R1a (R-M420) The split of R1a (M420) is computed to ca 25,000 years ago (95% CI: 21, 300–29, 000 BP), or roughly the
Last Glacial Maximum. A large study performed in 2014 (Underhill et al. 2015), using 16,244 individuals from over 126 populations from across Eurasia, concluded that there was compelling evidence that "the initial episodes of haplogroup R1a diversification likely occurred in the vicinity of present-day
Iran." The subclade M417 (R1a1a1) diversified ca. 5,800 years ago. The distribution of M417-subclades R1-Z282 (including R1-Z280) in Central- and Eastern Europe and R1-Z93 in Asia suggests that R1a1a diversified within the
Eurasian Steppes or the
Middle East and
Caucasus region. The place of origin of these subclades plays a role in the debate about the
origins of the Indo-Europeans. High frequencies of haplogroup R1a are found amongst
West Bengal Brahmins (72%), and
Uttar Pradesh Brahmins, (67%), the
Ishkashimi (68%), the
Tajik population of
Panjikent (64%), the
Kyrgyz population of Central
Kyrgyzstan (63.5%),
Sorbs (63.39%),
Bihar Brahmins (60.53%),
Shors (58.8%), Poles (56.4%),
Teleuts (55.3%), Ukrainians (50%) and Russians (50%) (, , , and ).
R1b (R-M343) Haplogroup
R1b probably originated in
Eurasia prior to or during the last glaciation. It is the most common haplogroup in
Western Europe and
Bashkortostan . It may have survived the
last glacial maximum, in
refugia near the southern
Ural Mountains and
Aegean Sea.. It is also present at lower frequencies throughout Eastern Europe, with higher diversity than in western Europe, suggesting an ancient migration of haplogroup R1b from the east. Haplogroup R1b is also found at various frequencies in many different populations near the
Ural Mountains and
Central Asia, its likely region of origin. There may be a correlation between this haplogroup and the spread of
Centum branch
Indo-European languages in southern and western Europe. For instance, the modern incidence of R1b reaches between 60% and 90% of the male population in most parts of
Spain,
Portugal,
France,
Britain and
Ireland. The clade is also found at frequencies of up to 90% in the
Chad Basin, and is also present in
North Africa, where its frequency surpasses 10% in some parts of
Algeria. Although it is rare in
South Asia, some populations show relatively high percentages for R1b. These include
Lambadi showing 37% ().
Hazara 32% , and
Agharia (in
East India) at 30% . Besides these, R1b has appeared in
Balochi (8%),
Bengalis (6.5%), Chenchu (2%),
Makrani (5%),
Newars (10.6%), Pallan (3.5%) and
Punjabis (7.6%) (, , and ). In Southeast Asia, it is present in the Philippines due to Spanish and American colonization where different studies vary as to its frequency; from 3.6% of the male population, in a year 2001 study conducted by
Stanford University Asia-Pacific Research Center had European Y-DNA R1b to 13% in a Public Y-DNA Library.
R-M343 (previously called
Hg1 and
Eu18) is the most frequent Y-chromosome haplogroup in
Europe. It is an offshoot of R-M173, characterised by the
M343 marker. An overwhelming majority of members of R-M343 are classified as
R-P25 (defined by the P25 marker), the remainder as
R-M343*. Its frequency is highest in
Western Europe (and due to modern European immigration, in parts of the
Americas). The majority of R-M343-carriers of European descent belong to the
R-M269 (R1b1a2) descendant line. ==See also==