Caste system in India is not archaic as per genetic study

# Science in the news

 Scientists from Harvard Medical School and the 
CSIR-Centre for Cellular and Molecular Biology in Hyderabad, India, 

provide evidence that modern-day India is 
the result of recent population mixture among divergent demographic groups.

The American Journal of Human Genetics, Volume 93, Issue 3, 422-438, 08 August 2013

Genetic Evidence for Recent Population Mixture in India. (https://www.cell.com/AJHG/abstract/S0002-9297%2813%2900324-8)

Between 4,000 and 2,000 years ago, intermarriage in India was rampant. Figure by Thangaraj Kumarasamycourtesy share: http://hms.harvard.edu/news/genetics-proves-indian-population-mixture-8-8-13

pic courtesy;http://www.sciencedirect.com/

science/article/pii/S0002929713003248

pic courtesy;http://www.sciencedirect.com/

science/article/pii/S0002929713003248

1. Ancient India had no castes (system) structure in their social fabric. All communities used to have marital relation among them.

2. Caste structure came in existence around some 1900-4200 years ago due to diminishing trend in inter-community (caste) marriages. Gradually marriage in own caste were strictly followed and then society evolved to the present state of Indian caste system.

3. There is no difference in high or low caste or a Tribe. All Indians are the mixed progenies of North Indian ancestors and South Indian ancestors. This mixture resulted due to inter-community marriages and continued for thousands of years. This is still evident in certain Tribes living secluded from urban society of the day.

4. Marriages in the same community resulted their susceptibility to the genetic diseases, as various 'recessive' genes responsible for diseases, have become 'dominant'.

Abstract: Most Indian groups descend from a mixture of two genetically divergent populations: Ancestral North Indians (ANI) related to Central Asians, Middle Easterners, Caucasians, and Europeans; and Ancestral South Indians (ASI) not closely related to groups outside the subcontinent. The date of mixture is unknown but has implications for understanding Indian history. We report genome-wide data from 73 groups from the Indian subcontinent and analyze linkage disequilibrium to estimate ANI-ASI mixture dates ranging from about 1,900 to 4,200 years ago. In a subset of groups, 100% of the mixture is consistent with having occurred during this period. These results show that India experienced a demographic transformation several thousand years ago, from a region in which major population mixture was common to one in which mixture even between closely related groups became rare because of a shift to endogamy.      

#Resources thankfully consulted and cited for the above article from:
1. Science Reporter, CSIR, India, February 2014 issue, Gyanendra Mishra's article.

2. The American Journal of Human Genetics, Volume 93, Issue 3, 422-438, 08 August 2013

Genetic Evidence for Recent Population Mixture in India. 

(https://www.cell.com/AJHG/abstract/S0002-9297%2813%2900324-8)

Priya Moorjani, Kumarasamy Thangaraj, Nick Patterson, Mark Lipson, Po-Ru Loh, Peryasamy, Govindaraj, Bonnie Berger, David Reich, Lalji Singh

Department of Genetics, Harvard Medical School, Boston, MA 02115, USA

Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA

CSIR-Centre for Cellular and Molecular Biology, Hyderabad 500 007, India

Department of Mathematics and Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA 

#related blog post:
http://sciencedoing.blogspot.in/2014/06/relation-of-caste-religion-language.html