August 26, 2009

Demic diffusion of agriculture into Europe supported by craniometric data

A previous article by Pinhasi et al. Tracing the Origin and Spread of Agriculture in Europe

UPDATE (Sep 4):

A new ancient mtDNA study supports the conclusion that LBK agriculturalists were not related to the Mesolithic population.

PLoS ONE 4(8): e6747. doi:10.1371/journal.pone.0006747

Craniometric Data Supports Demic Diffusion Model for the Spread of Agriculture into Europe

Ron Pinhasi, Noreen von Cramon-Taubadel

Abstract

Background

The spread of agriculture into Europe and the ancestry of the first European farmers have been subjects of debate and controversy among geneticists, archaeologists, linguists and anthropologists. Debates have centred on the extent to which the transition was associated with the active migration of people as opposed to the diffusion of cultural practices. Recent studies have shown that patterns of human cranial shape variation can be employed as a reliable proxy for the neutral genetic relationships of human populations.

Methodology/Principal Findings

Here, we employ measurements of Mesolithic (hunter-gatherers) and Neolithic (farmers) crania from Southwest Asia and Europe to test several alternative population dispersal and hunter-farmer gene-flow models. We base our alternative hypothetical models on a null evolutionary model of isolation-by-geographic and temporal distance. Partial Mantel tests were used to assess the congruence between craniometric distance and each of the geographic model matrices, while controlling for temporal distance. Our results demonstrate that the craniometric data fit a model of continuous dispersal of people (and their genes) from Southwest Asia to Europe significantly better than a null model of cultural diffusion.

Conclusions/Significance

Therefore, this study does not support the assertion that farming in Europe solely involved the adoption of technologies and ideas from Southwest Asia by indigenous Mesolithic hunter-gatherers. Moreover, the results highlight the utility of craniometric data for assessing patterns of past population dispersal and gene flow.

Link

5 comments:

Gioiello said...

I consider reassuring the authors’ words: “The authors have no support or funding to report” and certainly Romans were malicious when spoke of “excusatio non petita…”, but we have day by day a chain of papers carried always from the same wind. That wind we in Italy call “libeccio”, even though Libya in this case has no guilty. More than a “libeccio” it seems rather a “khamsin”, which makes the climate unbearable in these last weeks and ruinous flames on Greece. Then after having demolished a paper, really bad written and worse thought, cheer up: let’s read.

Gioiello said...

What a fright it gave me! But no care. 1) The demic diffusion touched only the Balkans and Central Europe, but it is demonstrated that there isn’t continuity between Neolithic farmers and to-day population. Then this study is purely academic and doesn’t concern us Europeans. 2) Anyway they started from Central Anatolia, and that we knew. Hg. J2 etc. from somewhere did come. 3) And then the reassuring conclusion: “Given that the biological matrices employed here were generated from relatively small samples (10–31 crania per OTU) there is an error inherent to the estimation of the biological relationships between OTUs. Therefore, we add the caveat that all significance values associated with Mantel and Dow-Cheverud tests reported here are minimum values”(page 7).
The I can continue to cultivate my dream of an Italian refugium of R1b1b2!

Maju said...

The study seems to compare apples and oranges for the most part:

1. The Epipaleolithic/Mesolithic populations are, excepted two or three, from very distant regions to those studied for the Neolithic. Somebody explains me why the Epipaleolithic of Portugal is not compared with the Neolithic of Portugal, for example.

2. It fails to compare with modern people of the same areas, something that should be quite easy.

Anyhow for what is worth, the relevant graph is fig 3 and that suggests that:

1. Epipaloelithic/Mesolithic Palestinians (Natufian) and Central Europeans were almost identical.

2. Epipaleolithic Balcanic, Western and Northeastern Europeans were almost identical.

3. Neolithic Anatolians, Balcanic and Central Europeans cluster somewhat. But the core of the cluster is not Catal Huyuk or Greece but the so called "Aceramic" (PPNA/B?), AVK and LBK East (the core of Danubian culture) and LBK North.

These groupings make little sense: what do Natufians and Epipaleolithic Central Europeans had in common? What did PPNA or evene PPNB had in common with Polish Neolithic? What did Western and Eastern Epipaleolithic Europeans had in common to the exclusion of Central Europeans? Again craniometry appears more confusing than providing valid answers.

And has anybody even considered that nutritional or other cultural practices could have influenced this craniometric variability? En fin...

eurologist said...

Seems like a typical garbage in, garbage out paper.

I had to laugh when I read this:

These results are in agreement with most genetic studies which report a considerable genetic contribution of SW Asian farmers to the modern European gene pool

I wonder what they mean by "considerable?" A few percent?

I also agree on the strong effect of nutrition on cranial shapes that seemingly was not taken into account.

Ponto said...

Don't accept the paradigm, the Paleolithic/Neolithic belief of the peopling of Europe.

The differences in craniometric data is interesting, but does it mean anything or prove anything?

In many places in Europe you can find differences in craniometric measurements in populations that live in certain areas over separated my time of occupation. It does not prove those people were not their descendants or closely related.

DNA studies of the remains of Neolithic age, Neolithic settlements show that the dna profile varies significantly from modern Europeans whether Northern or Southern. Inhabitants of the Basque country some thousands of years ago are quite different from modern Basques. Changes occur with time, head shape and bone thickness is just as likely to change as the frequencies of certain dna haplogroups.