One of the few valuable papers Lasisi found is a 1973 study in the American Journal of Physical Anthropology. In it, Daniel Hrdy, of Harvard University, loosely described a methodology to quantify the shape of a hair curl, which he applied to seven groups of people around the world. Imperfect as it was, it was the starting point Lasisi was looking for. She built off his research, honing a methodology for fitting hair fibers to a circle to determine curvature and publishing her results in the American Journal of Biological Anthropology and Nature’s Scientific Reports.

Jablonski says Lasisi’s work suggests how, just as melanated skin protects against UV rays, tightly curled hairs also protect humans from the sun. Tight curls create lofted, airy ventilation structures for the head, allowing it to breathe [sweat] while providing extra protection from solar radiation. That was important for our newly bipedal human ancestors, she says, and you can’t do that with flat hair.

Read more about misconceptions in racial classification: “Race Is Real, But It’s Not Genetic”

Sapiens.org

On Thursday 10 March 2022 at 14:42:56 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:

> Jablonski says Lasisi’s work suggests how, just as melanated skin
> protects against UV rays, tightly curled hairs also protect humans
> from the sun.

So what's the need for that extremely
expensive hair? If melanated naked skin
protects against UV rays, why have that
extraordinary hair? ('Extraordinary' in
that no other mammal has anything
like it.)

> Tight curls create lofted, airy ventilation structures for the head,
> allowing it to breathe [sweat] while providing extra protection
> from solar radiation. That was important for our newly bipedal
> human ancestors, she says, and you cant do that with flat hair.

Can't do what . . exactly? There's no
problem with sweating elsewhere on
the body.

What's the need for that dense, tightly-
curled hair?

Don't pretend you have an answer
when all you can present is verbiage.
That's deceptive politics, not science.

On Thursday, March 10, 2022 at 3:07:28 PM UTC-5, Paul Crowley wrote:
> On Thursday 10 March 2022 at 14:42:56 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:
>
> > Jablonski says Lasisi’s work suggests how, just as melanated skin
> > protects against UV rays, tightly curled hairs also protect humans
> > from the sun.
> So what's the need for that extremely
> expensive hair? If melanated naked skin
> protects against UV rays, why have that
> extraordinary hair? ('Extraordinary' in
> that no other mammal has anything
> like it.)

Melanin in skin: stops ultraviolet light penetration beyond the (dead) epidermis layer.
Melanin in hair: stops infrared light (heat) penetration at the (coiled dead) hair layer, which reduces the temperature of the head (including brain and blood vessels).
Homo's large brain has large heat production, sweating depends on evaporation, in perpetually hot humid climates sweating is more effective with tightly coiled but lofty hair than with damp flat hair clinging to the scalp.

> > Tight curls create lofted, airy ventilation structures for the head,
> > allowing it to breathe [sweat] while providing extra protection
> > from solar radiation. That was important for our newly bipedal
> > human ancestors, she says, and you can t do that with flat hair.
> Can't do what . . exactly? There's no
> problem with sweating elsewhere on
> the body.
>
> What's the need for that dense, tightly-
> curled hair?
>
> Don't pretend you have an answer
> when all you can present is verbiage.
> That's deceptive politics, not science.

On Thursday, March 10, 2022 at 7:11:44 PM UTC-5, DD'eDeN aka note/nickname/alas_my_loves wrote:
> On Thursday, March 10, 2022 at 3:07:28 PM UTC-5, Paul Crowley wrote:
> > On Thursday 10 March 2022 at 14:42:56 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:
> >
> > > Jablonski says Lasisi’s work suggests how, just as melanated skin
> > > protects against UV rays, tightly curled hairs also protect humans
> > > from the sun.
> > So what's the need for that extremely
> > expensive hair? If melanated naked skin
> > protects against UV rays, why have that
> > extraordinary hair? ('Extraordinary' in
> > that no other mammal has anything
> > like it.)
> Melanin in skin: stops ultraviolet light penetration beyond the (dead) epidermis layer.
> Melanin in hair: stops infrared light (heat) penetration at the (coiled dead) hair layer, which reduces the temperature of the head (including brain and blood vessels).
> Homo's large brain has large heat production, sweating depends on evaporation, in perpetually hot humid climates sweating is more effective with tightly coiled but lofty hair than with damp flat hair clinging to the scalp.

Gareth Morgan:
"In plain English, body heat is generated by mitochondria. Normal cells have between 2 and a couple of thousand mitochondria. Heart cells have around 5,000 but brain cells have an estimated two million mitochondria per cell.
The brain is a colossally effective furnace. This is important because the heart is the most vulnerable organ in the human body to cold. The blood from the brain, which comes out much hotter than it goes in, goes directly to the heart. In terms of natural selection this is very much the difference between rapid death from hypothermic heart failure and a chilly dip."

> > > Tight curls create lofted, airy ventilation structures for the head,
> > > allowing it to breathe [sweat] while providing extra protection
> > > from solar radiation. That was important for our newly bipedal
> > > human ancestors, she says, and you can t do that with flat hair.
> > Can't do what . . exactly? There's no
> > problem with sweating elsewhere on
> > the body.
> >
> > What's the need for that dense, tightly-
> > curled hair?
> >
> > Don't pretend you have an answer
> > when all you can present is verbiage.
> > That's deceptive politics, not science.

On Sunday, March 13, 2022 at 6:31:51 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
> On Thursday, March 10, 2022 at 7:11:44 PM UTC-5, DD'eDeN aka note/nickname/alas_my_loves wrote:
> > On Thursday, March 10, 2022 at 3:07:28 PM UTC-5, Paul Crowley wrote:
> > > On Thursday 10 March 2022 at 14:42:56 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:
> > >
> > > > Jablonski says Lasisi’s work suggests how, just as melanated skin
> > > > protects against UV rays, tightly curled hairs also protect humans
> > > > from the sun.
> > > So what's the need for that extremely
> > > expensive hair? If melanated naked skin
> > > protects against UV rays, why have that
> > > extraordinary hair? ('Extraordinary' in
> > > that no other mammal has anything
> > > like it.)
> > Melanin in skin: stops ultraviolet light penetration beyond the (dead) epidermis layer.
> > Melanin in hair: stops infrared light (heat) penetration at the (coiled dead) hair layer, which reduces the temperature of the head (including brain and blood vessels).
> > Homo's large brain has large heat production, sweating depends on evaporation, in perpetually hot humid climates sweating is more effective with tightly coiled but lofty hair than with damp flat hair clinging to the scalp..
> Gareth Morgan:
> "In plain English, body heat is generated by mitochondria. Normal cells have between 2 and a couple of thousand mitochondria. Heart cells have around 5,000 but brain cells have an estimated two million mitochondria per cell..
> The brain is a colossally effective furnace. This is important because the heart is the most vulnerable organ in the human body to cold. The blood from the brain, which comes out much hotter than it goes in, goes directly to the heart. In terms of natural selection this is very much the difference between rapid death from hypothermic heart failure and a chilly dip."
> > > > Tight curls create lofted, airy ventilation structures for the head,
> > > > allowing it to breathe [sweat] while providing extra protection
> > > > from solar radiation. That was important for our newly bipedal
> > > > human ancestors, she says, and you can t do that with flat hair.
> > > Can't do what . . exactly? There's no
> > > problem with sweating elsewhere on
> > > the body.
> > >
> > > What's the need for that dense, tightly-
> > > curled hair?
> > >
> > > Don't pretend you have an answer
> > > when all you can present is verbiage.
> > > That's deceptive politics, not science.

No response from PC, perhaps my explanation is too "political".
The human brain has multiples of multiples of sensory processors powered by mitochondrial batteries, theis produced heat as a result, much of which keeps the core warm, while always releasing some to the body surface which keeps the surface cool. Humans reduced the fur coat when adapting to sheltered dwelling, as it no longer was needed. Coiled hair allowed cooling while blocking IR.

On Sunday, March 13, 2022 at 11:06:13 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
> On Sunday, March 13, 2022 at 6:31:51 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
> > On Thursday, March 10, 2022 at 7:11:44 PM UTC-5, DD'eDeN aka note/nickname/alas_my_loves wrote:
> > > On Thursday, March 10, 2022 at 3:07:28 PM UTC-5, Paul Crowley wrote:
> > > > On Thursday 10 March 2022 at 14:42:56 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:
> > > >
> > > > > Jablonski says Lasisi’s work suggests how, just as melanated skin
> > > > > protects against UV rays, tightly curled hairs also protect humans
> > > > > from the sun.
> > > > So what's the need for that extremely
> > > > expensive hair? If melanated naked skin
> > > > protects against UV rays, why have that
> > > > extraordinary hair? ('Extraordinary' in
> > > > that no other mammal has anything
> > > > like it.)
> > > Melanin in skin: stops ultraviolet light penetration beyond the (dead) epidermis layer.
> > > Melanin in hair: stops infrared light (heat) penetration at the (coiled dead) hair layer, which reduces the temperature of the head (including brain and blood vessels).
> > > Homo's large brain has large heat production, sweating depends on evaporation, in perpetually hot humid climates sweating is more effective with tightly coiled but lofty hair than with damp flat hair clinging to the scalp.
> > Gareth Morgan:
> > "In plain English, body heat is generated by mitochondria. Normal cells have between 2 and a couple of thousand mitochondria. Heart cells have around 5,000 but brain cells have an estimated two million mitochondria per cell.
> > The brain is a colossally effective furnace. This is important because the heart is the most vulnerable organ in the human body to cold. The blood from the brain, which comes out much hotter than it goes in, goes directly to the heart. In terms of natural selection this is very much the difference between rapid death from hypothermic heart failure and a chilly dip."
> > > > > Tight curls create lofted, airy ventilation structures for the head,
> > > > > allowing it to breathe [sweat] while providing extra protection
> > > > > from solar radiation. That was important for our newly bipedal
> > > > > human ancestors, she says, and you can t do that with flat hair.
> > > > Can't do what . . exactly? There's no
> > > > problem with sweating elsewhere on
> > > > the body.
> > > >
> > > > What's the need for that dense, tightly-
> > > > curled hair?
> > > >
> > > > Don't pretend you have an answer
> > > > when all you can present is verbiage.
> > > > That's deceptive politics, not science.
> No response from PC, perhaps my explanation is too "political".
> The human brain has multiples of multiples of sensory processors powered by mitochondrial batteries, theis produced heat as a result, much of which keeps the core warm, while always releasing some to the body surface which keeps the surface cool. Humans reduced the fur coat when adapting to sheltered dwelling, as it no longer was needed. Coiled hair allowed cooling while blocking IR.

Supercomputers and data centers produce huge amounts of heat, now often liquid cooled, some approach the heat exhaust level of a nuclear fission plant..

https://www.3m.com/3M/en_US/particles/all-articles/article-detail/~/how-to-cool-supercomputers-3m-novec-liquid-immersion-cooling/?storyid=870afaa0-8c04-4442-aad7-fece0187fac0

https://mainichi.jp/english/articles/20210220/p2a/00m/0na/037000c

In the computing room on the third floor of the building housing Fugaku, 432 racks hold over 160,000 central processing units, which generate heat when they operate. The heat density can rise to over 100 kilowatts per square meter. This is like having 100 household electric heaters operating within a 1-meter-square space.

To make sure the CPUs can run efficiently, they must be kept under 30 degrees Celsius, but without cooling, their temperature would rise above 100 C in a matter of seconds. To prevent this, the supercomputer is equipped with a large water-based liquid cooling unit. The cooling system has primary and secondary branch pipes through which water flows to remove heat from the CPUs.
-

Blood carries heat away from the brain, the heart pumps hot blood throughout the body. The head is not "for heat storage".

On Sunday 13 March 2022 at 22:31:51 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:

>> So what's the need for that extremely
>> expensive hair? If melanated naked skin
>> protects against UV rays, why have that
>> extraordinary hair? ('Extraordinary' in
>> that no other mammal has anything
>> like it.)
>
> Melanin in skin: stops ultraviolet light penetration beyond the (dead)
> epidermis layer.
>
> Melanin in hair: stops infrared light (heat) penetration at the (coiled dead)
> hair layer, which reduces the temperature of the head (including brain and
> blood vessels).
>
> Homo's large brain has large heat production, sweating depends on
> evaporation, in perpetually hot humid climates sweating is more effective
> with tightly coiled but lofty hair than with damp flat hair clinging to the scalp.

Your scenario implies that sweating was
a routine everyday matter. I do not see
it that way. The hominins would have
needed a good supply of water, and that's
often hard to find. Sweating was IMO
primarily for emergencies -- such as when
they got into fights, or suffered fevers.
Those who could lose heat by sweating
survived better than those who couldn't
-- maybe their reserves had run out.

So, under my scenario, the 'tightly coiled
hair' would have had little significance
as regards sweating. It could not have
evolved for that purpose.

> Gareth Morgan:
> "In plain English, body heat is generated by mitochondria. Normal cells have
> between 2 and a couple of thousand mitochondria. Heart cells have around
> 5,000 but brain cells have an estimated two million mitochondria per cell.
> The brain is a colossally effective furnace. This is important because the heart
> is the most vulnerable organ in the human body to cold. The blood from the
> brain, which comes out much hotter than it goes in, goes directly to the heart.
> In terms of natural selection this is very much the difference between rapid
> death from hypothermic heart failure and a chilly dip."

Thanks for this. I've tried to look into it, but
it seems to be an field of active research
with relatively few answers at present.
(E.g. I'd like to know if other species brains
had the same proportion of mitochondria.)

However, in outline, it supports my argument
that large brains could have acted as a 'heat
resource' for a species where individuals
found themselves in cold water (perhaps, on
average, less than once in a lifetime) and
where the larger-brained had better chances
of survival.

Note that I'm changing my terminology from
'heat store/heat reserve' to 'heat resource'.
Those individuals who could mobilise the
sugars in their bloodstream and in various
organs (probably converting some fats) and
generate heat in their brains (held out of the
water) would be able to keep their hearts
going for longer. The larger brains would
be like having a larger engine in a vehicle.
Of course, the fuel will always run out in
the end, but this is an emergency and those
who can keep their hearts warmer more
effectively and for longer, will do better.

Elephants also have huge brains -- much
larger than is apparently fitting for their
body size. They are great swimmers --
often in estuaries and cold ocean water.
While their size provides some protection,
the cold will get to them in long-distance
swims. Their large brains may well function
in the same way as I'm proposing for
hominins.

The brains of Polar bears (498 g) are more
than double the size of those of Grizzlies
(234 g) -- probably the result of their having
to swim long distances in very cold water.
https://faculty.washington.edu/chudler/facts.html

Polar bears evolved from brown bears relatively
recenltly:

" . . Approximately 125,000 years ago a population of brown bears
in the far north of their range was likely split off from their brown
bear ancestors, perhaps because of competition for food. . . "
https://www.pbs.org/wnet/nature/arctic-bears-how-grizzlies-evolved-into-polar-bears/777/

On Monday, March 14, 2022 at 8:11:44 PM UTC-4, Paul Crowley wrote:
> On Sunday 13 March 2022 at 22:31:51 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:
>
> >> So what's the need for that extremely
> >> expensive hair? If melanated naked skin
> >> protects against UV rays, why have that
> >> extraordinary hair? ('Extraordinary' in
> >> that no other mammal has anything
> >> like it.)
> >
> > Melanin in skin: stops ultraviolet light penetration beyond the (dead)
> > epidermis layer.
> >
> > Melanin in hair: stops infrared light (heat) penetration at the (coiled dead)
> > hair layer, which reduces the temperature of the head (including brain and
> > blood vessels).
> >
> > Homo's large brain has large heat production, sweating depends on
> > evaporation, in perpetually hot humid climates sweating is more effective
> > with tightly coiled but lofty hair than with damp flat hair clinging to the scalp.
> Your scenario implies that sweating was
> a routine everyday matter.

All primates sweat. Humans sweat at 3 levels: incipiently, during sleep (hot or cold) while body is inactive, lightly while body is active but not strenuously so, and heavily while active strenuously so. Fever is our body's reaction to an attack on our metabolism, fight-or-flight is our body's reaction to a perceived attack on our body, both use sweating defensively.

I do not see
> it that way. The hominins would have
> needed a good supply of water, and that's
> often hard to find.

Like modern humans, archaic hominins lived near (but not in) shallow freshwater.

Sweating was IMO
> primarily for emergencies -- such as when
> they got into fights, or suffered fevers.

That is heavy sweating, a comparatively rare occurrence, and a poor way to cool since it excretes faster than it evaporates, unlike incipient and light sweating. Dripping sweat is both inefficient and ineffective, and leads to dehydration.

> Those who could lose heat by sweating
> survived better than those who couldn't
> -- maybe their reserves had run out.

N/A.

> So, under my scenario, the 'tightly coiled
> hair' would have had little significance
> as regards sweating. It could not have
> evolved for that purpose.

Under extreme sweating, scalp hair is irrelevant, fluid sweat pours off anyway.

> > Gareth Morgan:
> > "In plain English, body heat is generated by mitochondria. Normal cells have
> > between 2 and a couple of thousand mitochondria. Heart cells have around
> > 5,000 but brain cells have an estimated two million mitochondria per cell.
> > The brain is a colossally effective furnace. This is important because the heart
> > is the most vulnerable organ in the human body to cold. The blood from the
> > brain, which comes out much hotter than it goes in, goes directly to the heart.
> > In terms of natural selection this is very much the difference between rapid
> > death from hypothermic heart failure and a chilly dip."
> Thanks for this. I've tried to look into it, but
> it seems to be an field of active research
> with relatively few answers at present.
> (E.g. I'd like to know if other species brains
> had the same proportion of mitochondria.)
>
> However, in outline, it supports my argument
> that large brains could have acted as a 'heat
> resource' for a species where individuals
> found themselves in cold water (perhaps, on
> average, less than once in a lifetime) and
> where the larger-brained had better chances
> of survival.

N/A.

> Note that I'm changing my terminology from
> 'heat store/heat reserve' to 'heat resource'.
> Those individuals who could mobilise the
> sugars in their bloodstream and in various
> organs (probably converting some fats) and
> generate heat in their brains (held out of the
> water) would be able to keep their hearts
> going for longer. The larger brains would
> be like having a larger engine in a vehicle.
> Of course, the fuel will always run out in
> the end, but this is an emergency and those
> who can keep their hearts warmer more
> effectively and for longer, will do better.

N/A.
Unlike many taxa, humans defend themselves best when grouped defensively, and worse when not, this is shared with chimps.

> Elephants also have huge brains -- much
> larger than is apparently fitting for their
> body size. They are great swimmers --
> often in estuaries and cold ocean water.
> While their size provides some protection,
> the cold will get to them in long-distance
> swims. Their large brains may well function
> in the same way as I'm proposing for
> hominins.

N/A. Note that elephants do not eat seafood.

> The brains of Polar bears (498 g) are more
> than double the size of those of Grizzlies
> (234 g) -- probably the result of their having
> to swim long distances in very cold water.
> https://faculty.washington.edu/chudler/facts.html

Polar bears are much larger than grizzly bears, and are fully covered in fur.

> Polar bears evolved from brown bears relatively
> recenltly:
>
> " . . Approximately 125,000 years ago a population of brown bears
> in the far north of their range was likely split off from their brown
> bear ancestors, perhaps because of competition for food. . . "
> https://www.pbs.org/wnet/nature/arctic-bears-how-grizzlies-evolved-into-polar-bears/777/

On Monday, March 14, 2022 at 9:22:43 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
> On Monday, March 14, 2022 at 8:11:44 PM UTC-4, Paul Crowley wrote:
> > On Sunday 13 March 2022 at 22:31:51 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:
> >
> > >> So what's the need for that extremely
> > >> expensive hair? If melanated naked skin
> > >> protects against UV rays, why have that
> > >> extraordinary hair? ('Extraordinary' in
> > >> that no other mammal has anything
> > >> like it.)
> > >
> > > Melanin in skin: stops ultraviolet light penetration beyond the (dead)
> > > epidermis layer.
> > >
> > > Melanin in hair: stops infrared light (heat) penetration at the (coiled dead)
> > > hair layer, which reduces the temperature of the head (including brain and
> > > blood vessels).
> > >
> > > Homo's large brain has large heat production, sweating depends on
> > > evaporation, in perpetually hot humid climates sweating is more effective
> > > with tightly coiled but lofty hair than with damp flat hair clinging to the scalp.
> > Your scenario implies that sweating was
> > a routine everyday matter.
> All primates sweat. Humans sweat at 3 levels: incipiently, during sleep (hot or cold) while body is inactive, lightly while body is active but not strenuously so, and heavily while active strenuously so. Fever is our body's reaction to an attack on our metabolism, fight-or-flight is our body's reaction to a perceived attack on our body, both use sweating defensively.
> I do not see
> > it that way. The hominins would have
> > needed a good supply of water, and that's
> > often hard to find.
> Like modern humans, archaic hominins lived near (but not in) shallow freshwater.
> Sweating was IMO
> > primarily for emergencies -- such as when
> > they got into fights, or suffered fevers.
> That is heavy sweating, a comparatively rare occurrence, and a poor way to cool since it excretes faster than it evaporates, unlike incipient and light sweating. Dripping sweat is both inefficient and ineffective, and leads to dehydration.
> > Those who could lose heat by sweating
> > survived better than those who couldn't
> > -- maybe their reserves had run out.
> N/A.
> > So, under my scenario, the 'tightly coiled
> > hair' would have had little significance
> > as regards sweating. It could not have
> > evolved for that purpose.
> Under extreme sweating, scalp hair is irrelevant, fluid sweat pours off anyway.
> > > Gareth Morgan:
> > > "In plain English, body heat is generated by mitochondria. Normal cells have
> > > between 2 and a couple of thousand mitochondria. Heart cells have around
> > > 5,000 but brain cells have an estimated two million mitochondria per cell.
> > > The brain is a colossally effective furnace. This is important because the heart
> > > is the most vulnerable organ in the human body to cold. The blood from the
> > > brain, which comes out much hotter than it goes in, goes directly to the heart.
> > > In terms of natural selection this is very much the difference between rapid
> > > death from hypothermic heart failure and a chilly dip."
> > Thanks for this. I've tried to look into it, but
> > it seems to be an field of active research
> > with relatively few answers at present.
> > (E.g. I'd like to know if other species brains
> > had the same proportion of mitochondria.)
> >
> > However, in outline, it supports my argument
> > that large brains could have acted as a 'heat
> > resource' for a species where individuals
> > found themselves in cold water (perhaps, on
> > average, less than once in a lifetime) and
> > where the larger-brained had better chances
> > of survival.
> N/A.
> > Note that I'm changing my terminology from
> > 'heat store/heat reserve' to 'heat resource'.
> > Those individuals who could mobilise the
> > sugars in their bloodstream and in various
> > organs (probably converting some fats) and
> > generate heat in their brains (held out of the
> > water) would be able to keep their hearts
> > going for longer. The larger brains would
> > be like having a larger engine in a vehicle.
> > Of course, the fuel will always run out in
> > the end, but this is an emergency and those
> > who can keep their hearts warmer more
> > effectively and for longer, will do better.
> N/A.
> Unlike many taxa, humans defend themselves best when grouped defensively, and worse when not, this is shared with chimps.
> > Elephants also have huge brains -- much
> > larger than is apparently fitting for their
> > body size. They are great swimmers --
> > often in estuaries and cold ocean water.
> > While their size provides some protection,
> > the cold will get to them in long-distance
> > swims. Their large brains may well function
> > in the same way as I'm proposing for
> > hominins.
> N/A. Note that elephants do not eat seafood.
> > The brains of Polar bears (498 g) are more
> > than double the size of those of Grizzlies
> > (234 g) -- probably the result of their having
> > to swim long distances in very cold water.
> > https://faculty.washington.edu/chudler/facts.html
> Polar bears are much larger than grizzly bears, and are fully covered in fur.
> > Polar bears evolved from brown bears relatively
> > recenltly:
> >
> > " . . Approximately 125,000 years ago a population of brown bears
> > in the far north of their range was likely split off from their brown
> > bear ancestors, perhaps because of competition for food. . . "
> > https://www.pbs.org/wnet/nature/arctic-bears-how-grizzlies-evolved-into-polar-bears/777/

On bears:

Male polar bears are twice the weight of male grizzly bears.

Short faced bears are extinct except the Andes SPECTACLED BEAR, which is the only South American bear, and is the world’s last short-faced bear, and which builds tree nests.

The name “spectacled” comes from the lighter markings around their eyes that look like glasses.

📍Location: The spectacled bear is the world’s last short-faced bear and the only bear native to South America. This vulnerable species of 13,000 to 18,000 remaining bears are found in the cloud forests of the Andes from Argentina to Ecuador.

📏 Size: They are mid-sized, weighing 175 to 275 pounds, and standing 47 to 79 inches tall.

👀 Features: The name “spectacled” comes from the lighter markings around their eyes that sometimes look like glasses. They spend most of their time in trees where they build nest platforms, sleep and jealously guard precious fruit and carcasses.

🌱 Diet: Spectacled bears are mostly herbivores with a diet consisting of mostly cactus, bromeliad, palm hearts, and fruit, but they will opportunistically eat mammals like rabbits and tapirs.

😱 Dangerous? Living in remote mountains, these shy bears may be the least dangerous of all bear species.

On Monday, March 14, 2022 at 9:22:43 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
> On Monday, March 14, 2022 at 8:11:44 PM UTC-4, Paul Crowley wrote:
> > On Sunday 13 March 2022 at 22:31:51 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:
> >
> > >> So what's the need for that extremely
> > >> expensive hair? If melanated naked skin
> > >> protects against UV rays, why have that
> > >> extraordinary hair? ('Extraordinary' in
> > >> that no other mammal has anything
> > >> like it.)
> > >
> > > Melanin in skin: stops ultraviolet light penetration beyond the (dead)
> > > epidermis layer.
> > >
> > > Melanin in hair: stops infrared light (heat) penetration at the (coiled dead)
> > > hair layer, which reduces the temperature of the head (including brain and
> > > blood vessels).
> > >
> > > Homo's large brain has large heat production, sweating depends on
> > > evaporation, in perpetually hot humid climates sweating is more effective
> > > with tightly coiled but lofty hair than with damp flat hair clinging to the scalp.
> > Your scenario implies that sweating was
> > a routine everyday matter.
> All primates sweat. Humans sweat at 3 levels: incipiently, during sleep (hot or cold) while body is inactive, lightly while body is active but not strenuously so, and heavily while active strenuously so. Fever is our body's reaction to an attack on our metabolism, fight-or-flight is our body's reaction to a perceived attack on our body, both use sweating defensively.
> I do not see
> > it that way. The hominins would have
> > needed a good supply of water, and that's
> > often hard to find.
> Like modern humans, archaic hominins lived near (but not in) shallow freshwater.
> Sweating was IMO
> > primarily for emergencies -- such as when
> > they got into fights, or suffered fevers.
> That is heavy sweating, a comparatively rare occurrence, and a poor way to cool since it excretes faster than it evaporates, unlike incipient and light sweating. Dripping sweat is both inefficient and ineffective, and leads to dehydration.
> > Those who could lose heat by sweating
> > survived better than those who couldn't
> > -- maybe their reserves had run out.
> N/A.
> > So, under my scenario, the 'tightly coiled
> > hair' would have had little significance
> > as regards sweating. It could not have
> > evolved for that purpose.
> Under extreme sweating, scalp hair is irrelevant, fluid sweat pours off anyway.
> > > Gareth Morgan:
> > > "In plain English, body heat is generated by mitochondria. Normal cells have
> > > between 2 and a couple of thousand mitochondria. Heart cells have around
> > > 5,000 but brain cells have an estimated two million mitochondria per cell.
> > > The brain is a colossally effective furnace. This is important because the heart
> > > is the most vulnerable organ in the human body to cold. The blood from the
> > > brain, which comes out much hotter than it goes in, goes directly to the heart.
> > > In terms of natural selection this is very much the difference between rapid
> > > death from hypothermic heart failure and a chilly dip."
> > Thanks for this. I've tried to look into it, but
> > it seems to be an field of active research
> > with relatively few answers at present.
> > (E.g. I'd like to know if other species brains
> > had the same proportion of mitochondria.)
> >
> > However, in outline, it supports my argument
> > that large brains could have acted as a 'heat
> > resource' for a species where individuals
> > found themselves in cold water (perhaps, on
> > average, less than once in a lifetime) and
> > where the larger-brained had better chances
> > of survival.
> N/A.
> > Note that I'm changing my terminology from
> > 'heat store/heat reserve' to 'heat resource'.
> > Those individuals who could mobilise the
> > sugars in their bloodstream and in various
> > organs (probably converting some fats) and
> > generate heat in their brains (held out of the
> > water) would be able to keep their hearts
> > going for longer. The larger brains would
> > be like having a larger engine in a vehicle.
> > Of course, the fuel will always run out in
> > the end, but this is an emergency and those
> > who can keep their hearts warmer more
> > effectively and for longer, will do better.
> N/A.
> Unlike many taxa, humans defend themselves best when grouped defensively, and worse when not, this is shared with chimps.
> > Elephants also have huge brains -- much
> > larger than is apparently fitting for their
> > body size. They are great swimmers --
> > often in estuaries and cold ocean water.
> > While their size provides some protection,
> > the cold will get to them in long-distance
> > swims. Their large brains may well function
> > in the same way as I'm proposing for
> > hominins.
> N/A. Note that elephants do not eat seafood.
> > The brains of Polar bears (498 g) are more
> > than double the size of those of Grizzlies
> > (234 g) -- probably the result of their having
> > to swim long distances in very cold water.
> > https://faculty.washington.edu/chudler/facts.html
> Polar bears are much larger than grizzly bears, and are fully covered in fur.
> > Polar bears evolved from brown bears relatively
> > recenltly:
> >
> > " . . Approximately 125,000 years ago a population of brown bears
> > in the far north of their range was likely split off from their brown
> > bear ancestors, perhaps because of competition for food. . . "
> > https://www.pbs.org/wnet/nature/arctic-bears-how-grizzlies-evolved-into-polar-bears/777/

Warm blooded fauna increased specialized neuron density
https://archaeologynewsnetwork.blogspot.com/2022/03/neuron-counts-reveal-brain-complexity.html?m=1
See graph.

Mitochondria aren't mentioned but obviously are key to faster better cognition processing. Overheating must be avoided, thus the advantage of coil-hair scalp/brain covering lofted above melanin-rich skin in tropical climes, as well as shelters.

On Thursday, March 10, 2022 at 9:42:56 AM UTC-5, DD'eDeN aka note/nickname/alas_my_loves wrote:
> One of the few valuable papers Lasisi found is a 1973 study in the American Journal of Physical Anthropology. In it, Daniel Hrdy, of Harvard University, loosely described a methodology to quantify the shape of a hair curl, which he applied to seven groups of people around the world. Imperfect as it was, it was the starting point Lasisi was looking for. She built off his research, honing a methodology for fitting hair fibers to a circle to determine curvature and publishing her results in the American Journal of Biological Anthropology and Nature’s Scientific Reports.
>
> Jablonski says Lasisi’s work suggests how, just as melanated skin protects against UV rays, tightly curled hairs also protect humans from the sun. Tight curls create lofted, airy ventilation structures for the head, allowing it to breathe [sweat] while providing extra protection from solar radiation. That was important for our newly bipedal human ancestors, she says, and you can’t do that with flat hair.
>
> Read more about misconceptions in racial classification: “Race Is Real, But It’s Not Genetic”
>
> Sapiens.org
-

https://archaeologynewsnetwork.blogspot.com/2022/03/new-study-sheds-light-on-early-human.html

Specifically, the researchers aimed to assess the impacts of climate, body size and color vision on hair evolution.

The researchers found:

- Sifaka lemurs, which are native to Madagascar, have denser hair in dry, open environments. The researchers believe that, like early humans, the lemurs' hair helps protect against the strong rays of the sun.

- Lemurs in colder regions are more likely to have dark hair. This is the first evidence in mammals for a classic pattern in nature called Bogert's Rule, which states that dark colors could aid with thermoregulation as they help absorb heat from the sun's rays.

- Red hair in lemurs is associated with enhanced color vision. According to the researchers, populations that can see a larger range of colors are more likely to have patches of red hair.

- Multiple evolutionary pressures may act on one trait and the strength of their influence may vary between species.

"Human hair evolution remains a mystery, largely because hair does not fossilize," Elizabeth Tapanes, lead author on the paper and a postdoctoral scholar at the University of San Diego, California, said. (Tapanes conducted the study while a doctoral student at GW.) "The lemurs we studied exhibit an upright posture like humans and live in a variety of ecosystems like early humans, so our results provide a unique window into human hair evolution."

https://onlinelibrary.wiley.com/doi/10.1002/ajpa.24508

On Tuesday, March 15, 2022 at 2:55:01 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
> On Monday, March 14, 2022 at 9:22:43 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
> > On Monday, March 14, 2022 at 8:11:44 PM UTC-4, Paul Crowley wrote:
> > > On Sunday 13 March 2022 at 22:31:51 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:
> > >
> > > >> So what's the need for that extremely
> > > >> expensive hair? If melanated naked skin
> > > >> protects against UV rays, why have that
> > > >> extraordinary hair? ('Extraordinary' in
> > > >> that no other mammal has anything
> > > >> like it.)
> > > >
> > > > Melanin in skin: stops ultraviolet light penetration beyond the (dead)
> > > > epidermis layer.
> > > >
> > > > Melanin in hair: stops infrared light (heat) penetration at the (coiled dead)
> > > > hair layer, which reduces the temperature of the head (including brain and
> > > > blood vessels).
> > > >
> > > > Homo's large brain has large heat production, sweating depends on
> > > > evaporation, in perpetually hot humid climates sweating is more effective
> > > > with tightly coiled but lofty hair than with damp flat hair clinging to the scalp.
> > > Your scenario implies that sweating was
> > > a routine everyday matter.
> > All primates sweat. Humans sweat at 3 levels: incipiently, during sleep (hot or cold) while body is inactive, lightly while body is active but not strenuously so, and heavily while active strenuously so. Fever is our body's reaction to an attack on our metabolism, fight-or-flight is our body's reaction to a perceived attack on our body, both use sweating defensively.
> > I do not see
> > > it that way. The hominins would have
> > > needed a good supply of water, and that's
> > > often hard to find.
> > Like modern humans, archaic hominins lived near (but not in) shallow freshwater.
> > Sweating was IMO
> > > primarily for emergencies -- such as when
> > > they got into fights, or suffered fevers.
> > That is heavy sweating, a comparatively rare occurrence, and a poor way to cool since it excretes faster than it evaporates, unlike incipient and light sweating. Dripping sweat is both inefficient and ineffective, and leads to dehydration.
> > > Those who could lose heat by sweating
> > > survived better than those who couldn't
> > > -- maybe their reserves had run out.
> > N/A.
> > > So, under my scenario, the 'tightly coiled
> > > hair' would have had little significance
> > > as regards sweating. It could not have
> > > evolved for that purpose.
> > Under extreme sweating, scalp hair is irrelevant, fluid sweat pours off anyway.
> > > > Gareth Morgan:
> > > > "In plain English, body heat is generated by mitochondria. Normal cells have
> > > > between 2 and a couple of thousand mitochondria. Heart cells have around
> > > > 5,000 but brain cells have an estimated two million mitochondria per cell.
> > > > The brain is a colossally effective furnace. This is important because the heart
> > > > is the most vulnerable organ in the human body to cold. The blood from the
> > > > brain, which comes out much hotter than it goes in, goes directly to the heart.
> > > > In terms of natural selection this is very much the difference between rapid
> > > > death from hypothermic heart failure and a chilly dip."
> > > Thanks for this. I've tried to look into it, but
> > > it seems to be an field of active research
> > > with relatively few answers at present.
> > > (E.g. I'd like to know if other species brains
> > > had the same proportion of mitochondria.)
> > >
> > > However, in outline, it supports my argument
> > > that large brains could have acted as a 'heat
> > > resource' for a species where individuals
> > > found themselves in cold water (perhaps, on
> > > average, less than once in a lifetime) and
> > > where the larger-brained had better chances
> > > of survival.
> > N/A.
> > > Note that I'm changing my terminology from
> > > 'heat store/heat reserve' to 'heat resource'.
> > > Those individuals who could mobilise the
> > > sugars in their bloodstream and in various
> > > organs (probably converting some fats) and
> > > generate heat in their brains (held out of the
> > > water) would be able to keep their hearts
> > > going for longer. The larger brains would
> > > be like having a larger engine in a vehicle.
> > > Of course, the fuel will always run out in
> > > the end, but this is an emergency and those
> > > who can keep their hearts warmer more
> > > effectively and for longer, will do better.
> > N/A.
> > Unlike many taxa, humans defend themselves best when grouped defensively, and worse when not, this is shared with chimps.
> > > Elephants also have huge brains -- much
> > > larger than is apparently fitting for their
> > > body size. They are great swimmers --
> > > often in estuaries and cold ocean water.
> > > While their size provides some protection,
> > > the cold will get to them in long-distance
> > > swims. Their large brains may well function
> > > in the same way as I'm proposing for
> > > hominins.
> > N/A. Note that elephants do not eat seafood.
> > > The brains of Polar bears (498 g) are more
> > > than double the size of those of Grizzlies
> > > (234 g) -- probably the result of their having
> > > to swim long distances in very cold water.
> > > https://faculty.washington.edu/chudler/facts.html
> > Polar bears are much larger than grizzly bears, and are fully covered in fur.
> > > Polar bears evolved from brown bears relatively
> > > recenltly:
> > >
> > > " . . Approximately 125,000 years ago a population of brown bears
> > > in the far north of their range was likely split off from their brown
> > > bear ancestors, perhaps because of competition for food. . . "
> > > https://www.pbs.org/wnet/nature/arctic-bears-how-grizzlies-evolved-into-polar-bears/777/
> Warm blooded fauna increased specialized neuron density
> https://archaeologynewsnetwork.blogspot.com/2022/03/neuron-counts-reveal-brain-complexity.html?m=1
> See graph.
>
> Mitochondria aren't mentioned but obviously are key to faster better cognition processing. Overheating must be avoided, thus the advantage of coil-hair scalp/brain covering lofted above melanin-rich skin in tropical climes, as well as shelters.
- Mitochondria
Jean Gibbons at Quora:

How do you move energy through your body?

ATP is formed at the mitochondria and functions as the “energy currency” within the body. Energy is found “stored” in the bonding of a third phosphate group to the molecule. Energy is contained within each and every bond, but the energy in the bonding of the third phosphate is available in a controlled fashion. ATP = Adenine TriPhosphate molecule

The products of digestion: amino acids, glucose, fats, etc. all contain potential energy. As these chemicals are metabolized, the energy contained within is captured within a molecule of ATP.

As the blood flows throughout the body, the energy is made available throughout as well

On Friday, March 25, 2022 at 12:02:35 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
> On Tuesday, March 15, 2022 at 2:55:01 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
> > On Monday, March 14, 2022 at 9:22:43 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
> > > On Monday, March 14, 2022 at 8:11:44 PM UTC-4, Paul Crowley wrote:
> > > > On Sunday 13 March 2022 at 22:31:51 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:
> > > >
> > > > >> So what's the need for that extremely
> > > > >> expensive hair? If melanated naked skin
> > > > >> protects against UV rays, why have that
> > > > >> extraordinary hair? ('Extraordinary' in
> > > > >> that no other mammal has anything
> > > > >> like it.)
> > > > >
> > > > > Melanin in skin: stops ultraviolet light penetration beyond the (dead)
> > > > > epidermis layer.
> > > > >
> > > > > Melanin in hair: stops infrared light (heat) penetration at the (coiled dead)
> > > > > hair layer, which reduces the temperature of the head (including brain and
> > > > > blood vessels).
> > > > >
> > > > > Homo's large brain has large heat production, sweating depends on
> > > > > evaporation, in perpetually hot humid climates sweating is more effective
> > > > > with tightly coiled but lofty hair than with damp flat hair clinging to the scalp.
> > > > Your scenario implies that sweating was
> > > > a routine everyday matter.
> > > All primates sweat. Humans sweat at 3 levels: incipiently, during sleep (hot or cold) while body is inactive, lightly while body is active but not strenuously so, and heavily while active strenuously so. Fever is our body's reaction to an attack on our metabolism, fight-or-flight is our body's reaction to a perceived attack on our body, both use sweating defensively.
> > > I do not see
> > > > it that way. The hominins would have
> > > > needed a good supply of water, and that's
> > > > often hard to find.
> > > Like modern humans, archaic hominins lived near (but not in) shallow freshwater.
> > > Sweating was IMO
> > > > primarily for emergencies -- such as when
> > > > they got into fights, or suffered fevers.
> > > That is heavy sweating, a comparatively rare occurrence, and a poor way to cool since it excretes faster than it evaporates, unlike incipient and light sweating. Dripping sweat is both inefficient and ineffective, and leads to dehydration.
> > > > Those who could lose heat by sweating
> > > > survived better than those who couldn't
> > > > -- maybe their reserves had run out.
> > > N/A.
> > > > So, under my scenario, the 'tightly coiled
> > > > hair' would have had little significance
> > > > as regards sweating. It could not have
> > > > evolved for that purpose.
> > > Under extreme sweating, scalp hair is irrelevant, fluid sweat pours off anyway.
> > > > > Gareth Morgan:
> > > > > "In plain English, body heat is generated by mitochondria. Normal cells have
> > > > > between 2 and a couple of thousand mitochondria. Heart cells have around
> > > > > 5,000 but brain cells have an estimated two million mitochondria per cell.
> > > > > The brain is a colossally effective furnace. This is important because the heart
> > > > > is the most vulnerable organ in the human body to cold. The blood from the
> > > > > brain, which comes out much hotter than it goes in, goes directly to the heart.
> > > > > In terms of natural selection this is very much the difference between rapid
> > > > > death from hypothermic heart failure and a chilly dip."
> > > > Thanks for this. I've tried to look into it, but
> > > > it seems to be an field of active research
> > > > with relatively few answers at present.
> > > > (E.g. I'd like to know if other species brains
> > > > had the same proportion of mitochondria.)
> > > >
> > > > However, in outline, it supports my argument
> > > > that large brains could have acted as a 'heat
> > > > resource' for a species where individuals
> > > > found themselves in cold water (perhaps, on
> > > > average, less than once in a lifetime) and
> > > > where the larger-brained had better chances
> > > > of survival.
> > > N/A.
> > > > Note that I'm changing my terminology from
> > > > 'heat store/heat reserve' to 'heat resource'.
> > > > Those individuals who could mobilise the
> > > > sugars in their bloodstream and in various
> > > > organs (probably converting some fats) and
> > > > generate heat in their brains (held out of the
> > > > water) would be able to keep their hearts
> > > > going for longer. The larger brains would
> > > > be like having a larger engine in a vehicle.
> > > > Of course, the fuel will always run out in
> > > > the end, but this is an emergency and those
> > > > who can keep their hearts warmer more
> > > > effectively and for longer, will do better.
> > > N/A.
> > > Unlike many taxa, humans defend themselves best when grouped defensively, and worse when not, this is shared with chimps.
> > > > Elephants also have huge brains -- much
> > > > larger than is apparently fitting for their
> > > > body size. They are great swimmers --
> > > > often in estuaries and cold ocean water.
> > > > While their size provides some protection,
> > > > the cold will get to them in long-distance
> > > > swims. Their large brains may well function
> > > > in the same way as I'm proposing for
> > > > hominins.
> > > N/A. Note that elephants do not eat seafood.
> > > > The brains of Polar bears (498 g) are more
> > > > than double the size of those of Grizzlies
> > > > (234 g) -- probably the result of their having
> > > > to swim long distances in very cold water.
> > > > https://faculty.washington.edu/chudler/facts.html
> > > Polar bears are much larger than grizzly bears, and are fully covered in fur.
> > > > Polar bears evolved from brown bears relatively
> > > > recenltly:
> > > >
> > > > " . . Approximately 125,000 years ago a population of brown bears
> > > > in the far north of their range was likely split off from their brown
> > > > bear ancestors, perhaps because of competition for food. . . "
> > > > https://www.pbs.org/wnet/nature/arctic-bears-how-grizzlies-evolved-into-polar-bears/777/
> > Warm blooded fauna increased specialized neuron density
> > https://archaeologynewsnetwork.blogspot.com/2022/03/neuron-counts-reveal-brain-complexity.html?m=1
> > See graph.
> >
> > Mitochondria aren't mentioned but obviously are key to faster better cognition processing. Overheating must be avoided, thus the advantage of coil-hair scalp/brain covering lofted above melanin-rich skin in tropical climes, as well as shelters.
> -
> Mitochondria
> Jean Gibbons at Quora:
>
> How do you move energy through your body?
>
> ATP is formed at the mitochondria and functions as the “energy currency” within the body. Energy is found “stored” in the bonding of a third phosphate group to the molecule. Energy is contained within each and every bond, but the energy in the bonding of the third phosphate is available in a controlled fashion. ATP = Adenine TriPhosphate molecule
>
> The products of digestion: amino acids, glucose, fats, etc. all contain potential energy. As these chemicals are metabolized, the energy contained within is captured within a molecule of ATP.
>
> As the blood flows throughout the body, the energy is made available throughout as well

https://www.sciencedaily.com/releases/2004/01/040114075853.htm

On Friday, March 25, 2022 at 12:16:53 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
> On Friday, March 25, 2022 at 12:02:35 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
> > On Tuesday, March 15, 2022 at 2:55:01 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
> > > On Monday, March 14, 2022 at 9:22:43 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
> > > > On Monday, March 14, 2022 at 8:11:44 PM UTC-4, Paul Crowley wrote:
> > > > > On Sunday 13 March 2022 at 22:31:51 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:
> > > > >
> > > > > >> So what's the need for that extremely
> > > > > >> expensive hair? If melanated naked skin
> > > > > >> protects against UV rays, why have that
> > > > > >> extraordinary hair? ('Extraordinary' in
> > > > > >> that no other mammal has anything
> > > > > >> like it.)
> > > > > >
> > > > > > Melanin in skin: stops ultraviolet light penetration beyond the (dead)
> > > > > > epidermis layer.
> > > > > >
> > > > > > Melanin in hair: stops infrared light (heat) penetration at the (coiled dead)
> > > > > > hair layer, which reduces the temperature of the head (including brain and
> > > > > > blood vessels).
> > > > > >
> > > > > > Homo's large brain has large heat production, sweating depends on
> > > > > > evaporation, in perpetually hot humid climates sweating is more effective
> > > > > > with tightly coiled but lofty hair than with damp flat hair clinging to the scalp.
> > > > > Your scenario implies that sweating was
> > > > > a routine everyday matter.
> > > > All primates sweat. Humans sweat at 3 levels: incipiently, during sleep (hot or cold) while body is inactive, lightly while body is active but not strenuously so, and heavily while active strenuously so. Fever is our body's reaction to an attack on our metabolism, fight-or-flight is our body's reaction to a perceived attack on our body, both use sweating defensively.
> > > > I do not see
> > > > > it that way. The hominins would have
> > > > > needed a good supply of water, and that's
> > > > > often hard to find.
> > > > Like modern humans, archaic hominins lived near (but not in) shallow freshwater.
> > > > Sweating was IMO
> > > > > primarily for emergencies -- such as when
> > > > > they got into fights, or suffered fevers.
> > > > That is heavy sweating, a comparatively rare occurrence, and a poor way to cool since it excretes faster than it evaporates, unlike incipient and light sweating. Dripping sweat is both inefficient and ineffective, and leads to dehydration.
> > > > > Those who could lose heat by sweating
> > > > > survived better than those who couldn't
> > > > > -- maybe their reserves had run out.
> > > > N/A.
> > > > > So, under my scenario, the 'tightly coiled
> > > > > hair' would have had little significance
> > > > > as regards sweating. It could not have
> > > > > evolved for that purpose.
> > > > Under extreme sweating, scalp hair is irrelevant, fluid sweat pours off anyway.
> > > > > > Gareth Morgan:
> > > > > > "In plain English, body heat is generated by mitochondria. Normal cells have
> > > > > > between 2 and a couple of thousand mitochondria. Heart cells have around
> > > > > > 5,000 but brain cells have an estimated two million mitochondria per cell.
> > > > > > The brain is a colossally effective furnace. This is important because the heart
> > > > > > is the most vulnerable organ in the human body to cold. The blood from the
> > > > > > brain, which comes out much hotter than it goes in, goes directly to the heart.
> > > > > > In terms of natural selection this is very much the difference between rapid
> > > > > > death from hypothermic heart failure and a chilly dip."
> > > > > Thanks for this. I've tried to look into it, but
> > > > > it seems to be an field of active research
> > > > > with relatively few answers at present.
> > > > > (E.g. I'd like to know if other species brains
> > > > > had the same proportion of mitochondria.)
> > > > >
> > > > > However, in outline, it supports my argument
> > > > > that large brains could have acted as a 'heat
> > > > > resource' for a species where individuals
> > > > > found themselves in cold water (perhaps, on
> > > > > average, less than once in a lifetime) and
> > > > > where the larger-brained had better chances
> > > > > of survival.
> > > > N/A.
> > > > > Note that I'm changing my terminology from
> > > > > 'heat store/heat reserve' to 'heat resource'.
> > > > > Those individuals who could mobilise the
> > > > > sugars in their bloodstream and in various
> > > > > organs (probably converting some fats) and
> > > > > generate heat in their brains (held out of the
> > > > > water) would be able to keep their hearts
> > > > > going for longer. The larger brains would
> > > > > be like having a larger engine in a vehicle.
> > > > > Of course, the fuel will always run out in
> > > > > the end, but this is an emergency and those
> > > > > who can keep their hearts warmer more
> > > > > effectively and for longer, will do better.
> > > > N/A.
> > > > Unlike many taxa, humans defend themselves best when grouped defensively, and worse when not, this is shared with chimps.
> > > > > Elephants also have huge brains -- much
> > > > > larger than is apparently fitting for their
> > > > > body size. They are great swimmers --
> > > > > often in estuaries and cold ocean water.
> > > > > While their size provides some protection,
> > > > > the cold will get to them in long-distance
> > > > > swims. Their large brains may well function
> > > > > in the same way as I'm proposing for
> > > > > hominins.
> > > > N/A. Note that elephants do not eat seafood.
> > > > > The brains of Polar bears (498 g) are more
> > > > > than double the size of those of Grizzlies
> > > > > (234 g) -- probably the result of their having
> > > > > to swim long distances in very cold water.
> > > > > https://faculty.washington.edu/chudler/facts.html
> > > > Polar bears are much larger than grizzly bears, and are fully covered in fur.
> > > > > Polar bears evolved from brown bears relatively
> > > > > recenltly:
> > > > >
> > > > > " . . Approximately 125,000 years ago a population of brown bears
> > > > > in the far north of their range was likely split off from their brown
> > > > > bear ancestors, perhaps because of competition for food. . . "
> > > > > https://www.pbs.org/wnet/nature/arctic-bears-how-grizzlies-evolved-into-polar-bears/777/
> > > Warm blooded fauna increased specialized neuron density
> > > https://archaeologynewsnetwork.blogspot.com/2022/03/neuron-counts-reveal-brain-complexity.html?m=1
> > > See graph.
> > >
> > > Mitochondria aren't mentioned but obviously are key to faster better cognition processing. Overheating must be avoided, thus the advantage of coil-hair scalp/brain covering lofted above melanin-rich skin in tropical climes, as well as shelters.
> > -
> > Mitochondria
> > Jean Gibbons at Quora:
> >
> > How do you move energy through your body?
> >
> > ATP is formed at the mitochondria and functions as the “energy currency” within the body. Energy is found “stored” in the bonding of a third phosphate group to the molecule. Energy is contained within each and every bond, but the energy in the bonding of the third phosphate is available in a controlled fashion. ATP = Adenine TriPhosphate molecule
> >
> > The products of digestion: amino acids, glucose, fats, etc. all contain potential energy. As these chemicals are metabolized, the energy contained within is captured within a molecule of ATP.
> >
> > As the blood flows throughout the body, the energy is made available throughout as well
> https://www.sciencedaily.com/releases/2004/01/040114075853.htm

On Thursday 10 March 2022 at 14:42:56 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:

> Tight curls create lofted, airy ventilation structures for the head,
> allowing it to breathe [sweat] while providing extra protection
> from solar radiation. That was important for our newly bipedal
> human ancestors, she says, and you can t do that with flat hair.

I've just heard a short radio interview with Simon
Wooley.

https://en.wikipedia.org/wiki/Simon_Woolley,_Baron_Woolley_of_Woodford

Today programme 16/04/2022 at 1:43:25
https://www.bbc.co.uk/sounds/play/m0016gvm

He and his brother were adopted by a white
couple who had no idea how to cut or trim
their (Afro) hair. Eventually they found barbers
who knew what to do.

Take a look at some videos of barbers working
on Afro hair. This is one:
https://www.youtube.com/watch?v=qv4R09k9EN8

The sheer quantity of natural uncut Afro
hair -- which is what our ancestors evolved
to possess -- is staggering. It certainly did
not allow for easy sweating. In fact, we can
say that, with such hair, no level of sweating
would produce the slightest cooling effect on
the scalp.

> Tight curls create lofted, airy ventilation structures for the head,
> allowing it to breathe [sweat] while providing extra protection
> from solar radiation. That was important for our newly bipedal
> human ancestors, she says, and you can t do that with flat hair.

Given that the rest of the body was naked,
it also makes no sense to claim that such
dense hair was there to protect scalp skin
from UV rays from the sun.

So what was it for?

Op donderdag 10 maart 2022 om 15:42:56 UTC+1 schreef DD'eDeN aka note/nickname/alas_my_loves:

> Lasisi 1973 Am.J.phys.Anthrop.: Daniel Hrdy loosely described a methodology to quantify the shape of a hair curl, which he applied to 7 groups of people around the world: the starting point Lasisi was looking for.
She built off his research, honing a methodology for fitting hair fibers to a circle to determine curvature (Am.J.biol.Anthrop., Scient.Rep.).
Jablonski says Lasisi’s work suggests how (melanated skin protects against UV) tightly curled hairs also protect humans from the sun.
Tight curls create lofted, airy ventilation structures for the head, allowing it to breathe [sweat] while providing extra protection from solar radiation.
That was important for our newly bipedal human ancestors, she says, and you can’t do that with flat hair.

Possibly correct for H.sapiens, but not for earlier Homo: google "coastal dispersal Pleistocene Homo PPT" + illustrations.

On Thursday, March 10, 2022 at 3:07:28 PM UTC-5, Paul Crowley wrote:
> On Thursday 10 March 2022 at 14:42:56 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:
>
> > Jablonski says Lasisi’s work suggests how, just as melanated skin
> > protects against UV rays, tightly curled hairs also protect humans
> > from the sun.
> So what's the need for that extremely
> expensive hair?

All mammals have hair, so not particularly expensive.
Already answered.

If melanated naked skin
> protects against UV rays, why have that
> extraordinary hair? ('Extraordinary' in
> that no other mammal has anything
> like it.)
> > Tight curls create lofted, airy ventilation structures for the head,
> > allowing it to breathe [sweat] while providing extra protection
> > from solar radiation. That was important for our newly bipedal
> > human ancestors, she says, and you can t do that with flat hair.

Note: "Flat hair" here refers to scalp hair (Asian) that lies flat on the scalp, but whose strands are actually circular in cross-section; while coiled hair (Afro) cannot lie flat on the scalp (unless forced by a hat) but whose strands are flat in cross-section, caucasian hair is midway between them..

> Can't do what . . exactly? There's no
> problem with sweating elsewhere on
> the body.
>
> What's the need for that dense, tightly-
> curled hair?
>
> Don't pretend you have an answer
> when all you can present is verbiage.
> That's deceptive politics, not science.

On Saturday, April 16, 2022 at 9:38:13 AM UTC-4, Paul Crowley wrote:
> On Thursday 10 March 2022 at 14:42:56 UTC, DD'eDeN aka note/nickname/alas_my_loves wrote:
>
> > Tight curls create lofted, airy ventilation structures for the head,
> > allowing it to breathe [sweat] while providing extra protection
> > from solar radiation. That was important for our newly bipedal
> > human ancestors, she says, and you can t do that with flat hair.
> I've just heard a short radio interview with Simon
> Wooley.
>
> https://en.wikipedia.org/wiki/Simon_Woolley,_Baron_Woolley_of_Woodford
>
> Today programme 16/04/2022 at 1:43:25
> https://www.bbc.co.uk/sounds/play/m0016gvm
>
> He and his brother were adopted by a white
> couple who had no idea how to cut or trim
> their (Afro) hair. Eventually they found barbers
> who knew what to do.
>
> Take a look at some videos of barbers working
> on Afro hair. This is one:
> https://www.youtube.com/watch?v=qv4R09k9EN8

The man appears to have mixed black and white bio heritage, akin to Melanesian, Mulatto, Semitic etc. hair, not as tightly coiled as modern Sub-Saharan people's hair.

> The sheer quantity of natural uncut Afro
> hair -- which is what our ancestors evolved
> to possess -- is staggering.

Our (Euro-caucasian) ancestors did not have tightly coiled hair, but probably wavy coarse hair, closer to chimp hair. Neanderthals and Denisovans probably had straighter hair.
Tightly-coiled Afro hair is probably related to tropical terrestrial proto-agriculture/herding in more open environments where direct sun was a selective force, than in the ancestral forest environment. Rainforestpygmies and Kalahari bushmen have coiled hair, but in tufts rather than continuous pelage that the Bantu people have.

It certainly did
> not allow for easy sweating. In fact, we can
> say that, with such hair, no level of sweating
> would produce the slightest cooling effect on
> the scalp.

That is obviously false. Blondes with wavy hair have many more strands per scalp than Blacks with tightly coiled hair. Coils block UV while allowing airflow along the scalp, straight hair blocks much less UV, unless shorn, good in temperate and polar climates.

> > Tight curls create lofted, airy ventilation structures for the head,
> > allowing it to breathe [sweat] while providing extra protection
> > from solar radiation. That was important for our newly bipedal
> > human ancestors, she says, and you can t do that with flat hair.
> Given that the rest of the body was naked,

Black people have tightly coiled body hair, so tight-coiling preceded body hair reduction.

> it also makes no sense to claim that such
> dense hair

Tightly-coiled Afro hair is not "dense" hair.

was there to protect scalp skin
> from UV rays from the sun.

It protects against tropical-year-round sun UV.

>
> So what was it for?
So??

On Saturday 16 April 2022 at 19:32:11 UTC+1, DD'eDeN aka note/nickname/alas_my_loves wrote:

> Black people have tightly coiled body hair, so tight-coiling preceded body hair reduction.
.. .
When and why do you see "body hair
reduction'?
.. .
>> it also makes no sense to claim that such
>> dense hair
>. .
> Tightly-coiled Afro hair is not "dense" hair.
.. .
Please find an image of natural fully-grown
'tightly-coiled Afro hair'. I can't. I suspect
that you won't be able to either. In other
words, you're imagining something that
does not exist.
.. .
> It protects against tropical-year-round sun UV.
.. .
Why does the scalp need that protection
when the rest of the body doesn't?
.. .

On Sunday, April 17, 2022 at 7:51:00 AM UTC-4, Paul Crowley wrote:
> On Saturday 16 April 2022 at 19:32:11 UTC+1, DD'eDeN aka note/nickname/alas_my_loves wrote:
>
> > Black people have tightly coiled body hair, so tight-coiling preceded body hair reduction.

Amend: the curling of body hair began before Hs body hair greatly reduced, but at a very slow rate of change until proto-agriculture, and both are still under selection. Body hair/fur reduction first began with the change from fully exposed arboreal branch/tree-fork sleeping (OWM, gibbons) to partly exposed arboreal bowl nesting (great apes) and increased in the change from arboreal bowl nesting to non-exposed terrestrial dome dwelling (Homo) while under forest canopy. Note that body hair reduction (and concomitant scalp hair lengthening) was mainly a nocturnal/inactivity selection trait, mostly connected to prone/supine posture relative to enclosure; while body & scalp hair curling was mainly a diurnal/activity selection trait mostly connected to upright orthograde posture relative to exposure to sunlight and convective air currents. A parallel condition today is in mature people, hair loss is independent of hair graying but both can occur simultaneously or sequentially, a redhead balding or a gray head with full scalp hair. In humans two distinct forces, night sleep exposure/enclosure, sun skin exposure/enclosure, produced today's hair traits.

> . .
> When and why do you see "body hair
> reduction'?
> . .
> >> it also makes no sense to claim that such
> >> dense hair
> >. .
> > Tightly-coiled Afro hair is not "dense" hair.
> . .
> Please find an image of natural fully-grown
> 'tightly-coiled Afro hair'. I can't. I suspect
> that you won't be able to either. In other
> words, you're imagining something that
> does not exist.

Typical black people without European admixture have tightly coiled hair.
People with only 20% African recent heritage have loosely coiled hair.

> . .
> > It protects against tropical-year-round sun UV.
> . .
> Why does the scalp need that protection
> when the rest of the body doesn't?
> . .

The scalp receives the maximum exposure in an obligate orthograde biped.

> The scalp receives the maximum exposure in an obligate orthograde biped.

:-DDD You haven't seen my baldness.

On Sunday 17 April 2022 at 14:21:04 UTC+1, DD'eDeN aka note/nickname/alas_my_loves wrote:

>>> Black people have tightly coiled body hair, so tight-coiling preceded body hair reduction.
> . .
> Amend: the curling of body hair began before Hs body hair greatly reduced, but at a very
> slow rate of change until proto-agriculture, and both are still under selection. Body hair/fur
> reduction first began with the change from fully exposed arboreal branch/tree-fork sleeping
> (OWM, gibbons) to partly exposed arboreal bowl nesting (great apes) and increased in the
> change from arboreal bowl nesting to non-exposed terrestrial dome dwelling (Homo) while
> under forest canopy. Note that body hair reduction (and concomitant scalp hair lengthening)
> was mainly a nocturnal/inactivity selection trait, mostly connected to prone/supine posture
> relative to enclosure; while body & scalp hair curling was mainly a diurnal/activity selection
> trait mostly connected to upright orthograde posture relative to exposure to sunlight and
> convective air currents. A parallel condition today is in mature people, hair loss is
> independent of hair graying but both can occur simultaneously or sequentially, a redhead
> balding or a gray head with full scalp hair. In humans two distinct forces, night sleep
> exposure/enclosure, sun skin exposure/enclosure, produced today's hair traits.
.. .
All far too speculative for me
.. .
>> When and why do you see "body hair
>> reduction'?
>> . .
>> >> it also makes no sense to claim that such
>> >> dense hair
>> >. .
>> > Tightly-coiled Afro hair is not "dense" hair.
>> . .
>> Please find an image of natural fully-grown
>> 'tightly-coiled Afro hair'. I can't. I suspect
>> that you won't be able to either. In other
>> words, you're imagining something that
>> does not exist.
>. .
> Typical black people without European admixture have tightly coiled hair.
. .
Where is the image that I requested?
.. .
> People with only 20% African recent heritage have loosely coiled hair.
.. .
It is generally accepted that our ancestors
were African -- and presumably had normal
Afro hair.
.. .
>>> It protects against tropical-year-round sun UV.
>> . .
>> Why does the scalp need that protection
>> when the rest of the body doesn't?
>. .
> The scalp receives the maximum exposure in an obligate orthograde biped.
.. .
Not an adequate answer for the enormous
difference in hair cover.

On Sunday, April 17, 2022 at 1:29:03 PM UTC-4, Paul Crowley wrote:
> On Sunday 17 April 2022 at 14:21:04 UTC+1, DD'eDeN aka note/nickname/alas_my_loves wrote:
>
> >>> Black people have tightly coiled body hair, so tight-coiling preceded body hair reduction.
> > . .
> > Amend: the curling of body hair began before Hs body hair greatly reduced, but at a very
> > slow rate of change until proto-agriculture, and both are still under selection. Body hair/fur
> > reduction first began with the change from fully exposed arboreal branch/tree-fork sleeping
> > (OWM, gibbons) to partly exposed arboreal bowl nesting (great apes) and increased in the
> > change from arboreal bowl nesting to non-exposed terrestrial dome dwelling (Homo) while
> > under forest canopy. Note that body hair reduction (and concomitant scalp hair lengthening)
> > was mainly a nocturnal/inactivity selection trait, mostly connected to prone/supine posture
> > relative to enclosure; while body & scalp hair curling was mainly a diurnal/activity selection
> > trait mostly connected to upright orthograde posture relative to exposure to sunlight and
> > convective air currents. A parallel condition today is in mature people, hair loss is
> > independent of hair graying but both can occur simultaneously or sequentially, a redhead
> > balding or a gray head with full scalp hair. In humans two distinct forces, night sleep
> > exposure/enclosure, sun skin exposure/enclosure, produced today's hair traits.
> . .
> All far too speculative for me
> . .
> >> When and why do you see "body hair
> >> reduction'?
> >> . .
> >> >> it also makes no sense to claim that such
> >> >> dense hair
> >> >. .
> >> > Tightly-coiled Afro hair is not "dense" hair.
> >> . .
> >> Please find an image of natural fully-grown
> >> 'tightly-coiled Afro hair'. I can't. I suspect
> >> that you won't be able to either. In other
> >> words, you're imagining something that
> >> does not exist.
> >. .
> > Typical black people without European admixture have tightly coiled hair.
> . .
> Where is the image that I requested?
> . .
> > People with only 20% African recent heritage have loosely coiled hair.
> . .
> It is generally accepted that our ancestors
> were African -- and presumably had normal
> Afro hair.
> . .
> >>> It protects against tropical-year-round sun UV.
> >> . .
> >> Why does the scalp need that protection
> >> when the rest of the body doesn't?
> >. .
> > The scalp receives the maximum exposure in an obligate orthograde biped.
> . .
> Not an adequate answer for the enormous
> difference in hair cover.
PC falling back on his usual poli crap.

On Sunday, April 17, 2022 at 12:31:41 PM UTC-4, littor...@gmail.com wrote:
> > The scalp receives the maximum exposure in an obligate orthograde biped.
> :-DDD You haven't seen my baldness.

A few days ago I shaved my scalp, completely bald, to prepare for hot humid summer here in Miami; now just my long white beard remains. I'll never go bald naturally, though my hairline has receded 1"/2.5cm since my youth.

On Monday, April 18, 2022 at 1:54:39 AM UTC+1, DD'eDeN aka note/nickname/alas_my_loves wrote:

>>>>> Tightly-coiled Afro hair is not "dense" hair.
>>>> . .
>>>> Please find an image of natural fully-grown
>>>> 'tightly-coiled Afro hair'. I can't. I suspect
>>>> that you won't be able to either. In other
>>>> words, you're imagining something that
>>>> does not exist.
>>>. .
>>> Typical black people without European admixture have tightly coiled hair.
>> . .
>> Where is the image that I requested?
.. .
Sub-Saharan Africa has a population
approaching one billion.
.. .
Please find an image of natural fully-grown
'tightly-coiled Afro hair' -- OR admit that it
does not exist.