Thread by @HinduMediaWiki

Science of Genetics behind the Hindu Gotra System :

The Gotra is a system which associates a person with his most ancient or root ancestor in an unbroken male lineage.

For instance if a person says that he belongs to the Bharadwaja Gotra then it means that he traces back his male ancestry to the ancient Rishi (Saint or Seer) Bharadwaja. So Gotra refers to the Root Person in a person’s male lineage.

Brahmins identify their male lineage by considering themselves to be the descendants of the 8 great Rishis ie Saptarshis (The Seven Sacred Saints) + Bharadwaja Rishi. So the list of root Brahmin Gotras is as follows

Angirasa
Atri
Gautam
Kashyapa
Bhrigu
Vasistha
Kutsa
Bharadwaja

These 8 Rishis are called Gotrakarin meaning roots of Gotras. All other Brahmin Gotras evolved from one of the above Gotras. What this means is that the descendants of these Rishis over time started their own Gotras.

The total number of established Gotras today is 49. However each of them finally trace back to one of the root Gotrakarin Rishi.

The word Gotra is formed from the two Sanskrit words Gau (meaning Cow) and Trahi (meaning Shed).

This Gotra system helps one identify his male lineage and is passed down automatically from Father to Son. But the Gotra system does not get automatically passed down from Father to Daughter. Suppose a person with Gotra Angirasa has a Son.

Now suppose the Son gets married to a girl whose father belongs to Gotra Kashyapa. The Gotra of the girl automatically is said to become Angirasa after her marriage even though her father belonged to Gotra Kashyapa.

What is the necessity of maintaining only the man’s ancestry, why not maintain that of women too? This was the question that was puzzling me about this Gotra system till recently, until I found out the scientific reasoning behind the Gotra system in a puzzle in modern Genetics

This is the most important and the only rule in the Gotra system if I may say so. Yes, a Bride and a Bridegroom belonging to the same Gotra are considered to be siblings and hence it is prohibited for them to marry even if they belong to distant families.

Pravara is a list of most excellent Rishis in a Gotra lineage.

Some of the descendants of the most ancient Gotras started their own Gotras, however they maintained a list of Pravaras while doing so and attached the list of their most excellent Ancestors with this derived Gotras.

For instance the Vatsa Gotra has Bhargava, Chyavana, Jamadagnya , Apnavana as their Pravaras. What this means is that Vatsa Gotra has in its lineage all these Gotras and traces back its root to Bhrigu Rishi in the list of Gotrakarins.

The idea behind this Pravara system is probably to ensure that the derived Gotras still maintain track of their root Gotras, and this in turn is used to ensure that Bride and Bridegroom from no two derived Gotras coming from the same root Gotra marry each other.

Every Gotra which is a derived Gotra maintains a list of Pravaras attached to it.

It makes sense as this prevents marriages between derived Gotras which belong to the same root Gotra. This reminds of a similar logic in the modern Object Oriented Programming in Software Systems.

But again the question remained – what is the basis to prevent marriages within the same Gotras even after thousands of years later the roots separated?

How can hundreds of generations later they can still be considered to be the children of same parents just because they belong to same Gotra (male lineage) or to different Gotras sharing the same Pravara (again the male lineage)?

Humans have 23 pairs of Chromosomes and in each pair one Chromosome comes from the father and the other comes from the mother. So in all we have 46 Chromosomes in every cell, of which 23 come from the mother and 23 from the father.

Of these 23 pairs, there is one pair called the Sex Chromosomes which decide the gender of the person. During conception, if the resultant cell has XX sex chromosomes then the child will be a girl and if it is XY then the child will be a boy.

When the initial embryonic cell has XY chromosome, the female attributes get suppressed by the genes in the Y Chromosome and the embryo develops into a male child. Since only men have Y Chromosomes, son always gets his Y Chromosome from his father & the X Chrom, from his mother.

So the Y Chromosome is always preserved throughout a male lineage (Son – Grandson etc) because a Son always gets it from his father, while the X Chromosome is not preserved in the female lineage (Daughter, Grand Daughter etc) because it comes from both father and mother.

By now you might have got a clue about the relation between Y Chromosome and the Hindu Vedic Gotra System :)

Y Chromosome is the only Chromosome which gets passed down only between the men in a lineage. Women never get this Y Chromosome in their body.

And hence Y Chromosome plays a crucial role in modern genetics in identifying the Genealogy ie male ancestry of a person.

And the Gotra system was designed to track down the root Y Chromosome of a person quite easily.

If a person belongs to Angirasa Gotra then it means that his Y Chromosome came all the way down over thousands of years of timespan from the Rishi Angirasa!

This also makes it clear why females are said to belong to the Gotra of their husbands after marriage.

That is because women do not carry Y Chromosome, and their Sons will carry the Y Chromosome of the Father and hence the Gotra of a woman is said to be that of her husband!!

We now know the science behind the Gotra System. The ancient vedic Rishis hence very well knew the existence of the Y Chromosome and the paternal genetic material that was passed almost intact from father to Son, & hence created the Gotra system to identify their male lineages.

But then what is the reason to prevent marriages between individuals belonging to the same Gotra? Before we get into that, let us understand a bit more about the Y Chromosome.

The Y Chromosome is the only Chromosome which does not have a similar pair in the human body.

The pair of the Y Chromosome in humans is X Chromosome which is significantly different from Y Chromosome. Even the size of the Y Chromosome is just about one third the size of the X Chromosome.

In other words throughout evolution the size of the Y Chromosome has been decreasing and it has lost most of its genes and has been reduced to its current size. Scientists are debating whether Y Chromosome will be able to survive for more than a few million years into the future

...or whether it will gradually vanish, and if it does so whether it will cause males to become extinct!

Obviously because Y Chromosome is the one which makes a person male or a man.

And if it becomes extinct, Biologists are not sure whether any other Chromosome in our body will be able to completely take over its functionality or not.

On the other hand, it is not necessary that humanity will not be able to survive if males become extinct.

Now you will understand why Hinduism and its Vedic core regard Mother Goddess or female divinity to be more powerful than all male divinity put together :)

Gotra System Is An attempt to protect the Y Chromosome from becoming extinct.

The Vedic Rishis had observed the degeneration of the Y Chromosome and they wanted to maintain as many individual healthy unique Y Chromosome lineages as possible.

That would give a fair chance for males to continue to exist because Y Chromosomes get passed on over generations with almost negligible change in their genetic combinations, as they do not take part in mix and match with other Chromosome.

So if the Rishis could devise a mechanism where in a given Y Chromosome had very little chance of adding more genetic defects in it, then they could probably succeed in either slowing down further degeneration of the Y Chromosome.

And the only way to stop that was to ensure that the 5% of the Y Chromosome which can be mixed and crossed over with its X counterpart be protected so that the remaining 95% which does not take part in the mix and match process stays healthy.

Now we know even in modern Genetics that marriages between cousins will increase the risk of causing genetic disorders. That is because, say suppose there is a recessive dangerous gene in one person...

Now there are fair chances that his offsprings will be carriers of these genes throughout successive generations.

So, the marriages between cousins always have a chance of causing an otherwise recessive, defective genes to express themselves resulting in genetic abnormalities.

And hence the ancient Vedic Rishis created the Gotra system where they barred marriage between a boy and a girl belonging to the same Gotra no matter how deep the lineage tree was, in a bid to prevent inbreeding and completely eliminate all recessive defective genes in our DNA.

The above thread is based on Gurudev's blog at hitxp.com

Please read this article for more information in depth.

hitxp.com/articles/veda/…