Monday, September 28, 2009

Aryan-Dravidian divide a myth: Study


Aryan-Dravidian divide a myth: Study
TNN 25 September 2009

http://timesofindia .indiatimes. com/news/ india/Aryan- Dravidian- divide-a- myth-Study/ articleshow/ 5053274.cms

HYDERABAD: The great Indian divide along north-south lines now stands
blurred. A pathbreaking study by Harvard and indigenous researchers on
ancestral Indian populations says there is a genetic relationship
between all Indians and more importantly, the hitherto believed
``fact'' that Aryans and Dravidians signify the ancestry of north and
south Indians might after all, be a myth.

``This paper rewrites history... there is no north-south divide,''
Lalji Singh, former director of the Centre for Cellular and Molecular
Biology (CCMB) and a co-author of the study, said at a press
conference here on Thursday.

Senior CCMB scientist Kumarasamy Thangarajan said there was no truth
to the Aryan-Dravidian theory as they came hundreds or thousands of
years after the ancestral north and south Indians had settled in

The study analysed 500,000 genetic markers across the genomes of 132
individuals from 25 diverse groups from 13 states. All the individuals
were from six-language families and traditionally ``upper'' and
``lower'' castes and tribal groups. ``The genetics proves that castes
grew directly out of tribe-like organizations during the formation of
the Indian society,'' the study said. Thangarajan noted that it was
impossible to distinguish between castes and tribes since their
genetics proved they were not systematically different.

The study was conducted by CCMB scientists in collaboration with
researchers at Harvard Medical School,
Harvard School of Public Health and the Broad Institute of Harvard and
MIT. It reveals that the present-day Indian population is a mix of
ancient north and south bearing the genomic contributions from two
distinct ancestral populations - the Ancestral North Indian (ANI) and
the Ancestral South Indian (ASI).

``The initial settlement took place 65,000 years ago in the Andamans
and in ancient south India around the same time, which led to
population growth in this part,'' said Thangarajan. He added, ``At a
later stage, 40,000 years ago, the ancient north Indians emerged which
in turn led to rise in numbers here. But at some point of time, the
ancient north and the ancient south mixed, giving birth to a different
set of population. And that is the population which exists now and
there is a genetic relationship between the population within India.''

The study also helps understand why the incidence of genetic diseases
among Indians is different from the rest of the world. Singh said that
70% of Indians were burdened with genetic disorders and the study
could help answer why certain conditions restricted themselves to one
population. For instance, breast cancer among Parsi women, motor
neuron diseases among residents of Tirupati and Chittoor, or sickle
cell anaemia among certain tribes in central India and the North-East
can now be understood better, said researchers.

The researchers, who are now keen on exploring whether Eurasians
descended from ANI, find in their study that ANIs are related to
western Eurasians, while the ASIs do not share any similarity with any
other population across the world. However, researchers said there was
no scientific proof of whether Indians went to Europe first or the
other way round.

Migratory route of Africans

Between 135,000 and 75,000 years ago, the East-African droughts shrunk
the water volume of the lake Malawi by at least 95%, causing migration
out of Africa. Which route did they take? Researchers say their study
of the tribes of Andaman and Nicobar islands using complete
mitochondrial DNA sequences and its comparison those of world
populations has led to the theory of a ``southern coastal route'' of
migration from East Africa through India.

This finding is against the prevailing view of a northern route of
migration via Middle East, Europe, south-east Asia, Australia and then
to India.



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