Re: Airsacs (Re: Ealine Morgan

On 20 Jan, 01:38, Marc Verhaegen <m_verhae...@xxxxxxxxx> wrote:
Op 19-01-2008 15:17, in artikel
90e19307-35ff-413b-8850-34a788086...@xxxxxxxxxxxxxxxxxxxxxxxxxxxx,hazchem
<hazc...@xxxxxxxxxxx> schreef:

If it was really true that Natural Selection favours elongated humans
in dry hot conditions,

Waders typically have very long & slender legs, but not necessarily other
extremities AFAIK. Mammals living in hot conditions (also dry?), eg, desert
foxes as opposed to polar foxes, have long extremities, esp.ears, snout,
tail...  
(The protruding nose of neandertals excludes living exclusively in cold
terrestrial conditions.  AFAIK all Hn are found next to coasts (Gibraltar,
Italian coasts...), swamps, riversides or combinations (Mt.Carmel...).  Some
of their tools have traces of cattails.  Several Hn skulls have auditory
exostoses. The Banyoles molar microwear shows their diet sometimes included
dried fish. Their dense bones exclude frequent/long running.  Their large
paranasal sinuses suggest (parttime?) wading/surface-swimming.  Isotopic
data (diet) resemble those of wolves & mammoths. All this suggests they
still spend some time in the water, collecting cattails & aq.or waterside
plants, collecting drowned carcasses, possibly killing prey in the water,
probably (bone density) collecting sessile aq.foods etc. No dobut their
lifestyle overlapped with that of waterside humans today, but the Richard
cs.2001 PNAS paper suggests they, unlike Hs, didn't use nets or boats.)

then we would expect 2 things. We would expect
all elongated people to live in dry hot conditions, not swampy wet
conditions as do the Nuer and Dinka. We would also expect all people
living in hot dry conditions to be elongated, unless they had not
inhabited that region for a long time. The San or Bushmen people are
the second shortest in the world, which is not surprising considering
that they conform to Bergmann's Rule. They have a higher surface area
compared to their volume or weight and so lose heat more rapidly.

Yes.

Hazchem, what is the Nuer & Dinka livestyle? Do they live in forests? on dry
ground mostly? collect some waterside or aquatic foods? wading? swimming? in
boats?

AFAIK they live from their cattle, as do the Masaii. They drink milk
and maybe blood sometimes too. I think they have to move seasonally
because land is flooded, and it is grassy rather than forested.

Elongation may be something to do with heat adaption, but it is not as
good at that as the San type or the Pygmy type. One book that I have
gives a figure or 301 centimetres squared per kilogram for a typical
Nilotic and 314 centimetres squared per kilogram for a Pygmy. So
Pygmies have a higher surface area compared to volume or weight than
Nilotics and so can lose heat more rapidly. The same would be true of
San people.

Interesting.
Note pygmies are smaller (= moving through vegetation?): that alone can
explain more cm2/kg?

Another book says that cylinders of the same diameter always have the
same surface area. This is not true, as it only takes into account the
lateral surface area. This attempts to demonstrate that people who are
narrow, irrespective of their height, have the same surface area. Not
so.

OK.

The tallest Aborigines are in the humid tropical North of Australia.
The figure I have for their height is 171 cm or 5 feet 7 inches, which
doesn't sound especially tall to me. Aborigines have shorter trunks/
torsos than most people but longer legs and arms. So they conform to
both Bergmann's Rule and Allen's Rule. They seem to have the small
trunk/torso of the San with the long arms and legs of the Nilote.
Because of the short trunk/torso I would not call them elongated.
Nilotic peoples have long trunks.

Are both arms & legs elongated? or esp.legs?

I assumed that their arms would be long too, to conform with Allen's
rule (longer limbs allow more heat loss), but the information I have
does not make that clear.

Humans are much more dependant on water that any savanna animal. Ten
percent dehydration kills humans but it takes 20 percent to kill cats
or dogs. Hot-country animals such as hunting dogs are able to survive
rises in body temperature to over 40 degrees centigrade. These levels
would kill any human being. Humans sweat and they have dilute urine
and wet poo. Sweating can lead to the loss of 15 litres (3 gallons) of
water a day under a tropical sun. Savanna herbivores can go all day
without drinking.
How is Homo erectus going to kill a kudu anyway? Even if a kudu has
stopped running because it is exausted, it can still defend itself.
Did Homo erectus carry spears when they were running? Had spears been
invented? How do you defend yourself against lions, hyenas and
leopards when you are carring kilos of dripping meat across 20 miles
of savanna to the females and children before nightfall?

Nice to see here people with common sense.


--Marc

.

Relevant Pages

  • Re: Airsacs (Re: Ealine Morgan
    ... Waders typically have very long & slender legs, ... Mammals living in hot conditions (also dry?), eg, desert ... Pygmies have a higher surface area compared to volume or weight than ...
    (sci.anthropology.paleo)
  • Re: Airsacs (Re: Ealine Morgan
    ... Mammals living in hot conditions (also dry?), eg, desert ... Pygmies have a higher surface area compared to volume or weight than ... would kill any human being. ...
    (sci.anthropology.paleo)
  • Re: Thunderstorm
    ... A thin windproof gilet, and maybe a pair of Rain Legs, mean that even if the torso gets soaked to the skin the wind won't blow the layer of warm water away. ... The only thing you really need to keep dry is your change of clothes for when you reach your destination. ... Everything you say above is really good stuff but there are some people who are totally clobbered by a little bit of cold and who take, literally hours to warm up or 'catch cold'. ...
    (uk.rec.cycling)
  • Re: Putting legs on machine with new decals
    ... easier and the stickers actually adhere BETTER than the dry method. ... tested the different methods using some left over strips of AFM decals ... Push the legs upward as ...
    (rec.games.pinball)
  • Re: A1C and Itchy legs
    ... Rindee wrote: ... > dry skin. ... my legs get dry & itchy but I can tell that they're dry. ... It's not spots of dry skin, the whole lower leg is just very dry and ...
    (misc.health.diabetes)