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Nature 463, 536-539 (28 January 2010)
Published on line 13 January 2010
Men more evolved?
Y chromosome study stirs debate Women may think of men as primitive,
but new research indicates that the Y chromosome - the thing that makes a man male -
is evolving far faster than the rest of the human genetic code.
A new study comparing the Y chromosomes from humans and chimpanzees, our nearest
living relatives, show that they are about 30 percent different. That is far greater than
the 2 percent difference between the rest of the human genetic code and that of the
chimp's, according to a study appearing on line, Wednesday in the journal Nature.
These changes occurred in the last 6 million years or so, relatively recently when it
comes to evolution.The Y chromosome appears to be the most rapidly evolving of
the human chromosomes,” said study co-author Dr. David Page, director of the
prestigious Whitehead Institute in Cambridge and a professor of biology at MIT.
It's an almost ongoing churning of gene reconstruction. It's like a house that's constantly
being rebuilt.
Before men get too impressed with themselves, lead author Jennifer Hughes offers
some words of caution: Just because the Y chromosome, which determines gender,
is evolving at a speedy rate it doesn't necessarily mean men themselves are more evolved.
Researchers took the most detailed examination of the Y chromosome, which females do not
have,
of both humans and chimps and found entire sections dramatically different.
There were even entire genes on the human Y chromosome that weren't on the chimp,
said Hughes, also of the Whitehead Institute.
The two-year research took twice as long as expected because of the evolutionary
changes found, Hughes said.
There is a bit of a proviso to the comparison to other chromosomes. While all human
and chimp chromosomes have been mapped, only two chimp chromosomes have been
examined in great detail: Y and chromosome 21. Yet, there's still enough known to make
the claim that the Y is the speediest evolver, Hughes and Page said.
Until recently the Y chromosome was considered the Rodney Dangerfield of genetics,
especially because it had fewer genes than other chromosomes. A few years ago some
researchers even suggested that the Y chromosome was shrinking so that in 50,000 years
it would just disappear and so would men.
The story is not as cut and dried as many would have liked to predict," Hughes said.
It's kind of fun to say that men are going to die out, but the science is proving - now that
we've got data - that that's not true at all.”
-AP
Published on line 13 January 2010
Men more evolved?
Y chromosome study stirs debate Women may think of men as primitive,
but new research indicates that the Y chromosome - the thing that makes a man male -
is evolving far faster than the rest of the human genetic code.
A new study comparing the Y chromosomes from humans and chimpanzees, our nearest
living relatives, show that they are about 30 percent different. That is far greater than
the 2 percent difference between the rest of the human genetic code and that of the
chimp's, according to a study appearing on line, Wednesday in the journal Nature.
These changes occurred in the last 6 million years or so, relatively recently when it
comes to evolution.The Y chromosome appears to be the most rapidly evolving of
the human chromosomes,” said study co-author Dr. David Page, director of the
prestigious Whitehead Institute in Cambridge and a professor of biology at MIT.
It's an almost ongoing churning of gene reconstruction. It's like a house that's constantly
being rebuilt.
Before men get too impressed with themselves, lead author Jennifer Hughes offers
some words of caution: Just because the Y chromosome, which determines gender,
is evolving at a speedy rate it doesn't necessarily mean men themselves are more evolved.
Researchers took the most detailed examination of the Y chromosome, which females do not
have,
of both humans and chimps and found entire sections dramatically different.
There were even entire genes on the human Y chromosome that weren't on the chimp,
said Hughes, also of the Whitehead Institute.
The two-year research took twice as long as expected because of the evolutionary
changes found, Hughes said.
There is a bit of a proviso to the comparison to other chromosomes. While all human
and chimp chromosomes have been mapped, only two chimp chromosomes have been
examined in great detail: Y and chromosome 21. Yet, there's still enough known to make
the claim that the Y is the speediest evolver, Hughes and Page said.
Until recently the Y chromosome was considered the Rodney Dangerfield of genetics,
especially because it had fewer genes than other chromosomes. A few years ago some
researchers even suggested that the Y chromosome was shrinking so that in 50,000 years
it would just disappear and so would men.
The story is not as cut and dried as many would have liked to predict," Hughes said.
It's kind of fun to say that men are going to die out, but the science is proving - now that
we've got data - that that's not true at all.”
-AP
From The Times January 14, 2010
Why the Y chromosome is a hotbed for evolution
Mark Henderson, Science Editor
The Y chromosome is often seen as the rotten corner of the human genome “ a place
of evolutionary decline that is slowly decaying and threatening the end of man. Reports
of its imminent demise, however, have been exaggerated.
Research has indicated that, far from stagnating, the male chromosome is a hotspot
of evolution that is changing more quickly than any other part of humanity's genetic code.
In most mammals the sex of offspring is determined by X and Y chromosomes.
Females have two XS, males have one X and one Y - with the Y making them male.
The Y was originally identical to the X, but over 300 million years it has shrunk, and is now
the smallest human chromosome.This is because it occurs on its own, and cannot swap
genes to maintain integrity. This decline has led scientists to suggest it would waste away
entirely in 125,000 years or so. This would mean the end of men, and probably of humanity.
But the first comparison of the human Y chromosome with its counterpart in chimpanzees
has revealed that they differ radically. The findings suggest that the Y chromosomes of
both are evolving rapidly and dynamically ' probably because of their critical roles in
reproduction
and have a vibrant future.
In the new research, which is published in the journal Nature, Dr David Page, of the
Massachusetts
Institute of Technology ' who first sequenced the Y chromosome in 2003 ' has now sequenced
the Y chromosome of the chimp, humanity's closest relative, and compared this with the human
version.
The scientists expected the two sequences to look very similar. However, while human and
chimp DNA
generally differ by less than 2 per cent, more than 30 per cent of the Y chromosome differed
between
the two species.
"This research shows that the Y chromosome isn't necessarily degrading, but is evolving very
fast,
said Professor Robin Lovell-Badge, of the National Institute for Medical Research in London, an
expert
on the Y chromosome. who was not involved in the study.
Dr Page likened the process to a home that is constantly under renovation.
"People are living in the house, but there's always some room that's being demolished and
reconstructed,
he said. "This is not the norm for the genome as a whole.
Several factors probably account for the rapid evolution of the Y chromosome.
First, the trick it uses to repair genes ' known as gene conversion ' is probably less
efficient than the repair mechanisms used elsewhere in the genome.
This allows new mutations to arise more often.
These mutations are then subject to greater selective pressure than the rest of
the genome ' because of the important role of the Y chromosome in sperm production.
Any advantageous mutations would be expected to be preserved as they boost fertility,
while deleterious ones would be rapidly flushed from the gene pool.
This is supported by the discovery that the parts of the chromosome involved in sperm
production are most different between humans and chimps.
Wes Warren, of Washington University in St Louis, Missouri, who contributed to the study,
said: "This work clearly shows that the Y is pretty ingenious at using different tools than the
rest of the genome to maintain diversity of genes. These findings demonstrate that our
knowledge
of the Y chromosome is still advancing.
Why the Y chromosome is a hotbed for evolution
Mark Henderson, Science Editor
The Y chromosome is often seen as the rotten corner of the human genome “ a place
of evolutionary decline that is slowly decaying and threatening the end of man. Reports
of its imminent demise, however, have been exaggerated.
Research has indicated that, far from stagnating, the male chromosome is a hotspot
of evolution that is changing more quickly than any other part of humanity's genetic code.
In most mammals the sex of offspring is determined by X and Y chromosomes.
Females have two XS, males have one X and one Y - with the Y making them male.
The Y was originally identical to the X, but over 300 million years it has shrunk, and is now
the smallest human chromosome.This is because it occurs on its own, and cannot swap
genes to maintain integrity. This decline has led scientists to suggest it would waste away
entirely in 125,000 years or so. This would mean the end of men, and probably of humanity.
But the first comparison of the human Y chromosome with its counterpart in chimpanzees
has revealed that they differ radically. The findings suggest that the Y chromosomes of
both are evolving rapidly and dynamically ' probably because of their critical roles in
reproduction
and have a vibrant future.
In the new research, which is published in the journal Nature, Dr David Page, of the
Massachusetts
Institute of Technology ' who first sequenced the Y chromosome in 2003 ' has now sequenced
the Y chromosome of the chimp, humanity's closest relative, and compared this with the human
version.
The scientists expected the two sequences to look very similar. However, while human and
chimp DNA
generally differ by less than 2 per cent, more than 30 per cent of the Y chromosome differed
between
the two species.
"This research shows that the Y chromosome isn't necessarily degrading, but is evolving very
fast,
said Professor Robin Lovell-Badge, of the National Institute for Medical Research in London, an
expert
on the Y chromosome. who was not involved in the study.
Dr Page likened the process to a home that is constantly under renovation.
"People are living in the house, but there's always some room that's being demolished and
reconstructed,
he said. "This is not the norm for the genome as a whole.
Several factors probably account for the rapid evolution of the Y chromosome.
First, the trick it uses to repair genes ' known as gene conversion ' is probably less
efficient than the repair mechanisms used elsewhere in the genome.
This allows new mutations to arise more often.
These mutations are then subject to greater selective pressure than the rest of
the genome ' because of the important role of the Y chromosome in sperm production.
Any advantageous mutations would be expected to be preserved as they boost fertility,
while deleterious ones would be rapidly flushed from the gene pool.
This is supported by the discovery that the parts of the chromosome involved in sperm
production are most different between humans and chimps.
Wes Warren, of Washington University in St Louis, Missouri, who contributed to the study,
said: "This work clearly shows that the Y is pretty ingenious at using different tools than the
rest of the genome to maintain diversity of genes. These findings demonstrate that our
knowledge
of the Y chromosome is still advancing.
The interesting
thing is the
feminist's
comments on this
article!!
"this research shows
that: how women are
superior. Men have
to EVOLVE for another
million years to reach
where we are now. "
"On the other hand,
who said that
evolution is always
good."
Jennifer said:
“Y chromosome is
some thing and men
are some thing else!!
there is no scientific
proved for any
relation between
them.”
But any how this are
the research's results :
“A new study
comparing the Y
chromosomes from
humans and
chimpanzees, our
nearest
living relatives, show
that they are about 30
percent different. That
is far greater than
the 2 percent
difference between
the rest of the human
genetic code and that
of the
chimp's, according to a
study appearing on
line, Wednesday in the
journal Nature.”
Women are very close
to CHAMPANZEE (98%
of their chromosomes)
and we are far away
(70%),
then think, where is
the main problem in
our relationship?
Try to explain it to a
woman!
I don't think they can
understand us.
thing is the
feminist's
comments on this
article!!
"this research shows
that: how women are
superior. Men have
to EVOLVE for another
million years to reach
where we are now. "
"On the other hand,
who said that
evolution is always
good."
Jennifer said:
“Y chromosome is
some thing and men
are some thing else!!
there is no scientific
proved for any
relation between
them.”
But any how this are
the research's results :
“A new study
comparing the Y
chromosomes from
humans and
chimpanzees, our
nearest
living relatives, show
that they are about 30
percent different. That
is far greater than
the 2 percent
difference between
the rest of the human
genetic code and that
of the
chimp's, according to a
study appearing on
line, Wednesday in the
journal Nature.”
Women are very close
to CHAMPANZEE (98%
of their chromosomes)
and we are far away
(70%),
then think, where is
the main problem in
our relationship?
Try to explain it to a
woman!
I don't think they can
understand us.
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