In Hindu society, the term gotra means is same of what modern day Ancestry is. t comes from Sages whose name Gotra comes from .
Gotra means cowshed (Go=Cow, tra=shed) in Sanskrit. Paini defines
gotra for grammatical purposes as apatyam pautraprabhrti gotram (IV. 1.
162), which means the word gotra denotes the progeny (of a sage)
beginning with the son’s son. The system does not mean coming from Brahman(not cast basis), but all who were educated were called Brahman, means know er.
Hindu Brahmins identify their male lineage by considering themselves
to be the descendants of the 8 great Rishis i.e Saptarishis (The Seven
Sacred Saints) + Bharadwaja Rishi. So the list of root Gotras is
as follows :
. Angirasa
. Atri
. Gautam
. Kashyapa
. Bhrigu
. Vasistha
. Kutsa
. Bharadwaja
The offspring (apatya) of these eight are gotras and others than
these are called gotravayava. These eight sages are called
gotrakarins from whom all the 49 gotras
have evolved.
For instance, from Atri sprang the Atreya and Gavisthiras gotras.In
almost all Hindu families, marriage within the same gotra is prohibited,
since people with same gotra are considered to be siblings.
It connects to the root Seer. Gotra does not have to pass from father
to children ,as in Malayalis and Tulu’s its passed on from mother
to children.
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. Now, why only male
carries fixed lastname and gotra and why female can change her last
name, gotra after marriage?
Genes and Chromosomes Among Humans
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 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).
But Mitochondrial gene in offspring comes only from mother so you can trace all son and daughter to mother by Mitochondrial gene.
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.
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.
Y 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.
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.
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.
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.
Even modern scientists have concluded that children born to parents
having blood relation (like cousins) can have birth defects. For
example, there is a recessive dangerous gene in one person.
Mathomathis