. Eastern Med.......11%
09. Central Med........9%
10. Basque Country.....7%

[01] Irish, English, Welsh, Cornish and French
[02] Bulgarians and Romanians
[03] Finns, Karelians, Estonians, Chuvash, Volga-Finns and Russians
[04] Germans, Czechs, Danes and Poles
[05] Austrians, Swiss and Bavarians
[06] Galicians, Spaniards and Portuguese
[07] Norwegians, Icelanders and Swedes
[08] Greeks and Albanians
[09] Sardinians, Sicilians, Tuscans and Romans
[10] Spanish Basques

(Richards et al. 2000 (http://www.journals.uchicago.edu/AJHG/journal/issues/v67n5/001799/001799.text.html))

I think that Chikhi's data might be wrong. Check out this research:

http://evolutsioon.ut.ee/publications/Barac2003.pdf

Important Quote:

"Our data (12.5%) do not support the estimation of more than 82% of Neolithic contribution in Croatian population suggested by Chikhi et al. Chikhi et al assume homogeneity of Palaeolithic gene pool in Europe by taking only the Basques as representatives of Palaeolithic Europeans thus defining all other lineages by default as Neolithic. This assumption is likely not to hold, at least for haplogroup I, because it is restricted to Europe and almost absent in the Middle-East."

It seems that Chikhi only classifies Haplogroup R1B as being Paleolithic while attributing Haplogroup I to the Neolithic invaders.

The Oracle
Friday, May 28th, 2004, 10:14 AM
I doubt the estimates are wrong. They're not even based on haplogroup frequencies, so Barac's criticism is moot. They were derived using a method that Chikhi et al. argue convincingly is vastly more accurate:


Similarly, Semino et al. (16) have used their results from the non-recombining Y-chromosome region (NRY) to argue that the genetic contribution of Neolithic people may have been as low as 22%. This figure represents the proportion in Europe of the four haplotypes (Eu4, -9, -10, and -11), which were singled out because they show a distinct gradient from the epicenter of the agricultural revolution in the Levant. Although this gradient may well have been established during the Neolithic transition, it is not clear that the proportion of these haplotypes should provide an estimate of admixture proportions. Indeed, admixture is a demographic process, and, as such, it affects the entire genome.

...

One basic reason for the discrepancy between our and Semino et al.'s interpretation is that they used only a subset of information from selected haplotypes. Such an approach could make inefficient use of the data, or introduce bias. Conversely, the likelihood calculations on which our method is based can take advantage of all of the information present in the allelic distributions, without preselection of any allele. ... A particular innovation of our approach is that it estimates the trend in the Neolithic contribution directly, rather than evaluating it indirectly from the clines in allele frequencies.

And even greater accuracy is achieved by factoring in genetic drift:


The method takes into account, and quantifies, the effect of genetic drift since the time of admixture in each population. This innovation in the method is important because the populations are expected to have expanded after acquiring agriculture and, consequently, to have experienced a reduction in genetic drift. Because the archaeological data suggest that the timing of this transition varied from place to place in Europe, the method should be able to pick up a signature of this sequence in the genetic data.

As a result, the data correlates better with archeological records:


One of the most striking results was obtained for the Sardinian sample (Fig. 1). Semino et al.'s ordination of the haplotype frequencies showed the Sardinian sample clustering with Greek and Albanian samples, far removed from the Basque samples. That result appeared at odds with archaeological data that suggest a limited Neolithic immigration in Sardinia (e.g., ref. 32). Conversely, in Fig. 1a, Sardinia appears as an outlier with a significantly high proportion of Palaeolithic genes. This result suggests that the Y-chromosome differentiation observed between Basques and Sardinians today is due to drift from common Palaeolithic ancestors, with little input of genes from the Near East, rather than to a greater Neolithic immigration in Sardinia. This result shows the importance in separating drift from admixture in the analysis of ancient demographic events.

And it also supports Cavalli-Sforza's original demic diffusion model:


This finding leads us to reject a predominantly cultural transmission of agriculture. Instead, we argue that the demic diffusion model introduced by Ammerman and Cavalli-Sforza [Ammerman, A. J. & Cavalli-Sforza, L. L. (1984) The Neolithic Transition and the Genetics of Populations in Europe (Princeton Univ. Press, Princeton)] captures the major features of this dramatic episode in European prehistory.

...

Europe-wide gradients of allele frequencies have repeatedly been described since the early work of Ammerman and Cavalli-Sforza (1, 5, 12, 13, 28). They were originally interpreted as a consequence of the admixture between low density local hunter-gatherers and the large numbers of new-coming farmers from the Near East.

...

Our assessment of the demographic impact of the Neolithic expansion into Europe is largely independent from, but appears consistent with, archaeological evidence, simulations, and classical studies of allele frequencies. Despite some reports of its demise, the original model proposed by Ammerman and Cavalli-Sforza is more alive than ever.

Finally, the study's results have been duplicated analyzing nuclear DNA:


Clines of nuclear DNA markers suggest a largely Neolithic ancestry of the European gene pool

Comparisons between archaeological findings and allele frequencies at protein loci suggest that most genes of current Europeans descend from populations that have been expanding in Europe in the last 10,000 years, in the Neolithic period. Recent mitochondrial data have been interpreted as indicating a much older, Paleolithic ancestry. In a spatial autocorrelation study at seven hypervariable loci in Europe (four microsatellites, two larger, tandem-repeat loci, and a sequence polymorphism) broad clinal patterns of DNA variation were recognized. The observed clines closely match those described at the protein level, in agreement with a possible Near Eastern origin for the ancestral population. Separation times between populations were estimated on the basis of a stepwise mutation model. Even assuming low mutation rates and long generation times, we found no evidence for population splits older than 10,000 years, with the predictable exception of Saami (Lapps). The simplest interpretation of these results is that the current nuclear gene pool largely reflects the westward and northward expansion of a Neolithic group. This conclusion is now supported by purely genetic evidence on the levels and patterns of microsatellite diversity, rather than by correlations of biological and nonbiological data. We argue that many mitochondrial lineages whose origin has been traced back to the Paleolithic period probably reached Europe at a later time.

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=21201&rendertype=abstract

Vetinari
Friday, May 28th, 2004, 03:08 PM
I doubt the estimates are wrong. They're not even based on haplogroup frequencies, so Barac's criticism is moot. They were derived using a method that Chikhi et al. argue convincingly is vastly more accurate:


Neolithic DNA was largely confined to south-eastern European areas such as southern Italy and Greece. All Chikhi did was to take Semino's data and use some fancy statistical program to try to back up his claims. Haplogroups R and I have been in Europe since the Ice Age while Neolithic lineages such as Haplogroups E and J have only entered Europe with the development of agriculture and are mostly confined to south-eastern Europe. Check out the link below for more information on Haplogroup I:

http://www.freewebs.com/vetinari/hapi.pdf

The Oracle
Monday, May 31st, 2004, 01:32 PM
Sorry, but you haven't proven anything. First of all, you're still discussing haplogroups, which aren't relevant to the data in question. Secondly, neither one of us is qualified to question Chikhi's methods. And third, Chikhi actually discovered serious flaws in Semino's data (e.g. in the case of Sardinia) which can't be ignored.

Obviously, you favor the Semino data because you view Neolithic ancestry as "nonwhite." The Chikhi studies may not be the absolute and final word on the subject, but they certainly reflect a trend back toward the original demic diffusion model. So you'd better be prepared to modify your views on Neolithic ancestry.

Vetinari
Tuesday, June 1st, 2004, 05:08 PM
Sorry, but you haven't proven anything. First of all, you're still discussing haplogroups, which aren't relevant to the data in question. Secondly, neither one of us is qualified to question Chikhi's methods. And third, Chikhi actually discovered serious flaws in Semino's data (e.g. in the case of Sardinia) which can't be ignored.

Obviously, you favor the Semino data because you view Neolithic ancestry as "nonwhite." The Chikhi studies may not be the absolute and final word on the subject, but they certainly reflect a trend back toward the original demic diffusion model. So you'd better be prepared to modify your views on Neolithic ancestry.

First of all, I wan't the one questioning Chikhi. It was another scientist. Secondly, what flaws in Semiono's data did he find? All I can see is that he took a fancy statistics program and used it to get the results that he wanted. If you look at the research, Y-chromosome Haplogroups such as R and I are rare in the Middle East but common in Europe which indicates that they did not originate in that region. Also, Haplogroups are relevant to the issue at hand since Chikhi was using Semino's data which you claim was flawed. The only significant level of Neolithic Middle Eastern ancestry in Europe can be found in southern Italy, Greece and surrounding areas. Neolithic Middle Eastern ancestry is rare in northern and western Europe.

The Oracle
Wednesday, June 9th, 2004, 09:45 AM
what flaws in Semiono's data did he find?

If you had bothered to read the study, or at least my post containing relevant quotes, you'd know the answer to that question.

Vetinari
Wednesday, June 9th, 2004, 07:01 PM
If you had bothered to read the study, or at least my post containing relevant quotes, you'd know the answer to that question.

Actually I did. All Chikhi did was use a fancy statistical program on Semino's data. Semino's data dealt with M173 and M170 which are now known as Haplogroups R and I respectively. While both are common in northern and western Europe they are much rarer in the Middle East. In fact, Haplogroup R is more common in central Asia than it is in the Middle East. Middle Eastern populations are more closely related to North Africans than they are to either Northern or Western Europeans.