Science Of Genetics Behind The Hindu Gotra System

[Audichya Brahmin all]

Science Of Genetics Behind The Hindu Gotra System – The Y Chromosome
And The Male Lineage
The Hindu Gotra System – Male Lineage Identification

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.

The Gotra system is practiced amongst most Hindus. See here for a List
of Hindu Gotras practiced by different sections of the Hindu Society

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).

Note that the English word Cow is a derived word of the Sanskrit word
Gau with the same meaning Gau.

So Gotra means Cowshed, where in the context is that Gotra is like the
Cowshed protecting a particular male lineage. Cows are extremely
important sacred animals to Hindus and there were a large number of
best breeds of Cows that ancient Hindus reared and worshipped, and
hence the name Gotra referring to the system of maintaining individual
male lineages seems more appropriate.

Importance of Son in the Gotra System

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.

So the rule of the Gotra system is that the Gotra of men remains the
same, while the Gotra of the woman becomes the Gotra of their husband
after marriage. Now suppose a person has only daughters and no sons.
In that case his Gotra will end with him in that lineage because his
daughters will belong to the Gotras of their husbands after their
marriage!

This was probably the reason why in the ancient vedic or hindu
societies it was preferred to have atleast one Son along with any
number of daughters, so that the Gotra of the father could continue.

But isn’t this crap? Why should only Sons carry the Gotra of their
father, why can’t daughters? How does the Gotra of a daughter change
just because she marries a person belonging to a different Gotra? 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 by chance while studying
a puzzle in modern Genetics for which the biologists are trying to
find an answer!

But before that..

A Girl and a Boy belonging to the same Gotra cannot marry!

This is the most important and the only rule in the Gotra system is 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. The reason given was
since they belonged to the same ancestor, it will be like a brother
marrying a sister which is known to cause genetic disorders in their
offspring.

As I can see now, probably the prevention of marriages within the same
Gotra was the only reason for the Gotra system to be created.

But again I used to think, what a crap, how can a boy and a girl
belonging to two different families who haven’t met for centuries be
considered as siblings?

Only until I was able to correlate a puzzle in modern Genetics to the
Gotra system.

And now to the Science behind the Gotra System, but before that let us
just check out one more additional rule related to marriages in the
Gotra System.

Pravaras and the Gotras

Pravara is a list of most excellent Rishis in a Gotra lineage. As we
saw earlier, 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.

This is because, the essence of the Gotra system is finally to prevent
marriages within the same Gotra. Now consider two derived Gotras which
came from the same Gotra, then it might happen that over time people
might forget that both these Gotras came from the same root Gotra, and
may allow marriages within these Gotras since their names are
different! To prevent this, the derived Gotras maintained a list of
Pravaras (which were the prominent junctions where the derived Gotras
got created), and the additional rule in the Gotra system is that,
even if the Bride and Bridegroom belong to different Gotras, they
still cannot get married even if just one of their Gotra Pravara
matches.

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



Derived Classes

Consider a Class B which is derived from Class A, and another Class C
which is also derived from Class B. Now Consider another Class D which
is derived from both Class B and Class C (multiple inheritance like in
C++). If we look at the immediate ancestry of Class D, then it appears
that Class B and Class C are the parents of Class D. But if you look
at the ancestors of Class B and Class C, then they are the Children of
Class A. Now if we replace the classes A, B and C with Gotras, then we
can see that even if two Gotras B and C are different Gotras, if they
share the same parent Gotra A (enlisted in the form of Pravaras), then
they will become siblings, and hence the marriage between two
different Gotras sharing the same Pravara is not allowed.

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)?

Now to the Science behind the Gotra System, but before that let us
refresh a bit of our knowledge about Genetics.

Chromosomes and Genes

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. X chromosome decides the female
attributes of a person and Y Chromosome decides the male attributes of
a person.

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 and the X Chromosome
from his mother. On the other hand daughters always get their X
Chromosomes, one each from both father and mother.

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

A mother will pass either her mother’s X Chromosome to her Children or
her father’s X Chromosome to her children or a combination of both
because of both her X Chromosomes getting mixed (called as Crossover).
On the other hand, a Son always gets his father’s Y Chromosome and
that too almost intact without any changes because there is no
corresponding another Y chromosome in his cells to do any mixing as
his combination is XY, while that of females is XX which hence allows
for mixing as both are X Chromosomes.

Y Chromosome and the Vedic Gotra System

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! And if a person belongs to
a Gotra (say Bharadwaja) with Pravaras (Angirasa, Bhaarhaspatya,
Bharadwaja), then it means that the person’s Y Chromosome came all the
way down from Angirasa to Bhaarhaspatya to Bharadwaja to the person.

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 after
marriage. Pretty neat isn’t it?

All iz well so far, 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, and hence created the Gotra system to
identify their male lineages. Lord Buddha for instance belonged to
Gautama Gotra which means that Buddha was a direct descendant of Rishi
Gautama.

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 Weakness of 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.

And the reason for all this is that unlike other Chromosomes, there is
no way for Y Chromosome to repair itself by doing cross over with its
Chromosomal pair. All other Chromosomes come in similar pairs and when
there the DNA of one Chromosome gets damaged the cell can repair it by
copying over the DNA from the other Chromosome in that pair as both
the Chromosomes in all other pairs are almost identical in nature.
This copying (or crossing over as it is called) also allows different
combinations of mix and matches to happen between the genes of mother
and father and allows the best of the matches to survive and hence
make the Chromosomes stronger as they evolve in successive
generations. Even X Chromosomes in female undergo this mix and match
since there are two X Chromosomes in women.

However Y Chromosomes do not have any corresponding equivalent
Chromosome in its pair. It can exist only in a XY Combination and X
cannot mix and match with Y except for a small 5% of X which matches
with Y, while the remaining 95% of Y Chromosome which is crucial in
the development of a male have absolutely no match at all!. It is this
95% of the Y Chromosome which is completely responsible in humans for
creating a male or a man.

But at the same time, Y Chromosome has to depend on itself to repair
any of its injuries and for that it has created duplicate copies of
its genes within itself. However this does not stop DNA damages in Y
Chromosome which escape its local repair process from being propagated
into the offspring males. This causes Y Chromosomes to accumulate more
and more defects over a prolonged period of evolution and scientists
believe that this is what is causing the Y Chromosome to keep losing
its weight continuously.

As discussed earlier other Chromosomes do not face this issue because
they have corresponding pairs from both the parents and the DNA damage
could be easily corrected most of the time by the mix and match
process that takes place between the two Chromosomes in a pair. This
Chromosomal crossover process eliminates damaged genes and is one of
the key processes in evolution of life.

So to summarize, Y Chromosome which is crucial for the creation and
evolution of males has a fundamental weakness which is denying it
participation in the normal process of evolution via Chromosomal mix
and match to create better versions in every successive generation,
and this weakness MAY lead to the extinction of Y Chromosome
altogether over the next few million years, and if that happens
scientists are not sure whether that would cause males to become
extinct or not. And that is because Scientists are not sure whether
any other Chromosome in the 23 pairs will be able to take over the
role of the Y Chromosome or not. Is there a 2012 like doomsday
calendar for Y Chromosome sometime in the future?

On the other hand, it is not necessary that humanity will not be able
to survive if males become extinct. Note that females do not need the
Y Chromosome, and since all females have X Chromosomes, it would be
still possible to create a mechanism where X Chromosomes from
different females are used to create offspring, say like injecting the
nuclei from the egg of one female into the egg of another female to
fertilize it and that would grow into a girl child. So yes, that would
be a humanity where only females exist.

Now I 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 – An attempt to protect the Y Chromosome from becoming
extinct ?

So here is my conclusion about the creation of the Gotra system by the
ancient learned Vedic Rishis. 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 or even probably completely stop any
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 (which self heals by having duplicate copies of
its genes) 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. What
this means is that say a person is carrying a dangerous abnormality
causing gene in one of his chromosome, but whose effect has been
hidden in that person (or is not being expressed) because the
corresponding gene in the pairing Chromosome is stronger and hence is
preventing this abnormality causing gene from activating.

Now there are fair chances that his offsprings will be carriers of
these genes throughout successive generations. As long as they keep
marrying outside his genetic imprint, there is a fair chance that the
defective gene will remain inactive since others outside this person’s
lineage most probably do not have that defective gene. Now if after
5-10 generations down the line say one of his descendants marries some
other descendant who may be really far away cousins. But then there is
a possibility that both of them are still carrying the defective gene,
and in that case their children will definitely have the defective
gene express itself and cause the genetic abnormality in them as both
the Chromosomes in the pair have the defective genes. Hence, the
marriages between cousins always have a chance of causing an otherwise
recessive, defective genes to express themselves resulting in children
with genetic abnormalities.

So if the Vedic Rishis had allowed marriages within the same Gotras,
then there were chances that the resulting male can be a victim of
such defective gene expression, and any such gene expressions which
took place in the 5% exposed area of the Y Chromosome would be fatal
for the continuity of that Y Chromosome. Even after hundreds of
generations there would still be chances of any defective genes being
propagated within these successive generations, and marriage within
the same Gotra would provide a golden opportunity for these genes to
express themselves, there by causing the genetic abnormality in the
offspring.

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 from
the human DNA.

Gotra System – A window of opportunity to study the Genetics of
ancient Vedic Rishis

To add a final note, the veracity of the Gotra system can be checked
by comparing the Y Chromosomes of males from different families of the
same Gotra who are religiously following the Gotra system even today.
That would not only prove the maintenance of male lineage throughout
generations for thousands of years, but would also provide us with an
opportunity to extract the Y Chromosomes of the ancient Vedic seers
and study them.

NOTE: Section below added on April 28 2011 in response to this and
this reader’s queries.

Why only the selected list of Rishis as root Gotras? Why not somebody
else?

When we look at the list of the Gotrakarni Rishis (ie the root
Gotras), you may note that almost all of these Rishis are also
Prajapatis – Prajapatis are those who were the immediate descendants
of Brahma (the Creator God) – who then went on to create their own
progeny or lineage.

So having the Gotra system start from the very beginning of human
lineage looks more apt and logical as this is where the chromosomes
and genes are still pure and free of any possible genetic defects.
Hence the Prajapatis were selected as the root of the Gotra System.

Note that genetic defects or disorders or bad genes get eventually
picked up over time during evolution due to genetic mutations.

Would love to know your thoughts on this

NOTE: Section below added on April 30 2011 in response to a reader’s
comment.

Is It adequate for a marriage if just the Gotra and Pravaras do not
match?

No. Please note that the intention of the Gotra system is to avoid
marriage within the same family and lineage as mentioned above, and
hence it also states that marriages are not recommended with the
maternal cousins even if the Gotras are different in this case.

To quote a rule of the Gotra System (Manusmriti 3/5)

AsapiMDAchayA mAtur sagOtrAchayA pituH |

sA praShasthA dvijAtInAM dArakarmaNi maithune ||

which means

When the man and woman do not belong to six generations from the
maternal side

and also do not come from the father’s lineage, marriage between the
two is good.

In other words, the Gotra System also does not recommend marriage with
maternal cousins either, even if the Gotras are different in this
case. This again is scientifically correct because cousin marriages
with maternal cousins (like the marriage of a Son with Mother’s
Sister’s Daughter) are also known to result in genetic disorders in
the offspring.

NOTE: Section below added on May 4 2011 to prevent the misuse of this
article by using this as a reference to prevent same Gotra marriages.

Should Gotra System be used to decide marriages?

Please note that of all the scientific reasonings mentioned in the
article about the Gotra System, the ONLY PROVED science is that the

Gotra System maintains a Genetic Male Lineage via Y Chromosome.

Cousin marriages within the immediate family relations are known to
cause Genetic Disorders

Now considering the fact that we are thousands of years away from when
this Gotra system originated, and the Indian demographics have
undergone substantial changes during this period – Whether we need to
retain the Gotra rules in deciding marriage alliance and whether same
Gotra Boy and Girl (when they come from distant families) still share
the same genes like between immediate cousins – should be left to
Science.

The Gotra System might have had its benefits in its initial days as it
prevented marriages between closely related cousins then. But how
appropriate would it be follow this system thousands of years later
today in deciding matrimonial alliances? If Genetic studies based on
analysis of Same Gotra families have not found any problem with same
Gotra marriages scientifically, then there is no point in continuing
with the Gotra system to decide matrimonial alliances.

Marriage is finally more of a bond between two souls rather than two
bodies, so its nobody’s business to interfere in a marriage where the
boy and girl are above minimal legal age required for marriage and are
marrying with mutual consent.