From: John K Clark (johnkc@well.com)
Date: Sun Jan 19 1997 - 22:52:50 MST
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Michael Lorrey <retroman@tpk.net> Wrote:
>>John:
>>A cheetah would have to be within 100 yards of me
>>to catch me? That is crazy.
>Michael:
>Not at all. Take a human 100 yards away from a cheetah. A
>cheetah has a 0-60 time of around 6 seconds. A human has a
>0-18 time of around 3 seconds. Assuming the cheetah can keep
>up the 60 mph once she reaches it for over two seconds, they
>cheetah will catch the human at 165 yards, 8 seconds from
>starting. Give the human an extra 30 yards (a 130 yard
>distance) and the human will be over 200 yards before the
>cheetah can catch him, by which time the cheetah will be
>exhausted enough for the human to brain her a good one. (the
>human will have run for only 70-80 yards, so will not be
>winded.)
Ok I looked it up. Sustained speeds of 90mph have been attributed to the
cheetah but are not considered reliable. The fastest measured speed of a
captive cheetah was an average of 43.4 mph over a distance of 1035 feet at a
oval greyhound track. The animal was not running flat out (she was not hungry)
and had great difficulty at the steep curves. The fastest measured speed of
a cheetah in the wild was between 60 and 63 mph on straight level ground over
a distance of 1641 feet. I would not want to be 300 feet away from a pack of
hungry cheetahs, they would not need to run to catch me, they could just
shuffle off in my direction.
>with group behavior, you always want one lookout looking all
>the time.
So all the time you will have a big neon sign high up in the air saying
"FRESH DELICIOUS MEAT HERE, VERY EASY TO CATCH".
>huh, you've never seen meerkats then. They spend a lot of
>time on two feet, doing sentry work both on the hunt and
>around the burrow.
Sure, but when they need to move fast, like when something wants to eat them,
they run on 4 legs.
>Looking at how humans developed their materials technology,
>they started with the softest and most malleable materials
>first.
Why? Flint is very hard but also extremely brittle, it's easy to chip off a
piece and you have a razor sharp blade. Lots of such blades were made,
one million years after bipedalism was fully developed, but not one has ever
been found that dated from Lucy's day.
>A sharp slate piece can whittle wood very easily.
But not the slightest evidence of such a tool making factory has ever been
found, not from Lucy's day. Two and a half million years ago, a million years
after Lucy, it's a very different story.
>Bows and arrows date to the dawn of recorded history,
Yes, and recorded history is only a few thousand years old.
>your statement is now completely wrong,thanks to the Tyrolian
>Ice Man discovered a couple years ago. He lived in the last
>ice age, around 15k-20k years ago, and had guess what? a bow
>and arrows in his posession!
I am talking about something over 200 times as old and an animal over 200
times as dumb. Are you seriously trying to tell me that a bow and arrow would
be easier to make than a sharpened stone or bone? Are you seriously trying to
tell me that a bow and arrow could even be made without using a sharpened
stone or bone as a tool?
>>John:
>>The Kalahari Bush people are as smart as you or me
>Michael:
>If they are, why are they still living in lean-to's?
Because they were caught in a backwater of cultural evolution. Just an instant
ago, a few thousand years, everybody lived as they do, and that is far too
short for Darwinian biological evolution to be important, but more than enough
time for Lamarckian Cultural Evolution to have a profound effect. I should
also say that it takes far more brain power to survive in the Kalahari Bush
People's world that in our own
>>John:
>>Three and a half million years ago Lucy was fully bipedal
>>and had a hand almost as good as ours, but she was dumb,
>>her brain ranged from 380 to 450 cc, modern humans have a
>>range of 1000 to well over 2000 cc.
>Michael:
>you fail to mention how tall she was or how much she massed.
>What is important is the brain/body mass ratio.
Lucy was a little taller than a modern chimp and a little thinner, weighed
about the same. On average a chimp's brain is about 350cc.
>Erectus was originally dated to less than 1.5 mill years.
>Now hes as far back as 4-5 million.
But the important thing is the line of decent that uniquely led to humans, as
opposed to some other animal. This line is much shorter than thought 20 years
ago, it's only 5 or 6 million years old. That lends support to the idea that
the Evolution of humans was not an inevitable outcome but a lucky accident.
>maybe your not smart enough to be a prehuman.
If I was in a nasty mood as you seem to be, I would say that at least I'm
smart enough to know I hadn't invented a machine that violates the law of
conservation of momentum, but I'm not so I won't.
On Sun, 19 Jan 1997 J de Lyser <gd33463@glo.be> Wrote:
>One of the advantages of bipedalism could be to look
>imposing, bears stand on their hind legs when they take on a
>defensive posture.
Yes, but again, bears are not bipedal because you don't need to be bipedal to
do that.
>Correct me if i'm wrong, but there we're also no lions at
>the time of Autralopethicus Afarensis.
True, but there were plenty of other large fast carnivores, like the ancestor
of lions and saber tooth tigers.
>Australopithecus Afarensis was capable of defending himself
>against predators, as it seems unlikely that they had much
>higer reproduction rates, or much slower pregnancy times.
There is not a particle of evidence that Australopithecus Afarensis engaged
in hunting of any sort, but yes, it must have had some method of dealing with
predators, because despite being slow and weak and having no tools, Lucy's
kind not only survived they thrived. The mystery is why.
John K Clark johnkc@well.com
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