The inhabitants of the Lakshadweep Islands in the Arabian Sea share a genetic link with South Asians, especially mainland Indians, a landmark study by the Hyderabad-based CSIR-CCMB revealed.

The finding assumes significance as  Andaman & Nicobar Islanders share an ancestry with the migrants of Africa thousands of years ago, established by previous global genetic studies, including those by the Centre for Cellular & Molecular Biology (CCMB).

K Thangaraj, senior author of the study published in Scientific Reports on Monday said, “Our first genetic study suggests majority of human ancestry in Lakshadweep is largely derived from South-Asia with minor influences from East and West Eurasia.” He said there was no evidence of early human migration through the Lakshadweep islands.

Genetic signatures

“The Lakshadweep islands are located between Africa and south-western part of India. Through our earlier studies we know that early human migration from Africa to Andaman and Australia happened through western coast of India. So, we presumed that the Lakshadweep islands might have played a major role in early human migration and expected the presence of genetic signatures of ancient people, such as Andamanese and Australian aboriginals”, he said.

The islands were known to sailors since ancient times. Historical documents say that the spread of Buddhism to the islands happened during 3rd century BC, Islam in 661 AD by Arabians, Cholas in 11th century, Portuguese in 16th century, Ali Rajahs in 17th, Tipu Sultan in 18th and finally it was under British Raj in 19th century.

Historic interactions

“We have analysed DNA samples of 557 individuals from eight major islands for mitochondrial DNA and 166 individuals for Y chromosome markers. We analysed a strong founder effect for both paternal and maternal lineages — a sign that the island population had limited genetic mixing”, said M S Mustak, Associate Professor of the Department of Applied Zoology, Mangalore University and co-author.

The study covered eight major islands — Agatti, Andorth, Bitra, Chetlat, Kadmat, Kalpeni, Kiltan and Minicoy, and demonstrated a close genetic link of Lakshadweep islanders with Maldives, Sri Lanka and India. “Even after regular historic interactions with people from different regions of the world, it is extremely interesting that we could see only limited number of founders” said Gyaneshwer Chaubey of Banaras Hindu University.

Rakesh K Mishra, Director, CCMB, said the findings would help them analyse health profiles of the migrants in near future.

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