Discussion:
Ama physiology
(too old to reply)
Primum Sapienti
2024-02-05 21:35:58 UTC
Permalink
From 1967

Quite a number of interesting facts.

http://userhome.brooklyn.cuny.edu/anthro/jbeatty/CORESEA/AMA.pdf

The Diving Women of Korea and Japan

Some 30,000 of these breath-holding divers,
called ama, are employed in daily foraging
for food on the bottom of the sea.

Their performance is of particular interest
to the physiologist

"She carries a counterweight (of about 30 pounds)
to pull her to the bottom..."

"If she dives deeper than the level of maximum
lung compression (her "residual lung volume"),
she becomes subject to a painful lung squeeze;
moreover, because the hydrostatic pressure in
her blood vessels then exceeds the air
pressure in her lungs, the pulmonary
blood vessels may burst. "

"Lanphier has calculated that repeated dives to
depths of 120 feet, such as are performed by male
pearl divers in the Tuamotu Archipelago of the
South Pacific, can result in enough accumulation
of nitrogen in the blood to cause the bends
on ascent."

"To compensate for this loss the Korean diving
woman eats considerably more than her nondiving
sisters. The ama's daily food consumption amounts
to about 3,000 kilocalories, whereas the
average for nondiving Korean women of
comparable age is on the order of 2,000
kilocalories per day."

"They showed, for one thing, that with the same
thickness of subcutaneous fat, divers had less
heat loss than nondivers. This was taken to
indicate that the divers' fatty insulation is
supplemented by some kind of vascular adaptation
that restricts the loss of heat from the blood
vessels to the skin, pmticularly in the arms and
legs. Secondly, the observations disclosed that
in winter the diving women lose about half of
their subcutaneous fat (although nondivers do
not)."
Mario Petrinovic
2024-02-05 22:01:02 UTC
Permalink
Post by Primum Sapienti
From 1967
Quite a number of interesting facts.
http://userhome.brooklyn.cuny.edu/anthro/jbeatty/CORESEA/AMA.pdf
The Diving Women of Korea and Japan
Some 30,000 of these breath-holding divers,
called ama, are employed in daily foraging
for food on the bottom of the sea.
Their performance is of particular interest
to the physiologist
"She carries a counterweight (of about 30 pounds)
to pull her to the bottom..."
"If she dives deeper than the level of maximum
lung compression (her "residual lung volume"),
she becomes subject to a painful lung squeeze;
moreover, because the hydrostatic pressure in
her blood vessels then exceeds the air
pressure in her lungs, the pulmonary
blood vessels may burst. "
"Lanphier has calculated that repeated dives to
depths of 120 feet, such as are performed by male
pearl divers in the Tuamotu Archipelago of the
South Pacific, can result in enough accumulation
of nitrogen in the blood to cause the bends
on ascent."
"To compensate for this loss the Korean diving
woman eats considerably more than her nondiving
sisters. The ama's daily food consumption amounts
to about 3,000 kilocalories, whereas the
average for nondiving Korean women of
comparable age is on the order of 2,000
kilocalories per day."
"They showed, for one thing, that with the same
thickness of subcutaneous fat, divers had less
heat loss than nondivers. This was taken to
indicate that the divers' fatty insulation is
supplemented by some kind of vascular adaptation
that restricts the loss of heat from the blood
vessels to the skin, pmticularly in the arms and
legs. Secondly, the observations disclosed that
in winter the diving women lose about half of
their subcutaneous fat (although nondivers do
not)."
Of course, you misunderstood everything. They don't dive in winter, I
suppose. Their SC fat works better because they have the adaptation.
When you have adaptation to some environment, this is the proof that you
are adapted for that environment. If you wouldn't be adapted, you
wouldn't have the adaptation. I know that this is so hard for you to
understand, so, don't even try, just believe whatever you've been told,
you will not be able to understand anything with your own mind, anyway.
Primum Sapienti
2024-02-05 22:16:04 UTC
Permalink
 From 1967
Quite a number of interesting facts.
http://userhome.brooklyn.cuny.edu/anthro/jbeatty/CORESEA/AMA.pdf
The Diving Women of Korea and Japan
Some 30,000 of these breath-holding divers,
called ama, are employed in daily foraging
for food on the bottom of the sea.
Their performance is of particular interest
to the physiologist
"She carries a counterweight (of about 30 pounds)
to pull her to the bottom..."
"If she dives deeper than the level of maximum
lung compression (her "residual lung volume"),
she becomes subject to a painful lung squeeze;
moreover, because the hydrostatic pressure in
her blood vessels then exceeds the air
pressure in her lungs, the pulmonary
blood vessels may burst. "
"Lanphier has calculated that repeated dives to
depths of 120 feet, such as are performed by male
pearl divers in the Tuamotu Archipelago of the
South Pacific, can result in enough accumulation
of nitrogen in the blood to cause the bends
on ascent."
"To compensate for this loss the Korean diving
woman eats considerably more than her nondiving
sisters. The ama's daily food consumption amounts
to about 3,000 kilocalories, whereas the
average for nondiving Korean women of
comparable age is on the order of 2,000
kilocalories per day."
"They showed, for one thing, that with the same
thickness of subcutaneous fat, divers had less
heat loss than nondivers. This was taken to
indicate that the divers' fatty insulation is
supplemented by some kind of vascular adaptation
that restricts the loss of heat from the blood
vessels to the skin, pmticularly in the arms and
legs. Secondly, the observations disclosed that
in winter the diving women lose about half of
their subcutaneous fat (although nondivers do
not)."
        Of course, you misunderstood everything. They don't dive in
winter, I suppose. Their SC fat works better because they have the
adaptation. When you have adaptation to some environment, this is the proof
that you are adapted for that environment. If you wouldn't be adapted, you
wouldn't have the adaptation. I know that this is so hard for you to
understand, so, don't even try, just believe whatever you've been told, you
will not be able to understand anything with your own mind, anyway.
Yes, they DO dive in winter. It even says so in the
paragraph right above:

"in winter the diving women lose about half of
their subcutaneous fat"
Mario Petrinovic
2024-02-06 01:10:44 UTC
Permalink
Post by Primum Sapienti
 From 1967
Quite a number of interesting facts.
http://userhome.brooklyn.cuny.edu/anthro/jbeatty/CORESEA/AMA.pdf
The Diving Women of Korea and Japan
Some 30,000 of these breath-holding divers,
called ama, are employed in daily foraging
for food on the bottom of the sea.
Their performance is of particular interest
to the physiologist
"She carries a counterweight (of about 30 pounds)
to pull her to the bottom..."
"If she dives deeper than the level of maximum
lung compression (her "residual lung volume"),
she becomes subject to a painful lung squeeze;
moreover, because the hydrostatic pressure in
her blood vessels then exceeds the air
pressure in her lungs, the pulmonary
blood vessels may burst. "
"Lanphier has calculated that repeated dives to
depths of 120 feet, such as are performed by male
pearl divers in the Tuamotu Archipelago of the
South Pacific, can result in enough accumulation
of nitrogen in the blood to cause the bends
on ascent."
"To compensate for this loss the Korean diving
woman eats considerably more than her nondiving
sisters. The ama's daily food consumption amounts
to about 3,000 kilocalories, whereas the
average for nondiving Korean women of
comparable age is on the order of 2,000
kilocalories per day."
"They showed, for one thing, that with the same
thickness of subcutaneous fat, divers had less
heat loss than nondivers. This was taken to
indicate that the divers' fatty insulation is
supplemented by some kind of vascular adaptation
that restricts the loss of heat from the blood
vessels to the skin, pmticularly in the arms and
legs. Secondly, the observations disclosed that
in winter the diving women lose about half of
their subcutaneous fat (although nondivers do
not)."
         Of course, you misunderstood everything. They don't dive in
winter, I suppose. Their SC fat works better because they have the
adaptation. When you have adaptation to some environment, this is the
proof that you are adapted for that environment. If you wouldn't be
adapted, you wouldn't have the adaptation. I know that this is so hard
for you to understand, so, don't even try, just believe whatever
you've been told, you will not be able to understand anything with
your own mind, anyway.
Yes, they DO dive in winter. It even says so in the
"in winter the diving women lose about half of
their subcutaneous fat"
No, this doesn't mean that they dive in winter. The guy separates
"diving women" and "non diving women". Diving women dive, and do this
for living, but it isn't said whether they dive whole year, or only when
waters are warmer. One would presume that they don't dive when waters
are too cold. "Non diving women" on the other side, can dive
recreationally, but they are not doing it as a job.
Ok, I took a look at Wikipedia.
First, it is women who are doing diving (as opposed to men), because
they have better fat distribution than men. So, fat has the major role
here. It is known that men have muscle tissue, while women have fat.
Second, it is said that there is a diving season. So, they are not
diving whole year long. One would presume that the season is in
favorable conditions, not in winter.
Third, in Wikipedia they say that those women actually lose weight
during diving season. Which could be because of physical strain, since
they probably don't work as hard out of the season.
Mario Petrinovic
2024-02-06 01:27:57 UTC
Permalink
Post by Primum Sapienti
 From 1967
Quite a number of interesting facts.
http://userhome.brooklyn.cuny.edu/anthro/jbeatty/CORESEA/AMA.pdf
The Diving Women of Korea and Japan
Some 30,000 of these breath-holding divers,
called ama, are employed in daily foraging
for food on the bottom of the sea.
Their performance is of particular interest
to the physiologist
"She carries a counterweight (of about 30 pounds)
to pull her to the bottom..."
"If she dives deeper than the level of maximum
lung compression (her "residual lung volume"),
she becomes subject to a painful lung squeeze;
moreover, because the hydrostatic pressure in
her blood vessels then exceeds the air
pressure in her lungs, the pulmonary
blood vessels may burst. "
"Lanphier has calculated that repeated dives to
depths of 120 feet, such as are performed by male
pearl divers in the Tuamotu Archipelago of the
South Pacific, can result in enough accumulation
of nitrogen in the blood to cause the bends
on ascent."
"To compensate for this loss the Korean diving
woman eats considerably more than her nondiving
sisters. The ama's daily food consumption amounts
to about 3,000 kilocalories, whereas the
average for nondiving Korean women of
comparable age is on the order of 2,000
kilocalories per day."
"They showed, for one thing, that with the same
thickness of subcutaneous fat, divers had less
heat loss than nondivers. This was taken to
indicate that the divers' fatty insulation is
supplemented by some kind of vascular adaptation
that restricts the loss of heat from the blood
vessels to the skin, pmticularly in the arms and
legs. Secondly, the observations disclosed that
in winter the diving women lose about half of
their subcutaneous fat (although nondivers do
not)."
         Of course, you misunderstood everything. They don't dive in
winter, I suppose. Their SC fat works better because they have the
adaptation. When you have adaptation to some environment, this is the
proof that you are adapted for that environment. If you wouldn't be
adapted, you wouldn't have the adaptation. I know that this is so
hard for you to understand, so, don't even try, just believe whatever
you've been told, you will not be able to understand anything with
your own mind, anyway.
Yes, they DO dive in winter. It even says so in the
"in winter the diving women lose about half of
their subcutaneous fat"
        No, this doesn't mean that they dive in winter. The guy
separates "diving women" and "non diving women". Diving women dive, and
do this for living, but it isn't said whether they dive whole year, or
only when waters are warmer. One would presume that they don't dive when
waters are too cold. "Non diving women" on the other side, can dive
recreationally, but they are not doing it as a job.
        Ok, I took a look at Wikipedia.
        First, it is women who are doing diving (as opposed to men),
because they have better fat distribution than men. So, fat has the
major role here. It is known that men have muscle tissue, while women
have fat.
        Second, it is said that there is a diving season. So, they are
not diving whole year long. One would presume that the season is in
favorable conditions, not in winter.
        Third, in Wikipedia they say that those women actually lose
weight during diving season. Which could be because of physical strain,
since they probably don't work as hard out of the season.
OK, I found out, diving season is strictly from March to 14th of
September. They don't dive in winter.
Primum Sapienti
2024-02-06 01:32:12 UTC
Permalink
Post by Primum Sapienti
 From 1967
Quite a number of interesting facts.
http://userhome.brooklyn.cuny.edu/anthro/jbeatty/CORESEA/AMA.pdf
The Diving Women of Korea and Japan
Some 30,000 of these breath-holding divers,
called ama, are employed in daily foraging
for food on the bottom of the sea.
Their performance is of particular interest
to the physiologist
"She carries a counterweight (of about 30 pounds)
to pull her to the bottom..."
"If she dives deeper than the level of maximum
lung compression (her "residual lung volume"),
she becomes subject to a painful lung squeeze;
moreover, because the hydrostatic pressure in
her blood vessels then exceeds the air
pressure in her lungs, the pulmonary
blood vessels may burst. "
"Lanphier has calculated that repeated dives to
depths of 120 feet, such as are performed by male
pearl divers in the Tuamotu Archipelago of the
South Pacific, can result in enough accumulation
of nitrogen in the blood to cause the bends
on ascent."
"To compensate for this loss the Korean diving
woman eats considerably more than her nondiving
sisters. The ama's daily food consumption amounts
to about 3,000 kilocalories, whereas the
average for nondiving Korean women of
comparable age is on the order of 2,000
kilocalories per day."
"They showed, for one thing, that with the same
thickness of subcutaneous fat, divers had less
heat loss than nondivers. This was taken to
indicate that the divers' fatty insulation is
supplemented by some kind of vascular adaptation
that restricts the loss of heat from the blood
vessels to the skin, pmticularly in the arms and
legs. Secondly, the observations disclosed that
in winter the diving women lose about half of
their subcutaneous fat (although nondivers do
not)."
         Of course, you misunderstood everything. They don't dive in
winter, I suppose. Their SC fat works better because they have the
adaptation. When you have adaptation to some environment, this is the
proof that you are adapted for that environment. If you wouldn't be
adapted, you wouldn't have the adaptation. I know that this is so hard
for you to understand, so, don't even try, just believe whatever you've
been told, you will not be able to understand anything with your own
mind, anyway.
Yes, they DO dive in winter. It even says so in the
"in winter the diving women lose about half of
their subcutaneous fat"
        No, this doesn't mean that they dive in winter. The guy separates
"diving women" and "non diving women". Diving women dive, and do this for
living, but it isn't said whether they dive whole year, or only when waters
are warmer. One would presume that they don't dive when waters are too
cold. "Non diving women" on the other side, can dive recreationally, but
they are not doing it as a job.
Follow the link.

"By and large the divers wear minimal clothing,
often only a loincloth, during their work in
the water. Even in winter the Korean divers wear
only cotton bathing suits. In Japan some ama
have recently adopted foam-rubber suits, but most
of the diving women cannot afford this luxury."

"Even in winter"

"In the last analysis the amount of time one can
spend in the water, even without holding one's
breath, is limited by the loss of body heat. For
the working ama this is a critical factor,
affecting the length of their working day both in
summer and in winter."

"in winter"

"In both seasons at the end of a single diving
shift (40 minutes in the summer, 25 minutes in
winter) the deep-body temperature was found to be
reduced from the normal 98.6 degrees F. to 95
degrees or less."

"in both seasons" "in winter"

etc
        Ok, I took a look at Wikipedia.
This wiki article (just to be clear)

https://en.wikipedia.org/wiki/Ama_(diving)
        First, it is women who are doing diving (as opposed to men),
because they have better fat distribution than men. So, fat has the major
role here. It is known that men have muscle tissue, while women have fat.
aa says they should really fat.
        Second, it is said that there is a diving season. So, they are not
diving whole year long. One would presume that the season is in favorable
conditions, not in winter.
Yes, they are. That wiki page says

"The ama were expected to endure harsh
conditions while diving, such as freezing
temperatures and great pressures from the
depths of the sea."

"freezing"
        Third, in Wikipedia they say that those women actually lose weight
during diving season. Which could be because of physical strain, since they
probably don't work as hard out of the season.
Which is what I said. aa says the fat is supposed to
keep them warm. It doesn't if that activity means they
lose it.
Mario Petrinovic
2024-02-06 03:15:44 UTC
Permalink
Post by Primum Sapienti
Post by Primum Sapienti
 From 1967
Quite a number of interesting facts.
http://userhome.brooklyn.cuny.edu/anthro/jbeatty/CORESEA/AMA.pdf
The Diving Women of Korea and Japan
Some 30,000 of these breath-holding divers,
called ama, are employed in daily foraging
for food on the bottom of the sea.
Their performance is of particular interest
to the physiologist
"She carries a counterweight (of about 30 pounds)
to pull her to the bottom..."
"If she dives deeper than the level of maximum
lung compression (her "residual lung volume"),
she becomes subject to a painful lung squeeze;
moreover, because the hydrostatic pressure in
her blood vessels then exceeds the air
pressure in her lungs, the pulmonary
blood vessels may burst. "
"Lanphier has calculated that repeated dives to
depths of 120 feet, such as are performed by male
pearl divers in the Tuamotu Archipelago of the
South Pacific, can result in enough accumulation
of nitrogen in the blood to cause the bends
on ascent."
"To compensate for this loss the Korean diving
woman eats considerably more than her nondiving
sisters. The ama's daily food consumption amounts
to about 3,000 kilocalories, whereas the
average for nondiving Korean women of
comparable age is on the order of 2,000
kilocalories per day."
"They showed, for one thing, that with the same
thickness of subcutaneous fat, divers had less
heat loss than nondivers. This was taken to
indicate that the divers' fatty insulation is
supplemented by some kind of vascular adaptation
that restricts the loss of heat from the blood
vessels to the skin, pmticularly in the arms and
legs. Secondly, the observations disclosed that
in winter the diving women lose about half of
their subcutaneous fat (although nondivers do
not)."
         Of course, you misunderstood everything. They don't dive in
winter, I suppose. Their SC fat works better because they have the
adaptation. When you have adaptation to some environment, this is
the proof that you are adapted for that environment. If you wouldn't
be adapted, you wouldn't have the adaptation. I know that this is so
hard for you to understand, so, don't even try, just believe
whatever you've been told, you will not be able to understand
anything with your own mind, anyway.
Yes, they DO dive in winter. It even says so in the
"in winter the diving women lose about half of
their subcutaneous fat"
         No, this doesn't mean that they dive in winter. The guy
separates "diving women" and "non diving women". Diving women dive,
and do this for living, but it isn't said whether they dive whole
year, or only when waters are warmer. One would presume that they
don't dive when waters are too cold. "Non diving women" on the other
side, can dive recreationally, but they are not doing it as a job.
Follow the link.
"By and large the divers wear minimal clothing,
often only a loincloth, during their work in
the water. Even in winter the Korean divers wear
only cotton bathing suits. In Japan some ama
have recently adopted foam-rubber suits, but most
of the diving women cannot afford this luxury."
"Even in winter"
"In the last analysis the amount of time one can
spend in the water, even without holding one's
breath, is limited by the loss of body heat. For
the working ama this is a critical factor,
affecting the length of their working day both in
summer and in winter."
"in winter"
"In both seasons at the end of a single diving
shift (40 minutes in the summer, 25 minutes in
winter) the deep-body temperature was found to be
reduced from the normal 98.6 degrees F. to 95
degrees or less."
"in both seasons" "in winter"
etc
         Ok, I took a look at Wikipedia.
This wiki article (just to be clear)
https://en.wikipedia.org/wiki/Ama_(diving)
         First, it is women who are doing diving (as opposed to men),
because they have better fat distribution than men. So, fat has the
major role here. It is known that men have muscle tissue, while women
have fat.
aa says they should really fat.
         Second, it is said that there is a diving season. So, they
are not diving whole year long. One would presume that the season is
in favorable conditions, not in winter.
Yes, they are. That wiki page says
"The ama were expected to endure harsh
conditions while diving, such as freezing
temperatures and great pressures from the
depths of the sea."
"freezing"
         Third, in Wikipedia they say that those women actually lose
weight during diving season. Which could be because of physical
strain, since they probably don't work as hard out of the season.
Which is what I said. aa says the fat is supposed to
keep them warm. It doesn't if that activity means they
lose it.
Ah, I didn't bother with your link, since I saw it is from 1967., but
it looks like it is pretty detailed. Well, my info is recent, and I
believe it is about Korean ama. Anyway, I will not bother about it
still, it is pretty clear that SC fat is for aquatic purposes. I mean,
as far as I can tell, all those amas are women. Which doesn't explain
everything (since ama diving wasn't economical, men would do something
that is economical), but explains enough. You don't know much about SC
fat, go and read something, it is absolutely clear that it is for
aquatic lifestyle. And it isn't you that I am worried about, this should
be absolutely clear to scientific community, yet it isn't, and this is
what makes people like you to behave like you behave.
Primum Sapienti
2024-02-06 05:05:37 UTC
Permalink
Post by Primum Sapienti
Post by Primum Sapienti
 From 1967
Quite a number of interesting facts.
http://userhome.brooklyn.cuny.edu/anthro/jbeatty/CORESEA/AMA.pdf
The Diving Women of Korea and Japan
Some 30,000 of these breath-holding divers,
called ama, are employed in daily foraging
for food on the bottom of the sea.
Their performance is of particular interest
to the physiologist
"She carries a counterweight (of about 30 pounds)
to pull her to the bottom..."
"If she dives deeper than the level of maximum
lung compression (her "residual lung volume"),
she becomes subject to a painful lung squeeze;
moreover, because the hydrostatic pressure in
her blood vessels then exceeds the air
pressure in her lungs, the pulmonary
blood vessels may burst. "
"Lanphier has calculated that repeated dives to
depths of 120 feet, such as are performed by male
pearl divers in the Tuamotu Archipelago of the
South Pacific, can result in enough accumulation
of nitrogen in the blood to cause the bends
on ascent."
"To compensate for this loss the Korean diving
woman eats considerably more than her nondiving
sisters. The ama's daily food consumption amounts
to about 3,000 kilocalories, whereas the
average for nondiving Korean women of
comparable age is on the order of 2,000
kilocalories per day."
"They showed, for one thing, that with the same
thickness of subcutaneous fat, divers had less
heat loss than nondivers. This was taken to
indicate that the divers' fatty insulation is
supplemented by some kind of vascular adaptation
that restricts the loss of heat from the blood
vessels to the skin, pmticularly in the arms and
legs. Secondly, the observations disclosed that
in winter the diving women lose about half of
their subcutaneous fat (although nondivers do
not)."
         Of course, you misunderstood everything. They don't dive in
winter, I suppose. Their SC fat works better because they have the
adaptation. When you have adaptation to some environment, this is the
proof that you are adapted for that environment. If you wouldn't be
adapted, you wouldn't have the adaptation. I know that this is so hard
for you to understand, so, don't even try, just believe whatever
you've been told, you will not be able to understand anything with
your own mind, anyway.
Yes, they DO dive in winter. It even says so in the
"in winter the diving women lose about half of
their subcutaneous fat"
         No, this doesn't mean that they dive in winter. The guy
separates "diving women" and "non diving women". Diving women dive, and
do this for living, but it isn't said whether they dive whole year, or
only when waters are warmer. One would presume that they don't dive when
waters are too cold. "Non diving women" on the other side, can dive
recreationally, but they are not doing it as a job.
Follow the link.
"By and large the divers wear minimal clothing,
often only a loincloth, during their work in
the water. Even in winter the Korean divers wear
only cotton bathing suits. In Japan some ama
have recently adopted foam-rubber suits, but most
of the diving women cannot afford this luxury."
"Even in winter"
"In the last analysis the amount of time one can
spend in the water, even without holding one's
breath, is limited by the loss of body heat. For
the working ama this is a critical factor,
affecting the length of their working day both in
summer and in winter."
"in winter"
"In both seasons at the end of a single diving
shift (40 minutes in the summer, 25 minutes in
winter) the deep-body temperature was found to be
reduced from the normal 98.6 degrees F. to 95
degrees or less."
"in both seasons" "in winter"
etc
         Ok, I took a look at Wikipedia.
This wiki article (just to be clear)
https://en.wikipedia.org/wiki/Ama_(diving)
         First, it is women who are doing diving (as opposed to men),
because they have better fat distribution than men. So, fat has the
major role here. It is known that men have muscle tissue, while women
have fat.
aa says they should really fat.
         Second, it is said that there is a diving season. So, they are
not diving whole year long. One would presume that the season is in
favorable conditions, not in winter.
Yes, they are. That wiki page says
"The ama were expected to endure harsh
conditions while diving, such as freezing
temperatures and great pressures from the
depths of the sea."
"freezing"
         Third, in Wikipedia they say that those women actually lose
weight during diving season. Which could be because of physical strain,
since they probably don't work as hard out of the season.
Which is what I said. aa says the fat is supposed to
keep them warm. It doesn't if that activity means they
lose it.
        Ah, I didn't bother with your link, since I saw it is from 1967.,
Which means that they have modified their
practice. From the wiki link

"The number of ama continue to dwindle as this
ancient technique becomes less and less practiced,
due to disinterest in the new generation of women
and the dwindling demand for their activity. In
the 1940s, 6,000 ama were reported active along
the coasts of Japan, while today ama practice at
numbers more along the scale of 60 or 70 divers
in a generation."

To say that the practice is dying out would be fairly accurate.
but it looks like it is pretty detailed. Well, my info is recent, and I
believe it is about Korean ama. Anyway, I will not bother about it still,
it is pretty clear that SC fat is for aquatic purposes. I mean, as far as I
can tell, all those amas are women. Which doesn't explain everything (since
ama diving wasn't economical, men would do something that is economical),
but explains enough. You don't know much about SC fat, go and read
something, it is absolutely clear that it is for aquatic lifestyle. And it
isn't you that I am worried about, this should be absolutely clear to
scientific community, yet it isn't, and this is what makes people like you
to behave like you behave.
Primum Sapienti
2024-02-15 01:56:33 UTC
Permalink
Post by Marc Verhaegen
Post by Primum Sapienti
From 1967
Quite a number of interesting facts.
http://userhome.brooklyn.cuny.edu/anthro/jbeatty/CORESEA/AMA.pdf
The Diving Women of Korea and Japan
Some 30,000 of these breath-holding divers,
called ama, are employed in daily foraging
for food on the bottom of the sea.
Yes, voluntary breath-holding is exclusively seen in (semi)aquatic
mammals.

You mean like those diving puppies? Crab eating macaques? ;)
Post by Marc Verhaegen
Post by Primum Sapienti
Their performance is of particular interest to the physiologist
"She carries a counterweight (of about 30 pounds)
to pull her to the bottom..."
very thick & heavy skeleton (probably more brittle: too much
calcium), exclusively seen in tetrapods that regularly dive for littoral
foods
Post by Marc Verhaegen
= diving-adaptation in slow+shallow-diving, e.g. Sirenia, earliest
fossil Cetacea etc.
Post by Marc Verhaegen
(Not vice versa: deep+fast divers such as present-day Cetacea have
light skeletons!)

Ama look nothing like that.
Post by Marc Verhaegen
Post by Primum Sapienti
"If she dives deeper than the level of maximum
lung compression (her "residual lung volume"),
she becomes subject to a painful lung squeeze;
moreover, because the hydrostatic pressure in
her blood vessels then exceeds the air
pressure in her lungs, the pulmonary
blood vessels may burst."
"Lanphier has calculated that repeated dives to
depths of 120 feet, such as are performed by male
pearl divers in the Tuamotu Archipelago of the
South Pacific, can result in enough accumulation
of nitrogen in the blood to cause the bends
on ascent."
"To compensate for this loss the Korean diving
woman eats considerably more than her nondiving
sisters. The ama's daily food consumption amounts
to about 3000 kcal, whereas the
average for non-diving Korean women of
comparable age is on the order of 2000 kcal/day."
"They showed, for one thing, that with the same
thickness of subcutaneous fat, divers had less
heat loss than non-divers. This was taken to
indicate that the divers' fatty insulation is
supplemented by some kind of vascular adaptation
that restricts the loss of heat from the blood
vessels to the skin, particularly in the arms and
legs. Secondly, the observations disclosed that
in winter the diving women lose about half of
their subcutaneous fat (although non-divers do
not)."
Yes, thanks a lot, this nicely confirms we had frequently-diving
ancestors still in the Pleistocene:

Long legged, sleek, trim, little fat ;)
JTEM
2024-03-06 19:45:47 UTC
Permalink
Post by Primum Sapienti
You mean like those diving puppies? Crab eating macaques? ;)
https://archives.cmas.org/apnoea/about-2012032621

Skip down to "Physiology of free-diving." And of course
I say that knowing there's little chance that you will,
and even less chance that you'll grasp a word of it.

We should do this more often. Seriously. It's fun.
--
http://jtem.tumblr.com
Marc Verhaegen
2024-02-06 14:01:05 UTC
Permalink
Post by Primum Sapienti
From 1967
Quite a number of interesting facts.
http://userhome.brooklyn.cuny.edu/anthro/jbeatty/CORESEA/AMA.pdf
The Diving Women of Korea and Japan
Some 30,000 of these breath-holding divers,
called ama, are employed in daily foraging
for food on the bottom of the sea.
Yes, voluntary breath-holding is exclusively seen in (semi)aquatic mammals.
Post by Primum Sapienti
Their performance is of particular interest to the physiologist
"She carries a counterweight (of about 30 pounds)
to pull her to the bottom..."
Yes, that's why H.erectus had pachyosteosclerosis (google):
very thick & heavy skeleton (probably more brittle: too much calcium), exclusively seen in tetrapods that regularly dive for littoral foods
= diving-adaptation in slow+shallow-diving, e.g. Sirenia, earliest fossil Cetacea etc.
(Not vice versa: deep+fast divers such as present-day Cetacea have light skeletons!)
Post by Primum Sapienti
"If she dives deeper than the level of maximum
lung compression (her "residual lung volume"),
she becomes subject to a painful lung squeeze;
moreover, because the hydrostatic pressure in
her blood vessels then exceeds the air
pressure in her lungs, the pulmonary
blood vessels may burst."
"Lanphier has calculated that repeated dives to
depths of 120 feet, such as are performed by male
pearl divers in the Tuamotu Archipelago of the
South Pacific, can result in enough accumulation
of nitrogen in the blood to cause the bends
on ascent."
"To compensate for this loss the Korean diving
woman eats considerably more than her nondiving
sisters. The ama's daily food consumption amounts
to about 3000 kcal, whereas the
average for non-diving Korean women of
comparable age is on the order of 2000 kcal/day."
"They showed, for one thing, that with the same
thickness of subcutaneous fat, divers had less
heat loss than non-divers. This was taken to
indicate that the divers' fatty insulation is
supplemented by some kind of vascular adaptation
that restricts the loss of heat from the blood
vessels to the skin, particularly in the arms and
legs. Secondly, the observations disclosed that
in winter the diving women lose about half of
their subcutaneous fat (although non-divers do
not)."
Yes, thanks a lot, this nicely confirms we had frequently-diving ancestors still in the Pleistocene:

Ape+human evolution, recent insights, google e.g.
- David Attenborough Marc Verhaegen
- Gondwanatalks Verhaegen
- aquarboreal
- Mario Vaneechoutte cs 2024 Nature Anthropology 2,10007
“Have we been barking up the wrong ancestral tree?
Australopithecines are probably not our ancestors”
open access https://www.sciepublish.com/article/pii/94
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