Here is something informative from an other site and about a different subject matter. It should go to the general section of this website.
It is the blessing and mercy of Akal Purakh and Guru Nanak Dev Sahib Ji that we were given a new and fresh life, after centuries of old dead theories, philosphies and human linkages."""""""""""""""""""""""""Many historical happenings such as invasions, wars, civil unrests migrations and religious conversions have shaped the heritage of India. This was stated by Dr. B.S.Ahloowalia, a Vienna, Austria based scientist while interacting with students and faculty members of the Plant Breeding and Genetics in a meeting organized by the PAU Science Club, today. Dr. Ahloowalia said that these events created a potpourri of cultures and genes. He, while tracing the historical events in India said that the invaders hailed from different regions of the world including central Asia, Afghanistan, Arabia, Iran, Greece, Britain, France, and Portugal to loot and plunder wealth but also left their genes behind among Indians irrespective of their caste or creed. The legacy of what the inherit from our parents are the genes and not blood, said he. He emphasized that all humans of today (Homo sapiens) descend from a group of African ancestors who, about 60000 years ago began a remarkable journey to populate the earth. The migration of Homo sapiens into India occurred about 40000 years ago, said Dr. Ahloowalia.
Discussing gene invasion, Dr. Ahloowalia said that the caste-based marriage system broke down under several situations e.g., when there is an invasion from outside leading to wars, in which the males were selectively killed and the native females were forcefully married; or when there was an internal socio-economic unrest alongwith killing/displacement of males; or when there was large-scale selective migration of males either on a voluntary basis or through enslavement. Once the genes invade, they do not die, observed Dr. Ahloowalia. He said that adivasis might be genetically pure and that Punjabis are tall-statured because of selection pressure for survival. Genes once introduced in a population, caste or a social group continue to spread through shuffling and re-shuffling, and become part of the gene pool of the population, said he. Only such populations in which strict endogamy is the rule may carry original genes in pure form, however, such genetically pure populations do not exist in India, observed Dr. Ahloowalia adding that even the tribal populations having strict endogamy are a mixture of several ethnic groups. He said that future genetic research based on the modern molecular techniques shall reveal the specific gene blocks present in each caste, but shall also show the presence of genes that were introduced and spread into them through gene invasions. Dr. Ahloowalia said that research studies on Indian ethinic origins, similar to those undertaken in the 'The genographic project' should be an eye opener to the caste-ridden social structures, which are still trying to control and restrict flow of genes between different castes in India.""""""""""""""""""""
ਸਤਿਗੁਰਬਚਨਕਮਾਵਣੇਸਚਾਏਹੁਵੀਚਾਰੁ॥