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Template:Totally disputed This section describes demographic and genetic flow into Europe. For a broader, more detailed view of Human migrations, see that article.

Paleolithic

The prehistory of the European peoples can be traced by the examination of archaeological sites, linguistic studies, and by the examination of the sequence of bases of DNA of the people who live in Europe now, or from recovered ancient DNA . Much of this research is ongoing, with discoveries still being continually made, and theories rise and fall. Even the broad consensus, based initially upon the analysis of mitochondrial DNA, but confirmed by Y-chromosome lineages and most recently by autosomal polymorphisms (indels, Alu sequences, SNPs, etc.), that early man migrated out of Africa 65-85,000 years ago has its critics ,

The human species (homo sapiens) began to colonize Europe from Africa about 35 millennia ago, arriving along two major channels on either side of the Black Sea . Very quickly—by about 25 millenia ago—the prior inhabitants (our cousin species H. neanderthalensis) were either killed off or absorbed into the population and ultimately became extinct . About 22 millennia ago, glaciers began to cover Europe, rendering much of the region uninhabitable . The inhabitants fled to areas along the northern Mediterranean coastline. When the glaciers receded about 16 millennia ago, the populations that had taken refuge were joined by many other waves of peoples from Asia and Africa to re-colonize the newly inhabitable region , . Their descendants became the hunter-gatherers who occupied Europe until the advent of agriculture . Then, about eight millennia ago, farming spread from Asia throughout Europe, bringing the Indo-European family of languages along with them the new technology .

Indo-Europeans

Theories about the origins of the Indo-European language center around a hypothetical Proto-Indo-European people, who are traced, in the Kurgan hypothesis, to somewhere north of the Black Sea, or possibly Anatolia around 6000–4000 BCE. They domesticated the horse, and spread their culture and genes across Europe. To what extent they replaced the indigenous Mesolithic peoples is debated, but a consensus has been reached that technology and language transfer played a more important role in this process than actual gene-flow.

The Basques of the Pyrenees and the Saami of Finland both have distinctive pre-Indo-European genetic markers and the Basques speak a non-Indo-European language , though it is possible their language may derive from post-Paleolithic but pre-Indo-European migration. (Dene-Caucasian and Uralic hypotheses) Some neighboring non-Basque areas of Northern Spain, as well as the Welsh and especially Irish, have also been found to share high levels of these genetic markers with the Basques . In fact, these Basque genetic markers, called Hg R1b, are predominant in all of Western Europe, with the approximate following values: Basques and Irish about 95%, Welsh about 85%, Scots about 75%. Non-Basque Spaniards and Portuguese about 70%. The English and Belgians about 60%. The French and Danes about 55%. These genetic markers represent the largest genetic marker in other European countries like Germany or Italy, although with figures of less than 50%. In conclusion, the so-called R1b genetic family is the most numerous in Europe, especially in Western Europe.1 2 3 4

Asiatic tribes

Over the next six millennia, Europe was repeatedly swept by successive waves of settlers and invaders from central and eastern Asia. Asian autosomal DNA makes an important contribution to the gene pools of Eastern Europe and parts of Scandinavia, present at frequencies ranging from almost 50% in Lapland to between 7 and 13% in Finland, Russia and Hungary. No country or population is completely absent of these markers, which steadily decline from the Urals towards the western Europe. West of the Urals these markers increase in frequency sharply. Contrary to some older theories, Finnish speakers are not mainly Asiatic people, but are genetically closer to their Scandinavian and Baltic neighbours, who, like many other European populations also have some proportion of the same DNA markers. The closest relatives of Finns (and probably other European Finnic peoples) are the Baltic peoples. (L. Cavalli-Sforza, Menozzi, Piazza The history of geography of human genes (1994)) Huns, Mongols and Tatars are possible sources of the admixture of the non-negligible frequency of Haplogroup N in the population. Haplogroup N is a Haplogroup of Siberian origins, but which is especially common in Eastern Europe.

An interesting case is the genetic marker known as Haplogroup R1a. Although it is believed to be of European Paleolithic origins and is very frequent in Northern, Central and Eastern Europe, it is also one of the most important genetic markers to be found in numerous Asian populations and in India and Pakistan.

North and Northeast African influences

There are a number of genetic markers which are characteristic of Horn African and North African populations which are to be found in European populations signifying ancient and modern population movements across the Mediterranean. These markers are to be found particularly in Mediterranean Europe but some are also prevalent, at low levels, throughout the continent.

The general parent Y-chromosome Haplogroup E3b, originating in modern day Somalia, is by far the most common in North and Northeast Africa, and is present throughout the majority of Europe, particularly in Mediterranean and South Eastern Europe, reaching its highest concentration in Greece and the Balkan region, but also with an important presence in other countries such as Hungary, Italy, Iberia and Austria. . Nevertheless, the presence of haplogroup E3b is principally the result of Neolithic migrations from the Horn of Africa across the Bosphorous rather than of more recent exchanges across the Mediterranean. mtDNA

However, Y-chromosome haplotype E-M81, a derivative of Haplotype E3b, is specific to North African populations and absent in Europe except for Iberia (Spain and Portugal) and the absence of microsatellite variation suggests a very recent arrival from North Africa consistent with historical exchanges across the Mediterranean during the period of Islamic expansion. Genetic studies on Iberian populations also show that North African sequences (haplogroup U6) and sub-Saharan sequences (Haplogroup L), present values which are a little higher than those generally observed in Europe, although very low levels of Haplotype U6 have also been detected in Sicily. It happens also to be a characteristic genetic marker of the Saami populations of Northern Scandinavia. It is difficult to ascertain that U6's presence is the consequence of Islam's expansion in Europe during the Middle Ages, particularly because it is more frequent in the north of the peninsula rather than in the south. It may also be the result of neolithic expansion from North Africa. On the other hand, the distribution of mtDNA Haplogroup L, on the other hand, is consistent with modern historical data, being more frequent in Iberia than in the rest of Europe and more frequent in the south of the peninsula than in the north. Islamic domination, as well as the slave trade, is likely to have been a factor leading to its presence in some modern-day Southern Iberian populations. Haplotype 5 (p49/TaqI), common in Morocco, is also found in the Iberian peninsula, and a decreasing North-South cline of frequency clearly establishes a gene flow from North Africa towards Iberia which is also consistent with Moorish presence in the peninsula.. It should be noted though that said study takes into account only one genetic marker. Other studies that take into account multiple pieces of research and up to eight different genetic markers, including autosomal, mitocondrial and Y-chromosome DNA, have come to a different conclusion as to the extent of this influence. See IberiaS (Spain) in the European context.

In fact this article comes to the following conclusion:

In figure 3, no significant correlation is apparent between North African admixture and geography. Genetic exchanges across the Mediterranean Sea, and especially in its western-most part where the geographic distance between continents is smallest (Spain), seem to have been limited or very limited (Simoni et al. 1999; Bosch et al. 2001).

Sub-Saharan African slaves

Finally, aside from E3b, sub-Saharan African DNA is scattered throughout the European continent. Not every population has been studied yet, but enough have so that a picture is starting to emerge. The amount of black admixture in Europe today ranges from a few percent in Iberia to almost nil around the Baltic. It seems to show a decreasing cline from the southwest to the northeast, which corresponds with the areas most affected by the African slave trade.

According to a summary study by Pereira et al. 2005, sub-Saharan mtDNA L haplogroups were found at rates of 0.62% in a German-Danish sample, 1% in the British, 3.83% in Iberians (Portuguese and Spanish), 2.38% in Albanians, 2.86% in Sardinians and 0.94% in Sicilians.

Sub-Saharan African Y-chromosomes are much less common in Europe, for the reasons discussed above. However, Haplogroups E(xE3b) and Haplogroup A spread to Europe due to migrations from Northeast Africa, rather than the slave trade. Haplotype A has been detected in Portugal (3%), Spain (0.42%), Germany (2%), Austria (0.78%), France (2.5% in a very small sample), Italy (0.45%), Sardinia (1.6%) and Greece (0.27%). By contrast, North Africans have about 5% paternal West African admixture, and are about of 75% paternal East African descent

For a global perspective on this topic, see Atlas of the Human Journey, World Haplogroups Maps, Origins of Europeans and Genetic Structure of Human Populations.

Footnotes

1. Genomics refutes an exclusively African origin of humans' (pdf) Vinayak Eswaran, Henry Harpending, Alan R. Rogers, Journal of Human Evolution (2005)
2. 'Deep Haplotype Divergence and Long-Range Linkage Disequilibrium at Xp21.1 Provide Evidence That Humans Descend From a Structured Ancestral Population' (first genetic evidence that statistically rejects the null hypothesis that our species descends from a single, historically panmictic population), Daniel Garrigan, Zahra Mobasher, Sarah B. Kingan, Jason A. Wilder, and Michael F. Hammer, University of Arizona, Tucson, Genetics, Vol. 170, 1849-1856, August 2005
3. Richard G. Klein (March 2003). "PALEOANTHROPOLOGY: Whither the Neanderthals?". Science 299 (5612): 1525-1527. DOI:10.1126/science.1082025.
4. Antonio Torroni et al., "A Signal, from human mtDNA , of Postgalcian Recolonization in Europe, Am. J. Human Gen.69:844-852 (2001)
5. Ornella Semin et al., The Genetic Legacy of Paleolithic Homo Sapiens Sapiens in Extant Europeans: A Y Chromosome Perspective Science 290:1155-1159, 2000.
6. Nicholas Wade, "Before the Dawn" ISBN 15943200793, ch. 10.
7. See Bryan Sykes, The Seven Daughters of Eve, 1st American ed. (New York: Norton, 2001) for an entertaining account of how this consensus was reached. For historical reasons, in the 1980s mtDNA researchers believed that the Indo-European expansion was overwhelmingly a spread of technology and language, not of genes, while the those who studied Y-chromosome lineages believed the opposite. Gradually the mtDNA guys (Sykes) admitted more physical migration into their scenarios, while the Y folks (Peter Underhill) accepted more technology-copying. Eventually, both groups independently reached a 20% Neolithic - 80% Paleolithic ratio of genetic contribution to today's European population. The mtDNA vs. Y discrepancy is explained by noting that in such conquest-based migrations, a common pattern is invading foreign males producing offspring with indigenous females, though significant numbers of females of the spreading culture would also arrive with post-conquest settlers.
8. Guglielmino et al. 1990, Rosenberg et al. 2002 and Cavalli-Sforza 1997
9. ^ *Semino et al. (2004) Origin, Diffusion, and Differentiation of Y-Chromosome Haplogroups E and J: Inferences on the Neolithization of Europe and Later Migratory Events in the Mediterranean Area
10. Pereira et al. 2005 (view the specific data here)
11. Cruciani et al. 2004, Flores et al. 2004, Brion et al. 2005, Brion et al. 2004, Rosser et al. 2000, Semino et al. 2004, and DiGiacomo et al. 2003
12. Bosch et al. 2001 High-Resolution Analysis of Human Y-Chromosome Variation Shows a Sharp Discontinuity and Limited Gene Flow between Northwestern Africa and the Iberian Peninsula