View Full Version : North African genetics and recent migrations

26-10-16, 18:51
This was published in Oxford Journals, so not only don't we get to see the body of the paper, but they've even blocked the Supplement. Jeez!

The other problem is that Hellenthal, who is one of the authors, has an amazingly weak grasp of ancient history imo, and his method of dating is not without issues. So, although I think the basic breakdown is correct, I'm not sure about the dates at which these elements entered the North African genome or the reasons.

If someone has access and thinks there's good data to support their conclusions, it would be great if we could get some hints.


Lara Arauna et al:

"North Africa is characterized by its diverse cultural and linguistic groups and its genetic heterogeneity. Genomic data has shown an amalgam of components mixed since pre-Holocean times. Though no differences have been found in uniparental and classical markers between Berbers and Arabs, the two main ethnic groups in the region, the scanty genomic data available have highlighted the singularity of Berbers. We characterize the genetic heterogeneity of North African groups, focusing on the putative differences of Berbers and Arabs, and estimate migration dates. We analyze genome-wide autosomal data in five Berber and six Arab groups, and compare them to Middle Easterns, sub-Saharans, and Europeans. Haplotype-based methods show a lack of correlation between geographical and genetic populations, and a high degree of genetic heterogeneity, without strong differences between Berbers and Arabs. Berbers enclose genetically diverse groups, from isolated endogamous groups with high autochthonous component frequencies, large homozygosity runs and low effective population sizes, to admixed groups with high frequencies of sub-Saharan and Middle Eastern components. Admixture time estimates show a complex pattern of recent historical migrations, with a peak around the 7th century C.E. coincident with the Arabization of the region; sub-Saharan migrations from in the 1st century B.C. in agreement with Roman slave trade; and a strong migration in the 17th century C.E., coincident with a huge impact of the trans-Atlantic and trans-Saharan trade of sub-Saharan slaves in the Modern Era. The genetic complexity found should be taken into account when selecting reference groups in population genetics and biomedical studies."

For me one of the main take-aways is that the "Berbers" are not any more "autochthonous" than the "Arabs" of North Africa. Nor are the Berbers necessarily less SSA than the Arabs.

I'm less certain that the SSA input started because of the Roman slave trade, or that the admixture from the Near East started with the Arab conquests.

Pax Augusta
27-10-16, 01:24
This study will be presented in Paris, Musée de l'Homme, December 9, 2016. Can be this the reason?

It seems there will be other interesting papers.


27-10-16, 02:49
Given how much substructure there is in Italy, much more than in Spain, why on earth would they sample only from Napoli???

BIAGINI Simone Andrea, Solé-Morata Neus, Comas David, Calafell Francesc
Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), CEXS-UPF-PRBB, Barcelona, Catalonia, Spain
The Western Mediterranean basin represents one of the most lively core of cultural crossroads in the past, and its history is still alive in the present-day populations. Both pre-historical and historical migrations affected the genetic structure of the whole Mediterranean human groups(1): the existence of a genetic gradient across Europe has often been highlighted, and a Near East origin for most of the current Europeans has been suggested(2). So far, a large number of genetic studies have been carried out in the Mediterranean area using different markers, but no consensus has been reached on the genetic landscape of the Mediterranean populations, and often-contradictory results have been achieved(1). Because of the intricacy of its past, today identify a genetic profile of the Western Mediterranean populations is if nothing else a complex challenge.
Using the array technology, in this work we enhance the resolution on a local scale, and try to detect finer substructures related to the internal and external contributions, thus highlighting the dynamics of the peopling of this area. For this purpose, more than 1200 samples coming from all the regions surrounding the Western Mediterranean basin have been included in the study. In particular, data comes from samples we have gathered from Catalonia, the Balearic Islands, Valencia, seven regions covering most of France, and Naples, and that have been or are being typed with the Axiom®Genome-Wide Human Origins (~629K SNPs) array. The dataset is also completed with published data for Spain(3) (also with the Axiom®Genome-Wide Human Origins), Italy (llumina HumanOmni2.5 BeadChip Array, ~2.5M SNPs), and North Africa (Genome-Wide Human SNP Array 6.0, ~900K SNPs).
With this approach we aim to shed a light on the evolutionary history of the peopling of the Western Mediterranean, even considering the role of the Mediterranean Sea as a putative barrier to the gene flow, and the impact of the historical events in shaping the different human Western Mediterranean groups.

Interesting that we finally have some Phoenician genomes. However, mtDna is not going to tell us a lot about the precise signature of the Phoenicians, although it's better than nothing:

MATISOO-SMITH E.A., A.L. Gosling, J. Boocock, Y. Kurumilian, M. Guirguis, B. Costa, W. Khalil and P.A. Zalloua.
Various affiliations
Previous research, based on DNA variation in modern populations associated with Phoenician influence, identified a number of Y chromosome STR markers that were likely to have been spread across the Mediterraneanas a result of Phoenician trade networks. We now have the unique opportunity to study the genetic makeup of the original Phoenicians themselves through aDNA analyses of ancient Phoenician burials. Here we present ancient mitochondrial genome data from Phoenician and Punic tooth and bone samples collected from key archaeological sites from across the Mediterranean region including Lebanon, Sardinia, Spain and Tunisia. We investigate the patterns of genetic variation of the Phoenicians to identify their origins and track their settlement patterns in the Mediterranean and possibly beyond."

Oh God, we've been spoiled. STRs for autosomal analysis???

SERVENTI Patrizia1,2, Chiara Panicucci1, Roberta Bodega1,2, Sara De Fanti2, Antonino Vazzana1, Chiara Delpino3, Stefania Sarno2, Manuel Fondevila Alvarez4, Francesca Brisighelli5, Beniamino Trombetta6, Donata Luiselli2, Giorgio Gruppioni1, Elisabetta Cilli1.
1 Department of Cultural Heritage, University of Bologna, Ravenna, Italy.
2 Department of Biological, Geological and Environmental Sciences, University of Bologna, Bologna, Italy.
3 Superintendence of Archaeological Heritage of Marche region.
4 Instituto de Ciencias Forenses "Luis Concheiro", University of Santiago de Compostela, Santiago de Compostela, Galicia, Spain.
5 Sezione di Medicina Legale - Istituto di Sanità Pubblica, Università Cattolica del Sacro Cuore, Roma, Italy.
6 Department of Biology and Biotechnology "Charles Darwin", Sapienza University, Rome, Italy.
During the Iron Age, in Italy, the archaeological data provide documentary evidence of the appearance of the first communities with a strong and well defined cultural identities.
At the moment, only few studies report genetic data about the Italian populations of this period and, in particular, the Piceni have never been studied. The traditional ethnogenesis describes the “Picenum Culture” as a pre-Roman population who lived in the northern Adriatic coastal plain of Italy.
A pilot research project, based on both genetic and archaeological approaches, has been started in the Novilara necropolis (dated at 8th-7thcentury BC) localized in the Marche region (central Italy). This archaeological site represents an exceptional evidence due to the presence of more than 300 graves excavated so far, characterized by abundance of grave goods and also a good conservation status of the skeletal remains. To shed light on the ancient genetic diversity of Italy of this period, the HVS-1 region of mitochondrial DNA (mtDNA) in a first set of 27 individuals from Novilara necropolis was examined by high-coverage next-generation sequencing (NGS). Typical ancient DNA damage pattern in the analysed sequences and their comparison with those of the researchers involved in this project confirm the authenticity of the obtained data. Moreover, we performed a forensic analysis on these same individuals obtaining partial profiles for both autosomal STRs (Globalfiler PCR Amplification kit and Powerplex ESX 17 System) and Indels (Investigator DIPplex Kit).
With the combination of these data, we used genetic tests in order to establish the possible kinship relationships among the individuals here analysed. By these analyses, we will try to be validate the archaeological technique of seriation based on the analysis of the material culture, and to understand the contribution of the Piceni population in shaping the modern Italian gene pool."

27-10-16, 09:36
The peak of SSA admix in modern North Africans has mostly to do with Arab slave trade, Romans at best used Nubians not Black Africans imo, in Egypt the Nubians mixed with locals in very old times though.