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Sunday, June 2, 2013

Genetic history of Italy

During prehistory Italy was populated by different but very similarn European groups, later collectively listed amongst the Ancient peoples of Italy, of whom the Italic one was predominant.
Not all of these various peoples were linguistically or ethnically closely related. Some of them spoke Italic languages, and others belonged to another Indo-European branch (Ligurian, Venetic, Lepontic) or were non-Indo-European (Etruscan, Raetic).
Following scientific research carried out by Dutch geneticists, Italy has proven to be one of the last two remaining genetic islands across Europe (along with Finland), this due to the presence of the Alpine mountain chain that, over the centuries, has prevented large migration flows aimed at colonizing the Italian lands[citation needed].


Historical population of Italy

  • During the Neolithic farming stable is introduced by people from the east and the first villages are built, the weapons become more sophisticated and the first objects in clay produced.
  • In the late Neolithic era the use of copper spreads and villages are built over piles near the lakes. In Sardinia, Sicily and part of "Continental Italy" the Beaker culture spreads from Western Europe.
  • With the Fall of the Roman Empire different populations of German origin intruded into Italy, the most significant was that of the Lombards, who will try to unify politically the "Boot of Italy".

Genetic composition of Italians Y-DNA

Percentages of the various Y-DNA haplogroups (male) to which belong the Italians.[3]

R1b R1a I1 I2a I2b J T G E3b
 % 49% 2,5% 2,5% 3% 1% 20% 4% 7% 11%
Haplogroups I and R1b have been present in Europe since the Paleolithic while haplogroups J, T, G, E1b1b1 have been present in Europe since the Neolithic, or in some cases possibly arrived shortly before in the Mesolithic, and R1a arrived in the Chalcolithic with the migrations of the Proto-Indo-Europeans[citation needed].

Y-DNA genetic diversity

Y-haplogroups in Europe.
In most of the Po Valley, Emilia and Romagna, more of the population belongs to Haplogroup R1b. This percentage comes in low percentages the extreme south of Italy in Sicily - 30%.
Distribution of Italian Y-chromosome DNA (Y-DNA) haplogroups by region in percentage.[4]
Region I1 I2a I2b R1a R1b G2a J2 J1 E1b1b T + (L) Q
North Italy 6% 2.5% 2.5% 3.5% 55% 2.5% 11.5% 0.5% 11% 4.5% 0%
Central Italy 3% 2% 5% 3.5% 43% 8.5% 19.5% 2% 10% 3.5% 0%
South Italy 2.5% 2.5% 2.5% 2.5% 29% 8.5% 23.5% 5% 18% 5.5% 0%
Sicily 3% 1% 1% 4.5% 30% 5.5% 26.5% 4% 17.5% 6% 1%
Sardinia 0% 37% 0% 0% 22% 15% 10% 2.5% 10% 1.5% 2%
A Universita' Cattolica del Sacro Cuore study found that while Greek colonization left little significant genetic contribution, data analysis sampling 12 sites in the Italian peninsula supported a male demic diffusion model and Neolithic admixture with Mesolithic inhabitants.[5] The results supported a distribution of genetic variation alond a north South-Axis and supported demic diffusion. South Italian samples clustered with South east and south central European samples, and Northern groups with West Europe.[6][7]
A 2004 study by Semino et al. contradicted this study, and showed that Italians in North-central regions (like Tuscany and Emilia-Romagna) had a higher concentration of J2 than their Southern counterparts. North-central had 26.9% J2, whereas Calabria (a far Southern region) had 20.0%, Sardinia had 9.7% and Sicily had 16.7%.[8] This could be because of the ancient Etruscans, who some think originated in the Near East.

Migration High Medieval Y-DNA

Migrations that occurred on Italian soil from the fall of the Roman Empire until 1000 AD have in some places caused undetermined alterations to the gene pool of the Italian people.[9] Despite the Goths and Lombards bringing much new blood to the Italians, it is estimated that the I1 haplogroup associated with the Germanic peoples is present among Italians in the north in the order of 2-3% and from 1 to 1.5% among Italians in the south.[10]
Most modern Germanic populations are not in Haplogroup I1 however, they are in Haplogroup R1b, and one SNP defined clade of R1b encompasses nearly one of every two modern males in Lombardy, and the surrounding Po Valley Germanic settlement area. This clade is defined by the SNP U-152 also known as 'S28'. The high occurrence of R1b U-152 does not occur outside of the Germanic settlement areas. The Germanic settlement region of the Po Valley is the location of the highest percentage of the U-152 SNP in any human population.[11]
Other haplotypes that could have been penetrated in Italy together with the German invaders are haplogroup R1a which belongs to 2.5% of Italians and some subclades of the R1b Haplogroup (in particular the subclade R1b1c9 that owns 3.5% of Italians [12] and is particularly widespread among the peoples of north-west Italy) but because these haplogroups are just mentioned fairly commonly in other European ethnic groups it is difficult to establish whether they have been really brought into Italy by Germanic peoples or by other peoples (e.g. Slavs). The Germanic or Nordic heritage among the Italians is not fully clear at this time from genetic evidence.
In Sicily further migrations from the Vandals, Normans and Saracens have only slightly affected the ethnic composition of the Sicilian people. The Arab civilization flourished undisturbed for nearly a century and the impact of Arab-Berber colonization occurred in a more intense way. Ultimately, the North African male contribution to Sicily was estimated between 6 and 7.5%.[13][14][15] This period was followed by centuries of Norman rule and migration into Sicily from France (Franks, Normans) and Northern and Southern Italy (Lombards, Ligurians, and Latins) that would transform Sicily into "the jewel of the Mediterranean.

Genetic composition of Italians mtDNA

Percentages of mtDNA haplogroups (female) among Italians:

H V J T U K I W X2 others
 % 33,5% 4,5% 7,5% 12% 12,5% 7% 2% 2,5% 2% 16,5%
In Italy as elsewhere in Europe the most common haplogroup is haplogroup H originated probably about 20,000 years ago in southern Europe or in the Near East. Follow the haplogroup V originated in Iberia 15,000 years ago, haplogroup J originated in the Near East or the Caucasus, W (north-east 25.000 years ago), T (Mesopotamia 17.000 years ago), U5,I (40,000 years ago in the Balkans or Greece), K (16.000 years ago in North East Europe, X2 (over 30,000 years ago in north-east Europe).[16][17]
African Haplogroup L lineages are relatively infrequent (1% or less) throughout Italy with the exception of Latium, Volterra, Basilicata and Sicily where frequencies between 2 and 3% have been found.[18]

The contribution of Italians in rebuilding Europe's mtDNA

Recent studies have shown that Italy has played an important role in the recovery of 'Western Europe" at the end of the Last glacial period. The study focused mitochondrial U5b3 haplogroup discovered that this female lineage had in fact originated in Italy and that then expanded from the Peninsula around 10,000 years ago towards Provence and the Balkans. In Provence, probably between 9000 and 7000 years, it gave rise to the haplogroup subclade U5b3a1. This subclade U5b3a1 later came from Provence to Sardinia by obsidian merchants, as it is estimated that 80% of obsidian found in France comes from Monte Arci in Sardinia reflecting the close relations that were at the time of these two regions. Still about 4% of the female population in Sardinia belongs to this haplotype.[19]

See also


  1. ^ Siiri Rootsi : Y-Chromosome haplogroup I prehistoric gene flow in Europe, UDK 902(4)"631/634":577.2, Documenta Prehistorica XXXIII (2006)
  2. ^ [1][dead link] Culture del bronzo recente in Italia settentrionale e loro rapporti con la "cultura dei campi di urne"
  3. ^ [2] Eupedia : Distribution of European Y-chromosome DNA (Y-DNA) haplogroups by region in percentage
  4. ^ [3] Eupedia : Distribution of European Y-chromosome DNA (Y-DNA) haplogroups by region in percentage. See note n° 4
  5. ^ Y chromosome genetic variation in the Italian peni... [Mol Phylogenet Evol. 2007] - PubMed result
  6. ^ Capelli, C. et al., Y chromosome genetic variation in the Italian peninsula is clinal ..., Mol. Phy-logenet. Evol. (2007), doi:10.1016/j.ympev.2006.11.030
  7. ^ The History and Geography of Human Genes Search results for "Southern Italy" on Google Books
  8. ^ Ornella Semino et al., "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," American Journal of Human Genetics 74:1023–1034, 2004.
  9. ^ The History and Geography of Human Genes Search results for "roman" on Google Books
  10. ^ [4] Phylogeography of Y-Chromosome Haplogroup I Reveals Distinct Domains of Prehistoric Gene Flow in Europe
  11. ^ [5] Phylogeography of Y-Chromosome Haplogroup I Reveals Distinct Domains of Prehistoric Gene Flow in Europe
  12. ^ [6] Y-chromosome Short Tandem Repeat DYS458.2 Non-consensus Alleles Occur Independently in Both Binary Haplogroups J1-M267 and R1b3- M405
  13. ^ "The genetic contribution of Greek chromosomes to the Sicilian gene pool is estimated to be about 37% whereas the contribution of North African populations is estimated to be around 6%.", Differential Greek and northern African migrations to Sicily are supported by genetic evidence from the Y chromosome European Journal of Human Genetics (2009) 17, 91–99; doi:10.1038/ejhg.2008.120; published online 6 August 2008
  14. ^ Moors and Saracens in Europe, estimating the medieval North African male legacy in southern Europe European Journal of Human Genetics (2009) 17, 848–852; doi:10.1038/ejhg.2008.258; published online 21 January 2009
  15. ^ Table 1 Historically introduced NW African types in Italy and Iberia
  16. ^ [7] Distribution of European mitochondrial DNA (mtDNA) haplogroups by region in percentage
  17. ^ [8] Chronological development of mtDNA haplogroups
  18. ^ 4/138=2.90% in Latium, 3/114=2.63% in Volterra, 2/92=2.20% in Basilicata and 3/154=2% in Sicily, Achilli et al.2007, Mitochondrial DNA Variation of Modern Tuscans Supports the Near Eastern Origin of Etruscans
  19. ^ [9] American Journal of Human Genetics : Mitochondrial Haplogroup U5b3: A Distant Echo of the Epipaleolithic in Italy and the Legacy of the Early Sardinians

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