The Science behind GOTRA (Genetics), is nothing but what is today popularly known as GENE ~ MAPPING.
Infact, this is an amazing and ancient genetic science that we follow. Let's see the SCIENCE of GENETICS behind our great GOTRA systems.
The word GOTRA is formed from two Sanskrit words, GAU (meaning, Cow) and TRAHI (meaning, Shed).
GOTRA means Cow-shed.
GOTRA is like a cowshed protecting a particular male lineage. We identify our male lineage / Gotra by considering to be descendants of the 8 great Rishi (Sapta Rishi + Bharadwaj Rishi). All the other Gotra evolved from these only.
Biologically, the human body has 23 pairs of Chromosomes (one from father and one from mother). On these 23 pairs, there is one pair called Sex Chromosomes, which decides the Gender of person.
During conception, if the resultant cell is XX chromosome, then the child will be a Girl. If it is XY, then it will be a Boy.
In XY - X is from Mother and Y is from Father.
In this, Y is unique and it doesn't mix. So in XY, Y will supress the X and son will get Y chromosomes. Y is the only chromosome which gets passed down only between male lineage. (Father to Son and to Grandson).
Women never get the Y chromosome. Hence, the Y chromosome plays a crucial role in genetics, in identifying the genealogy. Since women never get Y chromosome, the Gotra of the woman is said to be of her husband, and therefore changes after she is married.
They are 8 different Y chromosomes from 8 Rishis. If we are from Same Gotra, then it means we are from the same root ancestor.
Marriages between same Gotra will increase the risk of causing genetic disorders as same Gotra Y chromosomes cannot have crossover, and it will activate the defective cells.
If this continues, it will reduce the size and strength of Y chromosome which is crucial for the creation of male.
If no Y chromosome is present in this world, then it will cause males to become extinct.
The GOTRA system is thus an ancient method devised by our great Maharishis to avoid genetic disorders and attempt to protect the Y chromosome.
Source : WhatApp, Author: Unknown.