Science behind Gotra (Genetics) :-
What is Gotra system ?
Why do we have this ? Why do we consider this to decide the marriages ?
Why should sons carry the gotra of the father, why not the daughter ?
How/why does gotra of a daughter change after she gets married ?
What is the logic ?
Infact, this is an amazing genetic science we follow.
Let's see the science of genetics behind gotra systems :-
The word GOTRA formed from two sanskrit words GAU (means cow) and TRAHI (means shed).
Gotra means cowshed.
Gotra is like cowshed protecting a particular male lineage. We identify our male lineage / gotra by considering to be descendants of the 8 great Rishis (Sapta rishi + Bharadwaj rishi ). All the other gotras had evolved from these only.
Biologically, human body has 23 pairs of chromosomes (one from the father and one from the mother). On these 23 pairs, there is one pair called sex chromosomes which decides the gender of the person.
During conception, if the resultant cell is XX chromosomes ,then the child will be girl, if it is XY chromosomes then it is boy.
In XY - 'X' is from the mother and 'Y' is from the 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 the Son and to the Grandson).
Women never gets Y. Hence, Y plays a crucial role in genetics in identifying the genealogy.
Since women never get Y, the Gotra of the woman is said to be of her husband.
They are 8 different Y chromosomes from the 8 Rishis. If we are from Same Gotra, then it means we are from same root of the 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.
So Gotra system is a method to avoid genetic disorders and attempt to protect Y chromosome.
*Amazing bio-science by our Maharishis.
*They had the "Gene Mapping" sorted out thousands of years ago.