Genetic history of Italy

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According to archaeological records and historical documentation, Italy has been a melting point for populations of different geographical and ethnic matrices. Although Italy has been a favorite subject for numerous population genetic studies, genetic patterns have never been analyzed comprehensively, including uniparental and autosomal markers throughout the country.1

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).

In 2008, Dutch geneticists determined that Italy is one of the last two remaining genetic islands in Europe (the other being Finland.) This is due in part to the presence of the Alpine mountain chain which, over the centuries, has prevented large migration flows aimed at colonizing the Italian lands.2

Historical population of Italy

  • During the Neolithic farming is introduced by people from the east and the first villages are built, weapons become more sophisticated and the first objects in clay are produced.
  • In the late Neolithic era the use of copper spreads and villages are built over piles near 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 invaded Italy, the most significant was that of the Lombards, who will try to unify politically the "Boot of Italy".

Y-DNA genetic diversity

Y-haplogroups in Europe.

In most of the Po Valley and Emilia-Romagna, a majority of the population belongs to Haplogroup R1b. This percentage lowers at the extreme south of Italy in Sicily (30%).

A Università 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 along 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.67

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

Migration High Medieval Y-DNA

Migrations that occurred on Italian soil from the fall of the Roman Empire until 1000 AD have probably not significantly altered the gene pool of the Italian people.9page needed Despite the lengthy Goth and Lombard presence in Italy, it is estimated that the I1 haplogroup associated with the Germanic peoples is only present among Italians in the north in the order of 2-3% and from 1 to 1.5% among Italians in the south.10

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 11 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 then wanders around 5-10%.

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%.121314

Genetic composition of Italians mtDNA

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.citation needed

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.15

A study in 2012 by Brisighelli "et al." stated that an analysis of ancestral informative markers "as carried out in the present study indicated that Italy shows a very minor sub-Saharan African component that is, however, slightly higher than non-Mediterranean Europe." Discussing sub-Saharan African mtDNAs the study states that these indicate that a significant proportion of these lineages could have arrived in Italy more than 10,000 years ago; therefore, their presence in Europe does not necessarily date to the time of the Roman Empire, the Atlantic slave trade or to modern migration."16 These mtDNAs by Brisighelli "et al." were reported with the given results as "Mitochondrial DNA haplotypes of African origin are mainly represented by haplogroups M1 (0.3%), U6 (0.8%) and L (1.2%)" for the 583 samples tested.17

Close genetic similarity between Ashkenazi Jews and Italians has been noted frequently in genetic studies.18192021222324

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 9,000 and 7,000 years ago, 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.25

See also

References

  1. ^ http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050794#pone-0050794-g002
  2. ^ "Genetic Map of Europe". New York Times. August 2008. Retrieved 25 February 2014. 
  3. ^ Siiri Rootsi: Y-Chromosome haplogroup I prehistoric gene flow in Europe, UDK 902(4)"631/634":577.2, Documenta Prehistorica XXXIII (2006)
  4. ^ [1]dead link Culture del bronzo recente in Italia settentrionale e loro rapporti con la "cultura dei campi di urne"
  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. ^ http://books.google.com/books?id=FrwNcwKaUKoC&printsec=frontcover&dq=history+of+human+genes&hl=en&ei=yQtITqPZDoOcgQfc28GsBg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CCoQ6AEwAA#v=snippet&q=roman&f=false
  10. ^ http://books.google.com/books?id=FrwNcwKaUKoC&printsec=frontcover&dq=history+of+human+genes&hl=en&ei=yQtITqPZDoOcgQfc28GsBg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CCoQ6AEwAA#v=snippet&q=roman&f=false
  11. ^ [2] Y-chromosome Short Tandem Repeat DYS458.2 Non-consensus Alleles Occur Independently in Both Binary Haplogroups J1-M267 and R1b3- M405
  12. ^ "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
  13. ^ 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
  14. ^ Table 1 Historically introduced NW African types in Italy and Iberia
  15. ^ 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
  16. ^ http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050794#pone-0050794-g002
  17. ^ http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050794#pone-0050794-g002
  18. ^ Zoossmann-Diskin, Avshalom (2010). "The origin of Eastern European Jews revealed by autosomal, sex chromosomal and mtDNA polymorphisms". Biol Direct 5 (57): 57. doi:10.1186/1745-6150-5-57. PMC 2964539. PMID 20925954 
  19. ^ Did Modern Jews Originate in Italy? Michael Balter, ScienceNOW, 8 October 2013
  20. ^ Genetic Roots of the Ashkenazi Jews
  21. ^ M. D. Costa and 16 others (2013). "A substantial prehistoric European ancestry amongst Ashkenazi maternal lineages". Nature Communications 4. doi:10.1038/ncomms3543. 
  22. ^ Rosenberg et al. 2002,Bauchet et al. 2007
  23. ^ C.Tian et al. 2009, European Population Genetic Substructure: Further Definition of Ancestry Informative Markers for Distinguishing among Diverse European Ethnic Groups
  24. ^ Chao Tian et al. 2009, Paired Fst values for European populations
  25. ^ [3] 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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