Haplogroup J2 (Y-DNA)

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In human genetics, Haplogroup J2 (M172) is a Y-chromosome haplogroup which is a subdivision of haplogroup J.

Haplogroup J2 is widely believed to be associated with the spread of agriculture from the northern Fertile Crescent, the Levant, and Anatolia [2],[3]. This connection is supported by its age (8,500 +/- 3,500 thousand years ago) [2], which is very close to the beginning of the Neolithic, its distribution, which is centered in West Asia and Southeastern Europe, its association with the presence of Neolithic archaeological artifacts, such as figurines and painted pottery [4], and its association with annual [precipitation] interpreted as evidence that J2, and in particular its J2a-M410 subclade belonged to the agricultural innovators who followed the rainfall[5].

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[edit] Distribution

subclades of J2 Haplogroup
subclades of J2 Haplogroup

Haplogroup J2 is found mainly in the northern Fertile Crescent, the Mediterranean (including Southern Europe and North Africa), the Iranian plateau and Central Asia.[1], in Greece and Italy and the Iberian Peninsula[6], and more frequently in Province of Kurdistan 28% of the population (semino et al),Iraq 25% of the population,, in Lebanon 25% of the population, in Jordan, in Syria , Israel in [2], in Turkey [1], and in the southern Caucasus region [7]. According to Semino et al and the National Geographic Genographic Project, the frequency of haplogroup J2 generally declines as one moves away from the Northern fertile crescent. Haplogroup J2 is carried by 6% of Europeans and its frequency drops dramatically as one moves northward away from the Mediterranean. Sephardic Jews have roughly twice as much J2 as J1 and Ashkenazi Jews have a near equal proportion of J1 and J2 haplogroup markers. (Behar et al.) J2 subclades are also found in the South Caucasus (Georgia, Armenia, Azerbaijan), Iran, Central Asia, and South Asia.

Another important fact about the distribution of Haplogroup J2 is that it appears to have dispersed from a Middle Eastern homeland to the west through a primarily maritime or littoral route, as it is found in high concentrations among the populations of the coasts of the Mediterranean Sea in both Eurasia and Africa, and particularly along the coasts of the eastern Mediterranean in Europe. This distribution may be more consonant with a Neolithic or post-Neolithic maritime dispersal from the Middle East, such as through Greek colonization[8] or even Phoenician[citation needed] commercial and colonial activities.

In Italy, J2 is found in about 23% of southern Italians, and 17% of central-north Italians[11]. Turkey is one of the countries with major J2 population. 24% of Turkish men are J2 according to a recent study [1], with regional frequencies ranging between 10% and 31%. Combined with J1, one third of the total population of Turkish people belongs to Haplogroup J. In neighboring Greece, as in Italy J2 is also common, with regional frequencies ranging between 11% and 46%.

Typically, modern populations of the southern Middle East (especially Arabic-speaking ones) have a higher frequency of the related haplogroup J1, whereas the great majority of Haplogroup J representatives among the populations of the Northern Middle East, Lebanon, Europe, and India belong to the subclade J2. Haplogroup J2 has been shown to have a more northerly distribution in the Middle East when compared to its brother haplogroup, J1, which has a more southerly distribution. This suggests that, if the occurrence of Haplogroup J among modern populations of Europe, Central Asia, and South Asia does reflect Neolithic demic diffusion from the Middle East, the source population is more likely to have originated from Anatolia, the Levant or northern Mesopotamia than from regions further south.

A March 2008 study found that haplogroup J2a was linked to populations on ancient Crete by genetics researchers who examined the relationship between Anatolian, Greek, and Cretan populations.[2] Haplogroup J2b-M12 was associated with Neolithic Greece (ca. 8500 - 4300 BCE) and was reported to be found in modern Crete (3.1%) and mainland Greece (Macedonia 7.0%, Thessaly 8.8%, Argolis 1.8%).[3]

[edit] Subdivisions

Haplogroup J2 is subdivided into two complementary sub-haplogroups: J2a, defined by the M410 genetic marker, and J2b, defined by the M12 genetic marker. A subclade of haplogroup J2a, defined by the M92 marker has been implicated in the ancient Greek colonization [9].

The subclades of Haplogroup J2 with their defining mutation, according to the 2006 ISOGG tree:

  • J2 (M172)
    • J2*
    • J2a (M410)
      • J2a*
      • J2a1 (DYS413≤18)
        • J2a1*
        • J2a1a (M47, M322)
        • J2a1b (M67 (S51))
          • J2a1b*
          • J2a1b1 (M92, M260)
            • J2a1b1*
            • J2a1b1a (M327)
          • J2a1b2 (M163, M166)
        • J2a1c (M68)
        • J2a1d (M137)
        • J2a1e (M158)
        • J2a1f (M289)
        • J2a1g (M318)
        • J2a1h (M319)
        • J2a1i (M339)
        • J2a1j (M419)
        • J2a1k (DYS445≤7)
      • J2a2 (M340)
    • J2b (M12, M314, M221)
      • J2b*
      • J2b1 (M102)
        • J2b1*
        • J2b1a (M241)
          • J2b1a*
          • J2b1a1 (M99)
          • J2b1a2 (M280)
          • J2b1a3 (M321)
        • J2b1b (M205)


J2 (M-172) is divided into eight sub-Haplogroups defined by mutations M12/M102, M47, M67/M92, M68, M137, M158, M339, and M340 (see Diagram), four of which occur at informative frequencies[1][2], The less-heterogeneous J2 (J-M172), which occurs as frequently as J1( J-M267) in some Middle Eastern populations, is the more prevalent in Europe.

J-M102 illustrates population expansions from the southern Balkans. J-M67 is most frequent in the Caucasus (Georgia) , and J-M92, which indicates affinity between Anatolia and southern Italy. Whereas J-M67* and J-M92 show higher frequencies and variances in Europe and in Turkey. Likewise, J-M47 and J-M68 characterize very few Near Eastern and Asian samples.[1]

[edit] References

  1. ^ a b c Semino et Al., 2004[1]
  2. ^ See the Wikipedia article: Genetics of the Ancient World
  3. ^ King, R. J.; Ozcan, S. S., Carter, T., Kalfoglu, E., Atasoy, S., Triantaphyllidis, C., Kouvatsi, A., Lin, A. A., Chow, C-E. T., Zhivotovsky, L. A., Michalodimitrakis, M., Underhill, P. A., (2008). "Differential Y-chromosome Anatolian Influences on the Greek and Cretan Neolithic". Annals of Human Genetics 72 Issue 2 March 2008: 205–214. doi:10.1111/j.1469-1809.2007.00414.x. 
  1. ^  C. Cinnioglu et al. (2004), Excavating Y-chromosome haplotype strata in Anatolia, Human Genetics 114(2):127-48.
  2. ^  O. 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, American Journal of Human Genetics 74(5):1023-34.
  3. ^  R. King and P.A. Underhill (2002), Congruent distribution of Neolithic painted pottery and ceramic figurines with Y-chromosome lineages, Antiquity 76:704-714
  4. ^  F. Di Giacomo et al. (2003), Clinal patterns of human Y chromosomal diversity in continental Italy and Greece are dominated by drift and founder effects, Molecular Phylogenetics and Evolution 28(3):387-95.
  5. ^  I. Nasidze et al. (2003), Testing hypotheses of language replacement in the Caucasus: evidence from the Y-chromosome, Human Genetics 112(3):255-61.
  6. ^  Sanghamitra Sengupta et al. (2006), Polarity and Temporality of High-Resolution Y-Chromosome Distributions in India Identify Both Indigenous and Exogenous Expansions and Reveal Minor Genetic Influence of Central Asian Pastoralists, American Journal of Human Genetics, 78:202-221
  7. ^  Renfrew, A.C. (1987). Archaeology and Language: The Puzzle of Indo-European Origins, London: Pimlico. ISBN 0-7126-6612-5
  8. ^  A. Nebel et al. (2001), The Y chromosome pool of Jews as part of the genetic landscape of the Middle East, Americal Journal of Human Genetics 69(5):1095-112.
  9. ^  F. Di Giacomo et al. (2004), Y chromosomal haplogroup J as a signature of the post-neolithic colonization of Europe, Human Genetics 115(5):357-71.
  10. ^  J. Chiaroni et al. (2008), Correlation of annual precipitation with human Y-chromosome diversity and the emergence of Neolithic agricultural and pastoral economies in the Fertile Crescent, Antiquity Volume: 82 Number: 316 Page: 281–289
  11. ^  V. Onofri et al. (2008), Y chromosome J2 subtyping in an Italian sample: Population and forensic implications, Forensic Science International: Genetics Supplement

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