New Delhi, Jan. 11: Two new genetic studies have disputed long-held beliefs that pastoral central Asian people brought agriculture to India and contributed heavily to the genetic make-up of modern Indian populations.
The central Asian people who migrated to India included the Aryans who began arriving around 3,500 years ago.
The studies by scientists in Calcutta with colleagues in other countries might force historians to revise current ideas about the impacts of migrations from central Asia beginning about 8,000 years ago on India.
A study by scientists at the Central Forensic Science Laboratory in Calcutta has revealed that most present-day Indians are the descendants of early humans who began to arrive in India about 60,000 years ago. It suggests that modern Indians do not owe much genetic makeup to central Asians who arrived much later.
The findings do lend support to the migration of people from central Asia into India.
“Although we did find genetic signatures from central Asian populations in Indian communities, there are not enough (signatures) to prove large-scale mixture with local populations,” research team leader Vijendra Kashyap told The Telegraph.
The scientists, who analysed the Y-chromosomes of 936 men from 77 castes and tribes across India, published their findings in the journal, Proceedings of the National Academy of Sciences, on Monday.
The conventional view has been that pastoral central Asians, also called Indo-Europeans, brought agriculture into India, although some researchers have challenged this in the past.
“The perennial concept of people, language and agriculture arriving in India together through the northwest corridor does not hold up to close scrutiny,” Kashyap and his colleagues at the University of Oxford and the Estonian Biocentre said in their research paper.
The analysis of certain sections of the human genome ' such as the Y-chromosome in men or the mitochondrial DNA in women ' can help scientists determine the “genetic distance” between races and piece together ancient human migratory patterns.
Recent studies by international research teams have shown that the earliest modern humans arrived in India from Africa, trudging along the Indian Ocean coast about 60,000 years ago on their way further into southeast Asia.
“Our findings suggest most modern Indians have genetic affinities to the early settlers and subsequent migrants and not to central Asians or Aryans, as they’re called,” a research scholar at the CFSL said.
The CFSL study also failed to find specific genetic signatures associated with the world’s earliest farmers in any of the 936 men in India. These signatures have been earlier found in central Asia, North Africa and Europe.
An independent genetic study by Partha Mazumder at the Indian Statistical Institute in Calcutta with colleagues at Stanford University and elsewhere has found that the majority of genetic signatures among men in India are older than 10,000 years.
The study of 1,100 men from 36 ethnic groups in India, 8 in Pakistan and 18 from the southeast Asian region has indicated that many of the genetic signatures have arisen in India and predate the arrival of the Indo-Europeans and their expansion in India.
“The genetic contribution from central Asia has not been as large as generally believed,” Mazumder said.
His study has also indicated that the genetic input of people who might have brought agriculture into India from West Asia has been limited.
The oldest known site of agricultural activity so far in the subcontinent is Mehrgarh in Pakistan where there is evidence of cultivation of barley and wheat in 7000 BC. But some scientists believe that agriculture emerged spontaneously in India and wasn’t brought here.
A few years ago, archaeologists had a few years ago unearthed the remains of an ancient settlement near Udaipur in Rajasthan that they say points to the independent evolution of cultivation in India.