Demographic information and frequency distribution of Y chromosome haplogroups

India is a country with enormous social and cultural diversity due to its
positioning on the crossroads of many historic and pre-historic human
migrations. The hierarchical caste system in the Hindu society dominates the
social structure of the Indian populations. The origin of the caste system in
India is a matter of debate with many linguists and anthropologists suggesting
that it began with the arrival of Indo-European speakers from Central Asia about
3500 years ago. Previous genetic studies based on Indian populations failed to
achieve a consensus in this regard. The analysis of the Y-chromosome and
mitochondrial DNA of three tribal populations of southern India, compared the
results with available data from the Indian subcontinent and tried to
reconstruct the evolutionary history of Indian caste and tribal populations. 
This article will give you the exact picture of historic and pre-historic human
migrations and its distribution at present in India.

Demographic information and frequency distribution of Y chromosome haplogroups
in Indian populations

Haplogroups (Y-DNA) –

In human genetics, a Human Y-chromosome DNA haplogroup is a haplogroup defined by differences in the non-recombining portions of DNA from the Y chromosome (called Y-DNA). The Y chromosome consortium has established a system of defining
Y-DNA haplogroups by letters A through to T, with further subdivisions using
numbers and lower case letters. Y-chromosomal Adam is the name given by
researchers to a theoretical male who is the most recent common patrilineal
(male-lineage) ancestor of all living humans. Estimations of the date of this
common ancestor have varied significantly in different studies.
R2, R1a1 – Mostly Indo-European found in Central, East and West India like UP,
BHI, ORI, WB and MAH states. Mainly found in upper caste.

L, L1 – Mostly Dravidian in South India like AP, KAR and TN states.

O2a, P – Mostly Austro-Asiatic in East India like JHA, ORI and WB
O2a, O3e – Mostly Tibeto-Burman in Northeast India like SIK, MZ, Meghalaya and
ARU states. Mainly found in lower caste and tribe.

Indian Tribes -      High – O, H     Average – P, J, L      Low – R
Indian Lower Castes –     High – P, L, H     Average – O     Low – J, R
Indian Upper Castes -     High – R, J, L     Average -      Low – H, O, P
L – Haplogroup L is associated with South Asia, L is found mostly in the Indian subcontinent and appeared approximately 30,000 years ago and also found in
Pakistan and ShriLanka. Haplogroup L is currently present in the Indian
population at an overall frequency of ca. 7-15% and rare in tribal groups about
L1 – L1 is typical of the Dravidian people of South India

P – It is believed to have arisen north of the Hindu Kush, in Siberia,
Kazakhstan, or Uzbekistan, approximately 35,000 to 40,000 years ago. This
generally found in Muslims of Manipur (30%) and the Madia Gond(25%)
O – First appeared according to different theories, either in Southeast Asia, or
East Asia approximately 35,000 years ago.

O2a – Haplogroup O2a is distributed widely in East and Southeast Asia, from
southern India to the Altai Mountains and Central Asia in the west, and from
Indonesia to northern China and Japan in the east, islands of Sumatra, Java,
Bali, Malaysia, Singapore, Thailand, Cambodia, Taiwanese, Philippines and
Nicobar Islands.

O3e – Same as O2a. Haplogroup O3e is typically found in East/Southeast Asia.
Found in India due to large-scale immigration of Tibeto-Burman speakers.
H – It is a branch of Haplogroup F, and is believed to have arisen in India
between 20,000 and 30,000 years ago. Having tribal populations of 25-35% in
India. Generally found among populations of India, Sri Lanka, Nepal, and
J – Haplogroup J is believed to have arisen roughly 30,000 years ago in
Southwest Asia (Arabia Felix). In Northern India, 28.7% of the Shia Muslim
population belongs to haplogroup J.

T – Possible place of origin is Middle East and appeared approximately 30,000
years ago. Among populations of India, haplogroup T has been found to be
particularly common among the Bauri, a Dalit caste of fishermen in East India,
and the Kurru (also known as Yerukula), a Dravidian tribe of South India.

R - 
Subclades -        F  —-> K —–> P —-> R

R – This haplogroup is believed to have arisen around 20,000-34,000 years ago,
somewhere in Central Asia or South Asia, where its ancestor Haplogroup P.
R1a – the highest levels of R1a (>50%) are found across the Eurasian Steppe:
West Bengal Brahmins (72%), and Uttar Pradesh Brahmins, (67%).

R1a1 – R1a1 origin is 21,000 years ago in southern Russia. R1a1 found in Western
India (Gujarat) through Pakistan and Kashmir, then via Central Asia and Russia,
R2 – R2 origin is in southern Central Asia between the Caspian and the Hindu
R2a – R2a made its first entry into the Indian sub-continent around 25,000 years
ago. The routes taken are not clear, although the Indus and Ganges rivers are
possible theories put forward. There could, of course, have been multiple
immigrations of this haplogroup into the Indian sub-continent, both in the
Paleolithic and the Neolithic.

Haplogroup R2a is present both in Dravidian and other Indian populations,
meaning that R2a has a pan-Indian presence, and not restricted to any linguistic

Haplogroup R2a has a more significant presence in middle and upper castes. The
frequencies of R2a seem to mirror the frequencies of R1a (i.e. both lineages are
strong and weak in the same social and linguistic subgroups). This may indicate
that both R1a and R2a moved into India at roughly the same time or cohabited,
although more research is needed.

R1a1 and R2a haplogroups indicate demographic complexity that is inconsistent
with a recent single history and is not inconsistent with a more proximal
Central Asian input of the R2a haplogroup in the upper castes. R2a has a
particularly strong presence in the Indian states of West Bengal, Uttar Pradesh
and Gujarat, and in the area of Mumbai (Bombay).

The paper claims that there is no evidence that Central Asia was the source of
the R1a and R2a lineages in India. The theory that Central Asia could have been
the recipient of the two lineages from India should not be ruled out. In
addition, the data are not inconsistent with complex exchanges of this
haplogroup between Central Asia and the Indian sub-continent, with the latter
being both the source and the recipient at different times.

R2a within South Asia, very high frequencies shown by some social groups include
Karmali of West Bengal at (16/16) 100%, Jaunpur Kshatriya of Uttar Pradesh at
(41/47) 87% and Kamma Chaudhary of Andhra Pradesh at (11/15) 73%. Other South
Asian communities that have a reasonably high frequency include Sinhalese with
(15/39) 38%, people of West Bengal at 23%, Lodha, an Austro-Asiatic tribe in
East India with 43%, Pallans, a Dravidian community in South India with 14%,
Konkanastha or Chitpavan Brahmins of Western India with 26% and Punjabi Brahmins
of North India with 25%. The data reported by Sengupta (2006) show a prevalence
of 20% (10/51) of this haplogroup in the three Indo-European-speaking Brahmin
groups (Uttar Pradesh, West Bengal, Konkanasth). This lineage also forms 5% of
Punjabi males. North Indian Muslims have a frequency of 11%(Sunni) and 9%(Shia),
while Dawoodi Bohra Muslim in the western state of Gujarat have a frequency of
16% and Mappla Muslims of South India have a frequency of 5%.

The R2a haplogroup is also found in 14% of the Burusho people who speak the
language isolate called Burushaski.Some of the other studies like Bamshad et
al., 2001, Kivisild et al., 2003 found Haplogroup 1(the old representation for
non-R1a1 Haplogroup R subclades) at around 40% among Telugus of coastal Andhra
Pradesh. The identification of this Haplogroup with R2a is confirmed from
Sanghamitra Sahoo et al., 2006 study which observed R2a ranging from 35% to 55%
among non-Brahmin castes of this region.

With Regards

Sandip Patil 

Mumbai, 8149645674

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