Re: Hands and brains

[KellySt@aol.com]

To: Timothy van der Linden)


> To Kelly:
> 
> >Yeah, Its assumed that you need a minimum size to have enough cells, for
> >enough interconnections, to get a complex enough brain; But you also need
a
> >big enough brain to body ration so the brain has enough excess power to
spare
> >on complexity.
> 
> But why do elephants have such big brains (3 to 4 times larger than
humans)?

They need the nuerons to run their big bodies, which are dozens of times
humans.



> >Automation allows a few skilled people to do the work of a larger number
of
> >people without automation.  It does not allow the automation system to
work
> >by itself without people.  As long as their are people to fix and operate
it,
> >automate systems will work well and productivly.  Which is why all large
> >manufacturing industries use them.
> 
> But that means that much less people can do the job

Yes.


> >> Forget the predictions, it is proven than several gasses like CO2 and
SO2
> >> have very well insulating properties. So the fact that these gasses are
> >> present in abundance on Venus means that a greenhouse-effect is 
> >> responsable for the high temperature.
> >
> >No it doesn't, it just meen their are insulating gases in the air.  It
> >doesn't even tell you if they are keeping heat in, or out.
> 
> It's keeping the heat in: Greenhouse gasses are more opaque planetary
> radiation than for solar radiation. Solar radiation is what directly comes
> from the Sun and planetary radiation is 

I know the theory, I also know their is no data to support it.

> As for the debacle about Earth's greenhouse effect, there are only doubts
> about the quantity of the temperature increase caused by the greenhouse
> gasses. Also it is argued if the greenhouse gasses are the only reason for
> temperature increase.

It is also argued if the earth is getting warmer or cooler.  NASA went back
over 25-30 years of satelihgt scans.  They could have detected a change as
small as 1/5th the smallest variation predicted by any of the green house
theories.  They didn't find it.  Longer term arcio-climatology studies have
shown a cooling since the mid 1800, a warming from the 1700, and a long term
cooling over the last 800 years.

> >> Yes, but that is because Earth has a biosphere. If Earth had to do
without
> >> that and it would be moved to the place of Venus, then is would heat up
and
> >> once the greenhouse-effect took over there wouldn't be a way back.
> >
> >No, earth biosphere trims its temperature a bit, but not by hundreds of
> >degrees!  If that were true Earth would have been unable to ever evolve
life.
> 
> To that I agree, but as long the greenhouse effect is not too large the
> temperatures will not become so high that no live can exist. At the
> light-side of the moon you will freeze to death (assuming you weren't
> choking first) this is because there are no gasses to keep the heat in. The
> only heat there is radiative heat.

How do you freeze to death at 200 degrees F?  Trust me, freezing wasn't a
problem on the moon in full sunlight.

> >>>In a world without photosyntisis the non-oxegen forms could still
> >>>dominate.
> >> 
> >> How? If they used chemicals for their energy, then the supply of those
> >> chemicals better be almost infinite. Most of the chemicals that
organisms
> >> use these days are recycled by using photosyntesis. Only a small
fraction
> >>of chemicals is freed by vulcanos, hardly enough to sustain a group of
> >>lifeforms.
> >
> >Depends on the planets and its chemistry.
> 
> I think that if chemicals are not recycled any amount is used up in a
> relative short period. (If water and carbondioxide where not recycled by
> plants, animal (non photosynthesis) live would very soon die away).

But the chemicals are being recycled by the planetary geo-processes, and they
have sustained their local populations for a very long time.

> >> No, we were apes before we had big brains, and apes are not preditors.
> >
> >We evolved from chimps, which are predators.  (Unlike Gorillas.)  Those
> >chimps evolved (after some odd twists) into plains preditors and
scavengers.
> 
> I've never heard that before, so I'm not certain.
> 
> >We developed that (and primative tool making), before our brains expanded
> >much.
> 
> I've seen a TV-series (again :) ) that tried to explain that the human
brain
> expanded as soon as it began standing up. The reason for that was the
> temperature difference between 0.8 metre (on 4 legs) and 1.5 metres (on 2
> legs) above the ground. -------
> One question remains however, why didn't they get a bigger brain while in
> the forest before the mountain ridge appeared?

Or why didn'tproto apes in cooler climates develop it.  Besides, humans are
warm blooded.  They keep thie brain tissue withing a fraction of a degree of
temp.

> >> Indeed, most of our brain isn't devoted to anything as far as we know.
--
> >
> >Actually we do know what all the centers of the brain do, just not how
they
> >do it.
> 
> Why have I heard so many times that 90% of the brain (or did they mean the
> cerebrum) is unused?

Thats one of those old saying that have been around forever.  Like the idea
that aerodynamics says a bee can't fly.  Untrue, but so memorable that
everyone keeps saying it.

> >> --- I
> >> meant that a large part is devoted to what you can do with your hands.
> >> Suppose you have a large brain, but no hands/legs to make use of it.
There
> >> would not be any advantage then to have a bigger brain, so it would not
> >>evolve.
> >
> >The biggest section of the human brain evolved to use the eyes, not hands.
> > Niether are used in itelegence, that evolved separatly.
> 
> Yes, I'm slowly seeing that size is not the most important factor and that
> the largest part of the brain was and is already available. Could it be
that
> the use of hands and its applications involved a completely new way of
> neuron interconnection which had intelligence as convenient side product?
> 
> If I'm not right about this hands->brain connection, then why did we get a
> bigger brain?

Humans have an odd brain hand trick we retained since we were tree dwelers.
 It makes certain types of eye hand coordination easier (real important when
your jumping for a branch) but humans brains developed long after  our bodies
and hands were developed.

Why did humans develop such powefull minds?  Thats a hotly debateed question.

Kelly