Why does exercise make you fit?

[Peter Webb]

Or rather, lack of exercise make you unfit?

I can understand why (in an evolutionary sense) the human body
is designed to only add muscle mass when muscles are
overloaded. Carrying around huge skeletal muscles if they are
not needed is inefficient, as they require extra food to
sustain. Better to have only the muscles you need. So the body
gets rid of the muscles when they are not needed.

But why does it get unfit? There seems to be absolutely no
advantage (in an evolutionary sense) to being unfit, and many
disadvantages. So why doesn't your body maintain the
adaptations it makes to exercise, even when it is not being
exercised?

Peter Webb

[Wayne S. H]

Peter Webb wrote:

> Or rather, lack of exercise make you unfit?
>
> I can understand why (in an evolutionary sense) the human
> body is designed to only add muscle mass when muscles are
> overloaded. Carrying around huge skeletal muscles if they
> are not needed is inefficient, as they require extra food to
> sustain. Better to have only the muscles you need. So the
> body gets rid of the muscles when they are not needed.
>
> But why does it get unfit? There seems to be absolutely no
> advantage (in an evolutionary sense) to being unfit, and
> many disadvantages.

In that case, you're imagination is failing you. It takes
extra energy and nutrients to maintain fitness.

> So why doesn't your body maintain the adaptations it makes
> to exercise, even when it is not being exercised?

As Feynman was fond of saying, "I can tell you how things
happen, but not why."

-Wayne

[Mistress K]

"Peter Webb" <pwebb@REMOVESPAMopticon-aust.com.au> wrote in
message news:3d53c984$0$29911$afc38c87@news.optusnet.com.au...
>
> But why does it get unfit? There seems to be absolutely no
> advantage (in
an
> evolutionary sense) to being unfit, and many disadvantages.
> So why doesn't your body maintain the adaptations it makes
> to exercise, even when it is
not
> being exercised?
>

The body responds dynamically to its environment. If it does
not perceive a need for fitness because no demands are being
made on it (consider our current state of general social
fatassedness and laziness), then it adapts accordingly. Being
unfit allows it to be thrifty, in that it is not expending
resources responding to demands that aren't there.

Krista

--
--------------------
www.stumptuous.com/weights.html www.trans-health.com
mistresskrista@stumptuous.com

[Stephen Di]

In article <3d53c984$0$29911$afc38c87@news.optusnet.com.au>,
"Peter Webb" <pwebb@REMOVESPAMopticon-aust.com.au> wrote:

> Or rather, lack of exercise make you unfit?
>
> I can understand why (in an evolutionary sense) the human
> body is designed to only add muscle mass when muscles are
> overloaded. Carrying around huge skeletal muscles if they
> are not needed is inefficient, as they require extra food to
> sustain. Better to have only the muscles you need. So the
> body gets rid of the muscles when they are not needed.
>
> But why does it get unfit? There seems to be absolutely no
> advantage (in an evolutionary sense) to being unfit, and
> many disadvantages. So why doesn't your body maintain the
> adaptations it makes to exercise, even when it is not being
> exercised?
>
> Peter Webb
>
>
>

Here's one _possible_ explanation I can think of. (I assume
you refer to cardiovasculate fitness.)

In the natural state of our ancesters, physical demands were
_constantly_ being made on the organism, so it could develop
mechanicsms that rely on those demands to maintain fitness.
There would be no serious evolutionary pressure to retain
fitness without use, because there was continual use, by
necessity.

Stephen Diamond

[Mark Donoh]

"Peter Webb" <pwebb@REMOVESPAMopticon-aust.com.au> writes:

>Or rather, lack of exercise make you unfit?

>But why does it get unfit? There seems to be absolutely no
>advantage (in an evolutionary sense) to being unfit, and many
>disadvantages. So why doesn't your body maintain the
>adaptations it makes to exercise, even when it is not being
>exercised?

Its not an evolution or genetics thing - its more of an
environment thing. You will adapt to your environment. If that
environment includes a couch or seat for 18 hours a day, then
you will adapt to suit that environment
(ie: you will grow a fat arse - an "advantage" for spreading
your weight over a couch!).

Another important life principle:

In life, if you practice something for long enough,
you will get good at it.

So, if you lift weights for long enough, you get good at it;
If you are a habitual cardio person, you get good at that
too. BUT, if you sit on your arse all day, well, you get
good at that.

Does this make sense?

Mark D.
--
Please note, none of the opinions expressed above are grounded
in fact; the author admits no liability resulting from
consequences arising due to any use of nonsensical
information.

[David Cohe]

"Wayne S. Hill" <hillw4@asme.org> wrote in message
news:Xns926568E164544wshill@130.133.1.4...
> Peter Webb wrote:
>
> > Or rather, lack of exercise make you unfit?
> >
> > I can understand why (in an evolutionary sense) the human
> > body is designed to only add muscle mass when muscles are
> > overloaded. Carrying around huge skeletal muscles if they
> > are not needed is inefficient, as they require extra food
> > to sustain. Better to have only the muscles you need. So
> > the body gets rid of the muscles when they are not needed.
> >
> > But why does it get unfit? There seems to be absolutely no
> > advantage (in an evolutionary sense) to being unfit, and
> > many disadvantages.
>
> In that case, you're imagination is failing you. It takes
> extra energy and nutrients to maintain fitness.
>
> > So why doesn't your body maintain the adaptations it makes
> > to exercise, even when it is not being exercised?
>
> As Feynman was fond of saying, "I can tell you how things
> happen, but not why."

Surely, you're joking, Mr Hill.

All posts that result in a Richard Feynman quote get
extra points.

David
>
> -Wayne

[Stephen Di]

In article <Xns926568E164544wshill@130.133.1.4>, "Wayne S.
Hill" <hillw4@asme.org> wrote:

> As Feynman was fond of saying, "I can tell you how things
> happen, but not why."

You can't say "why" in physics, but you can in biology. The
answer to why questions in biology adverts to the specific
pressures of natural selection.

Stephen Diamond

[Peter Webb]

Thanks, a plausible answer. "Survival of the fittest" indeed!

Also provides a reasonable explanation of why evolution allows
individuals can continually eat and turn into 200 kg couch
potatos, when fat levels of this magnitude would seem to be
counter-productive for survival and reproduction.

"Stephen Diamond" <stephend15@mindspring.com> wrote in message
news:stephend15-C384FD.22310009082002@news.mindspring.com...
>In article <3d53c984$0$29911$afc38c87@news.optusnet.com.au>,
> "Peter Webb" <pwebb@REMOVESPAMopticon-aust.com.au> wrote:
>
> > Or rather, lack of exercise make you unfit?
> >
> > I can understand why (in an evolutionary sense) the human
> > body is
designed
> > to only add muscle mass when muscles are overloaded.
> > Carrying around
huge
> > skeletal muscles if they are not needed is inefficient, as
> > they require extra food to sustain. Better to have only
> > the muscles you need. So the
body
> > gets rid of the muscles when they are not needed.
> >
> > But why does it get unfit? There seems to be absolutely no
> > advantage (in
an
> > evolutionary sense) to being unfit, and many
> > disadvantages. So why
doesn't
> > your body maintain the adaptations it makes to exercise,
> > even when it is
not
> > being exercised?
> >
> > Peter Webb
> >
> >
> >
>
> Here's one _possible_ explanation I can think of. (I assume
> you refer to cardiovasculate fitness.)
>
> In the natural state of our ancesters, physical demands were
> _constantly_ being made on the organism, so it could develop
> mechanicsms that rely on those demands to maintain fitness.
> There would be no serious evolutionary pressure to retain
> fitness without use, because there was continual use, by
> necessity.
>
> Stephen Diamond

[tribalzida]

In news:misc.fitness.weights, "Mistress Krista"
<mistresskrista@stumptuous.com*rem0vethis*> posted on Fri,
09 Aug 2002
14:23:39 GMT:

> The body responds dynamically to its environment. If it does
> not perceive a need for fitness because no demands are being
> made on it (consider our current state of general social
> fatassedness and laziness), then it adapts accordingly.
> Being unfit allows it to be thrifty, in that it is not
> expending resources responding to demands that aren't there.

Digestive systems get good workouts all the time, though, as
it processes all those cheeseburgers and slices of pizza. I
would imagine that at a time in human evolution when the least
amount of work is required, we have the largest amount of food
intake. We don't have to chase our food and kill it. We lazily
stroll through a supermarket and drop it in a basket.

Damaeus

[Peter Webb]

"Mark Donohoe" <mdonohoe@uow.edu.au> wrote in message
news:3d563c9d$1@news.uow.edu.au...
> "Peter Webb" <pwebb@REMOVESPAMopticon-aust.com.au> writes:
>
> >Or rather, lack of exercise make you unfit?
>
> >But why does it get unfit? There seems to be absolutely no
> >advantage (in
an
> >evolutionary sense) to being unfit, and many
> >disadvantages. So why
doesn't
> >your body maintain the adaptations it makes to exercise,
> >even when it is
not
> >being exercised?
>
>
> Its not an evolution or genetics thing - its more of an
> environment thing. You will adapt to your environment. If
> that environment includes a couch or seat for 18 hours a
> day, then you will adapt to suit that environment
> (ie: you will grow a fat arse - an "advantage" for spreading
> your weight over a couch!).
>
> Another important life principle:
>
> In life, if you practice something for long enough, you will
> get good at it.
>
> So, if you lift weights for long enough, you get good at it;
> If you are a habitual cardio person, you get good at that
> too. BUT, if you sit on your arse all day, well, you get
> good at that.
>
> Does this make sense?

No, it doesn't. Why is being unfit a useful adaptation to a
sedentary lifestyle? How does being unfit help you sit on your
arse all day? I can think of several ways in which it is a
disadvantage - for example, it increases your chances of
having a heart attack. Your body makes all of these changes
when you get fit - why does it change back when you stop
exercising? Wouldn't it make more sense if your body retained
the adaptations it makes when it is fit even when it is unfit?

[Wayne S. H]

Stephen Diamond wrote:

> "Wayne S. Hill" wrote:
>
>> As Feynman was fond of saying, "I can tell you how things
>> happen, but not why."
>
> You can't say "why" in physics, but you can in biology. The
> answer to why questions in biology adverts to the specific
> pressures of natural selection.

Doesn't that make you stop and think: what is it about biology
that allows you to say "why", but physics can't? Stripped to
its fundamentals, biology is physics, so there must be some
rubicon that is crossed that allows "why" to be answered on
one side but not to be answered on the other. I don't believe
that line exists.

-Wayne

[Lyle McDon]

Peter Webb wrote:
>
> "Mark Donohoe" <mdonohoe@uow.edu.au> wrote in message
> news:3d563c9d$1@news.uow.edu.au...
> > "Peter Webb" <pwebb@REMOVESPAMopticon-aust.com.au> writes:
> >
> > >Or rather, lack of exercise make you unfit?
> >
> > >But why does it get unfit? There seems to be absolutely
> > >no advantage (in
> an
> > >evolutionary sense) to being unfit, and many
> > >disadvantages. So why
> doesn't
> > >your body maintain the adaptations it makes to exercise,
> > >even when it is
> not
> > >being exercised?
> >
> >
> > Its not an evolution or genetics thing - its more of an
> > environment thing. You will adapt to your environment. If
> > that environment includes a couch or seat for 18 hours a
> > day, then you will adapt to suit that environment
> > (ie: you will grow a fat arse - an "advantage" for
> > spreading your weight over a couch!).
> >
> > Another important life principle:
> >
> > In life, if you practice something for long enough, you
> > will get good at it.
> >
> > So, if you lift weights for long enough, you get good at
> > it; If you are a habitual cardio person, you get good at
> > that too. BUT, if you sit on your arse all day, well, you
> > get good at that.
> >
> > Does this make sense?
>
> No, it doesn't.

that's because what he wrote is sort of backwards. It's not
that your body is adapating to being sedentary. It's
de-adapting from not being active. These are slightly
different issues.

< Why is being unfit a useful adaptation to a sedentary
> lifestyle?

Because the body is not expending energy on an adapation that
it doesn't feel the need to maintain.

> How does being unfit help you sit on your arse all day? I
> can think of several ways in which it is a disadvantage -
> for example, it increases your chances of having a heart
> attack. Your body makes all of these changes when you get
> fit - why does it change back when you stop exercising?
> Wouldn't it make more sense if your body retained the
> adaptations it makes when it is fit even when it is unfit?

Didn't you read all of the other responses? Nevermind, I'm
being rhetorical.

In the absence of a stimuli (i.e. activity), the body has no
need to expend energy maintaining that adaptation.

Because, from a survival standpoint, energetic efficiency
(esp. short-term) is of paramount importance. Your body isn't
looking at what might happen 2 years down the road. If you
don't use something, the body sees no reason to maintain it so
it goes away.

Example: when you don't eat carbs for a while, your body quits
making the enzymes for carb digestion in the gut. This makes
perfect sense to your body: why waste energy, protein, etc to
maintain something that yo'ure not using. The fact that you
*might* eat carbs in the future doesn't matter.

Same deal here: in the absense of a stimuli (exercise), the
body would be wasting energy by maintaining fitness. So the
adapation goes away. Your mistake seems to be in ascribing
some sort of inherent 'wisdom' to the body, that it knows
that de-adapting increaes the risk of heart attack. Doesn't
work that way.

The body responds in a dynamic fashion to stimuli: expending
energy when necessary, and conserving energy when not
necessary. Exercise and you send a stimulus that says 'It's
good to expend energy on this', take away that stimulus and
the signal is no longer sent, so the body doesn't waste
energy on it.

What is hard to understand about this?

Lyle

[Lyle McDon]

"Wayne S. Hill" wrote:
>
> Stephen Diamond wrote:
>
> > "Wayne S. Hill" wrote:
> >
> >> As Feynman was fond of saying, "I can tell you how things
> >> happen, but not why."
> >
> > You can't say "why" in physics, but you can in biology.
> > The answer to why questions in biology adverts to the
> > specific pressures of natural selection.
>
> Doesn't that make you stop and think: what is it about
> biology that allows you to say "why", but physics can't?
> Stripped to its fundamentals, biology is physics, so there
> must be some rubicon that is crossed that allows "why" to be
> answered on one side but not to be answered on the other.

Because the question of why implies that there was some
purpose for it to have occurred.

For example, that the body will increases and decrease
adapation to imposed demand implies purpose: the body only
expends energy (being finite) on processes that it is 'told'
(told = giving the biochemical stimulus) to do so. That's
'why' fitness goes away if you stop training: the body has no
incentive to expend its finite energy on processes that aren't
being used. Being able to decrease energy expended for
processes not being used conferred a specific advantage. The
opposite situation, expending energy on a process not being
used, would have made no sense. In fact, it would have been
detrimental becacues the body is now expending it's finite
energy stores on a process it doesn't 'need'.

That women adapt to dieting moreso than men occurred for a
purpose: evolutionarily, women had the ultimate control over
propagation of the species. Being able to defend against
famines conferred a specific advantage. Not being able to
defend against famines would have been quite detrimental to
our survival.

In contrast, that we primarily absorb L vs D-amino acids has
no purpose. it confers no specific advantage and there's no
reason 'why'. It was simply what happened at some point way
back when, some system had a mutation that only allowed it to
use one but not the other. Once the 'choice' was made (i.e. we
had adapted to only using one and not the other), it stuck.
But the opposite choice could have occurred just as readily
and it wouldn't have affected the sytstem one way or another.

I don't see how you can apply those types of arguments to
fundamental physics. That is, why one situation confers a
particular advantage over another.

Hmm, maybe that's it, it's a symmetry thing. In situations
where one 'choice' makes more sense than the other, you can
posit why and come up with an answer. In situations where
either choice is equally valid, you can't.

Or maybe I need a nap.

Lyle

[Stephen Di]

In article <Xns92668E1DB367Awshill@130.133.1.4>, "Wayne S.
Hill" <hillw4@asme.org> wrote:

> Stephen Diamond wrote:
>
> > "Wayne S. Hill" wrote:
> >
> >> As Feynman was fond of saying, "I can tell you how things
> >> happen, but not why."
> >
> > You can't say "why" in physics, but you can in biology.
> > The answer to why questions in biology adverts to the
> > specific pressures of natural selection.
>
> Doesn't that make you stop and think: what is it about
> biology that allows you to say "why", but physics can't?
> Stripped to its fundamentals, biology is physics, so there
> must be some rubicon that is crossed that allows "why" to be
> answered on one side but not to be answered on the other. I
> don't believe that line exists.
>
> -Wayne

It is a question of different perspective rather than
different subject matter. There are "why questions" wherever
functionality is addressed. There are, you might say, a
species of why questions in physics; the field in which such
questions are asked is engineering. What is this gadget "for,"
"why" does it exist, ask for the purpose for which it was
constructed.

srd

[Wayne S. H]

Lyle McDonald wrote:

> "Wayne S. Hill" wrote:
>> Stephen Diamond wrote:
>> > "Wayne S. Hill" wrote:
>> >
>> >> As Feynman was fond of saying, "I can tell you how
>> >> things happen, but not why."
>> >
>> > You can't say "why" in physics, but you can in biology.
>> > The answer to why questions in biology adverts to the
>> > specific pressures of natural selection.
>>
>> Doesn't that make you stop and think: what is it about
>> biology that allows you to say "why", but physics can't?
>> Stripped to its fundamentals, biology is physics, so
>> there must be some rubicon that is crossed that allows
>> "why" to be answered on one side but not to be answered
>> on the other.
>
> Because the question of why implies that there was some
> purpose for it to have occurred.

Whose purpose? The organism either adapts or doesn't, either
survives or doesn't. We can see "purpose" in the evolutionary
development of adaptation mechanisms, but that's because we
tend to look for purpose. Self-organization tends to create
novel and ever-finer mechanisms for interacting with your
environment, but is it proper to consider this purpose?

<snip stuff I agree with>

> I don't see how you can apply those types of arguments to
> fundamental physics. That is, why one situation confers a
> particular advantage over another.

A physicist can certainly see that a given biological
adaptation may confer a survival advantage, at least in
certain circumstances, and may see why it does so, but that
does not explain why the adaptation developed. The best we
could hope for is to determine how the adaptation developed.

-Wayne

[Stephen Di]

In article <3D5570DF.B32AC4B2@onr.com>, Lyle McDonald
<lylemcd@onr.com> wrote:

> Hmm, maybe that's it, it's a symmetry thing. In situations
> where one 'choice' makes more sense than the other, you can
> posit why and come up with an answer. In situations where
> either choice is equally valid, you can't.

I think that's right. "Why" implies some sort of selection of
means for ends, whether natural or artificial.

srd

[Wayne S. H]

Stephen Diamond wrote:

> Wayne S. Hill wrote:
>> Stephen Diamond wrote:
>> > "Wayne S. Hill" wrote:
>> >
>> >> As Feynman was fond of saying, "I can tell you how
>> >> things happen, but not why."
>> >
>> > You can't say "why" in physics, but you can in biology.
>> > The answer to why questions in biology adverts to the
>> > specific pressures of natural selection.
>>
>> Doesn't that make you stop and think: what is it about
>> biology that allows you to say "why", but physics can't?
>> Stripped to its fundamentals, biology is physics, so there
>> must be some rubicon that is crossed that allows "why" to
>> be answered on one side but not to be answered on the
>> other. I don't believe that line exists.
>
> It is a question of different perspective rather than
> different subject matter. There are "why questions" wherever
> functionality is addressed. There are, you might say, a
> species of why questions in physics; the field in which such
> questions are asked is engineering. What is this gadget
> "for," "why" does it exist, ask for the purpose for which it
> was constructed.

Nah (says the engineer). I think you've jumped the track.
The why questions you're discussing here are about why
someone knowingly made something the way they did. This is
not the same as asking why a certain adaptation arose in a
biological system.

-Wayne

[Stephen Di]

In article <Xns9266AFB06597Ewshill@130.133.1.4>, "Wayne S.
Hill" <hillw4@asme.org> wrote:

> Whose purpose? The organism either adapts or doesn't, either
> survives or doesn't. We can see "purpose" in the
> evolutionary development of adaptation mechanisms, but
> that's because we tend to look for purpose.
> Self-organization tends to create novel and ever-finer
> mechanisms for interacting with your environment, but is it
> proper to consider this purpose?

>
> <snip stuff I agree with>
>
> > I don't see how you can apply those types of arguments to
> > fundamental physics. That is, why one situation confers a
> > particular advantage over another.
>
> A physicist can certainly see that a given biological
> adaptation may confer a survival advantage, at least in
> certain circumstances, and may see why it does so, but that
> does not explain why the adaptation developed. The best we
> could hope for is to determine how the adaptation developed.
>
Then, do you think the concept of purpose has any relevance to
explainging human action? If so, what rubicon has been crossed
at _that_ point?

srd

[Wayne S. H]

Stephen Diamond wrote:

> Lyle McDonald wrote:
>
>> Hmm, maybe that's it, it's a symmetry thing. In situations
>> where one 'choice' makes more sense than the other, you can
>> posit why and come up with an answer. In situations where
>> either choice is equally valid, you can't.
>
> I think that's right. "Why" implies some sort of selection
> of means for ends, whether natural or artificial.

I believe "why" implies a cognizant selection.

-Wayne

[Wayne S. H]

Stephen Diamond wrote:

> Wayne S. Hill wrote:
>
>> A physicist can certainly see that a given biological
>> adaptation may confer a survival advantage, at least in
>> certain circumstances, and may see why it does so, but that
>> does not explain why the adaptation developed. The best we
>> could hope for is to determine how the adaptation
>> developed.
>>
> Then, do you think the concept of purpose has any relevance
> to explainging human action?

Now THAT's an interesting question.

> If so, what rubicon has been crossed at _that_ point?

The rubicon that's crossed in consideration of action by
humans is the assumption of free will (whether real or not).

-Wayne

[Lyle McDon]

"Wayne S. Hill" wrote:
>
> Stephen Diamond wrote:
>
> > Lyle McDonald wrote:
> >
> >> Hmm, maybe that's it, it's a symmetry thing. In
> >> situations where one 'choice' makes more sense than the
> >> other, you can posit why and come up with an answer. In
> >> situations where either choice is equally valid, you
> >> can't.
> >
> > I think that's right. "Why" implies some sort of selection
> > of means for ends, whether natural or artificial.
>
> I believe "why" implies a cognizant selection.

Cognizant? Speak Englush for the proles, Wayne.

Anyhow, now I think you're being a bit too anthropomorphic
(and coming from the guy, me, who speaks of hormones 'telling'
the brain stuff, that' saying something).

The basic answer to 'why' in terms of evolutionary selection
is simply "BEcause it provided some advantage."

As long as some adaptation gave one critter an advantage over
another, that adapation will proceed. No awareness need enter
the picture.

That is, no animal made a conscious decision to do such and
such (except trying to live up to it's genetic code which
says survive and procreate and we might even argue whether
that's conscious, in the usual sense of the word, or simply a
hardwired behavioral pattern). The adaptation simple
conferred some advantage towards that goal, and hence things
developed that way.

More specific questions of 'why' (such as why does muscle
protein go through constant breakdown and resynthesis,
apparently wasting energy in the process) would have to be
answered wrt: that specific question.

The answer in this case being that it actually provides a
benefit, by making body protein more mobilizable when
necessary. The energy cost of constant protien turnover is
overshadowed by the benefit of being able to get aminos when
they are necessary (by keeping a constantly available pool).

There still doesn't have to be any awareness on the behelf of
the critter for such an adapation to propagate. It simply has
to provide some benefit over another critter.

Lyle Oh yeah, other possible answers to "Why?".
1. Because I said so
2. Why not
3. 42
4. Bork
5. Don't make me turn this car around
6. Which tire? (ok, this is out of place)

[Wayne S. H]

Lyle McDonald wrote:

> "Wayne S. Hill" wrote:
>> Stephen Diamond wrote:
>> > Lyle McDonald wrote:
>> >
>> >> Hmm, maybe that's it, it's a symmetry thing. In
>> >> situations where one 'choice' makes more sense than the
>> >> other, you can posit why and come up with an answer. In
>> >> situations where either choice is equally valid, you
>> >> can't.
>> >
>> > I think that's right. "Why" implies some sort of
>> > selection of means for ends, whether natural or
>> > artificial.
>>
>> I believe "why" implies a cognizant selection.
>
> Cognizant? Speak Englush for the proles, Wayne.
>
> Anyhow, now I think you're being a bit too anthropomorphic
> (and coming from the guy, me, who speaks of hormones
> 'telling' the brain stuff, that' saying something).

Hmm, my point is that I think people who ask why too often are
imposing an anthropomorphic view on the problem at hand. An
awful lot of people consider Nature a consciousness that is
analogous to the human brain. This reflects the tendency of
the human brain to analogize, to the point that this isn't
always such a good idea. People should realize the
shortcomings of their wiring and learn to work around them.

> The basic answer to 'why' in terms of evolutionary selection
> is simply "BEcause it provided some advantage."

Right, but in that case, why ask the question? If the answer
to a biology "why" question is "because it provides an
advantage," you could ask instead, "what advantage does
such-and-such an adaptation confer?" Most such questions are
not fundamentally "why" questions.

> Oh yeah, other possible answers to "Why?".
> 1. Because I said so
> 2. Why not
> 3. 42
> 4. Bork
> 5. Don't make me turn this car around
> 6. Which tire? (ok, this is out of place)

I was with you until #6. Then you lost me, and I got a
headache.

-Wayne

[Stephen Di]

In article <Xns92676ECE81122wshill@130.133.1.4>, "Wayne S.
Hill" <hillw4@asme.org> wrote:

> Stephen Diamond wrote:
>
> > Wayne S. Hill wrote:
> >
> >> A physicist can certainly see that a given biological
> >> adaptation may confer a survival advantage, at least in
> >> certain circumstances, and may see why it does so, but
> >> that does not explain why the adaptation developed. The
> >> best we could hope for is to determine how the adaptation
> >> developed.
> >>
> > Then, do you think the concept of purpose has any
> > relevance to explainging human action?
>
> Now THAT's an interesting question.
>
> > If so, what rubicon has been crossed at _that_ point?
>
> The rubicon that's crossed in consideration of action by
> humans is the assumption of free will (whether real or not).

That would mean that, since I reject free will I am not
entitled to (consistently) ask you a question like, "WHY do
you advocate exercise regime x"?

If one takes a naturalistic approach to human psychology,
THEN the meaning of imputed purposes is pretty much the same
for choice by cognizant subjects as for selection on account
of environmental exigencies. You are entitled to use
different words for the two, but that shouldn't obscure the
fact that we impute purpose to cognizant beings on the same
general kinds of grounds as when evolutionary biologists
explain changes in lineages by selective pressures. I
describe you as acting purposively when your behavior is
adapted to certain the ends that obtain, or which typically
obtain when you engage in that behavior.

These kinds of explanations by purpose are limited by physics,
it must be kept in mind. It might be adaptive if I could
escape an unpleasant situation by jumping to the moon.
Similarly, for any evolutionary change due to natural
selection, you have to ask whether it really was a response to
selective pressure, or a limitation by the very nature of
protoplasm, so to speak.

So, in speculating that humans decondition cardiovascularly
because our ancestors didn't _require_ a way of conditioning
without effort--effort was all too pervasive--the
alternative hypothesis has to be considered: that there just
is no biologically feasible way to maintain conditioning
except by effort.

However, the distinction can in principle be settled
empirically, and in this instance, perhaps not _only_ in
principle. Do animals who hibernate for months on end lose
cardiovascular conditioning? In _their_ case, it _would_ be
maladaptive to lose conditioning because of inactivity. If
bears decondition without exercise during hibernation, then
the reason for human deconditioning with exercise has not to
do with adaptation, but instead with the limitations inherent
in the nature of the circulatory system. (Anyone know anything
about bears?)

Stephen Diamond

[Lyle McDon]

"Wayne S. Hill" wrote:
>
> Lyle McDonald wrote:
>
> > "Wayne S. Hill" wrote:
> >> Stephen Diamond wrote:
> >> > Lyle McDonald wrote:
> >> >
> >> >> Hmm, maybe that's it, it's a symmetry thing. In
> >> >> situations where one 'choice' makes more sense than
> >> >> the other, you can posit why and come up with an
> >> >> answer. In situations where either choice is equally
> >> >> valid, you can't.
> >> >
> >> > I think that's right. "Why" implies some sort of
> >> > selection of means for ends, whether natural or
> >> > artificial.
> >>
> >> I believe "why" implies a cognizant selection.
> >
> > Cognizant? Speak Englush for the proles, Wayne.
> >
> > Anyhow, now I think you're being a bit too anthropomorphic
> > (and coming from the guy, me, who speaks of hormones
> > 'telling' the brain stuff, that' saying something).
>
> Hmm, my point is that I think people who ask why too often
> are imposing an anthropomorphic view on the problem at hand.
> An awful lot of people consider Nature a consciousness that
> is analogous to the human brain.

An awful lot of people are dumb as dirt.

> This reflects the tendency of the human brain to analogize,
> to the point that this isn't always such a good idea. People
> should realize the shortcomings of their wiring and learn to
> work around them.

I don't disagree. I remember hearing it put a little bit
differently in some class many moons ago: the general tendency
to describe the human body/brain as whatever the most
currently advanced technology was. So when the most advanced
technology was basically an assembly line (where one manager
sends messages to other parts of the factory), the body got
described like that. With the advent of the computer, the
analogy changed to that.

> > The basic answer to 'why' in terms of evolutionary
> > selection is simply "BEcause it provided some advantage."
>
> Right, but in that case, why ask the question?

Why ask why? Drink beer.

> If the answer to a biology "why" question is "because it
> provides an advantage," you could ask instead, "what
> advantage does such-and-such an adaptation confer?"

Sure, that's the more relevant (i.e. specific) question since
the general question has pretty much the same general answer.

> Most such questions are not fundamentally "why" questions.

Why?

> > Oh yeah, other possible answers to "Why?".
> > 1. Because I said so
> > 2. Why not
> > 3. 42
> > 4. Bork
> > 5. Don't make me turn this car around
> > 6. Which tire? (ok, this is out of place)
>
> I was with you until #6. Then you lost me, and I got a
> headache.

It was an obtuse reference even for me. It's one of those
internet jokes/urban legends that floats around all the time,
about two guys who go out partying the weekend before an exam,
wake up late, miss the exam, tell the professor that they got
a flat tire and that's why they missed it, ask for a makeup
exame. Given make up exams in separate rooms.

First question is trivial regarding the course, 5 points.

Second question is worth 95 points

"Which tire?"

Lyle

[Wayne S. H]

Lyle McDonald wrote:

> "Wayne S. Hill" wrote:
>>
>> Hmm, my point is that I think people who ask why too often
>> are imposing an anthropomorphic view on the problem at
>> hand. An awful lot of people consider Nature a
>> consciousness that is analogous to the human brain.
>
> An awful lot of people are dumb as dirt.

Sig material.

>> This reflects the tendency of the human brain to analogize,
>> to the point that this isn't always such a good idea.
>> People should realize the shortcomings of their wiring and
>> learn to work around them.
>
> I don't disagree. I remember hearing it put a little bit
> differently in some class many moons ago: the general
> tendency to describe the human body/brain as whatever the
> most currently advanced technology was. So when the most
> advanced technology was basically an assembly line (where
> one manager sends messages to other parts of the factory),
> the body got described like that. With the advent of the
> computer, the analogy changed to that.

That makes sense. People also carry cyclical views of the
world around with them, because of the cycles of the clock,
week (which is totally made up), lunar cycle, and seasons. A
lot of people seem to think that events follow cycles, as if
the universe were this tremendously complicated set of gears
that make just about everything come around every now and
again. Oh, I see that Friday the 13th falls on a Tuesday
this month.

>> > 6. Which tire? (ok, this is out of place)
>>
>> I was with you until #6. Then you lost me, and I got a
>> headache.
>
> It was an obtuse reference even for me. It's one of those
> internet jokes/urban legends that floats around all the
> time, about two guys who go out partying the weekend before
> an exam, wake up late, miss the exam, tell the professor
> that they got a flat tire and that's why they missed it, ask
> for a makeup exame. Given make up exams in separate rooms.
>
> First question is trivial regarding the course, 5 points.
>
> Second question is worth 95 points
>
> "Which tire?"

Ah. Clarity washes over me.

-Wayne "An awful lot of people are dumb as dirt." - Lyle
McDonald

[Lyle McDon]

"Wayne S. Hill" wrote:
>
> Lyle McDonald wrote:
>
> > "Wayne S. Hill" wrote:
> >>
> >> Hmm, my point is that I think people who ask why too
> >> often are imposing an anthropomorphic view on the problem
> >> at hand. An awful lot of people consider Nature a
> >> consciousness that is analogous to the human brain.
> >
> > An awful lot of people are dumb as dirt.
>
> Sig material.

You should use the full Lyle-ism.

Most people are dumb as dirt. Many people are dumber
than that.

> That makes sense. People also carry cyclical views of the
> world around with them, because of the cycles of the clock,
> week (which is totally made up), lunar cycle, and seasons.
> A lot of people seem to think that events follow cycles, as
> if the universe were this tremendously complicated set of
> gears that make just about everything come around every now
> and again.

Oh, but it is, set in place by a creator billions of
years ago.

> Oh, I see that Friday the 13th falls on a Tuesday this
> month.

Trying to explain that our time choices are arbitrary to
people always draws funny stares.

Lyle

[Wayne S. H]

Stephen Diamond wrote:

> Wayne S. Hill wrote:
>> Stephen Diamond wrote:
>> > Wayne S. Hill wrote:
>> >
>> >> A physicist can certainly see that a given biological
>> >> adaptation may confer a survival advantage, at least in
>> >> certain circumstances, and may see why it does so, but
>> >> that does not explain why the adaptation developed. The
>> >> best we could hope for is to determine how the
>> >> adaptation developed.
>> >>
>> > Then, do you think the concept of purpose has any
>> > relevance to explainging human action?
>>
>> Now THAT's an interesting question.
>>
>> > If so, what rubicon has been crossed at _that_ point?
>>
>> The rubicon that's crossed in consideration of action
>> by humans is the assumption of free will (whether real
>> or not).
>
> That would mean that, since I reject free will I am not
> entitled to (consistently) ask you a question like, "WHY do
> you advocate exercise regime x"?

If you reject free will (i.e., nondeterminism), the nature of
all questions is irrelevant, because all of what happens
(including the questions) happens because it must.

> If one takes a naturalistic approach to human psychology,
> THEN the meaning of imputed purposes is pretty much the same
> for choice by cognizant subjects as for selection on account
> of environmental exigencies. You are entitled to use
> different words for the two, but that shouldn't obscure the
> fact that we impute purpose to cognizant beings on the same
> general kinds of grounds as when evolutionary biologists
> explain changes in lineages by selective pressures.

But the point is that, when evolutionary biologists use "why"
to ask those questions, it's a brain-pun: the question is
equivalent to a different "how" question, yet their
anthropomorphic view of the subject causes them to use
different words. The biologists have no particular reason to
impute purpose to evolution.

> So, in speculating that humans decondition cardiovascularly
> because our ancestors didn't _require_ a way of conditioning
> without effort--effort was all too pervasive--the
> alternative hypothesis has to be considered: that there just
> is no biologically feasible way to maintain conditioning
> except by effort.

Hey, no fair getting back on-topic!

-Wayne

[Lyle McDon]

Stephen Diamond wrote:

> However, the distinction can in principle be settled
> empirically, and in this instance, perhaps not _only_ in
> principle. Do animals who hibernate for months on end lose
> cardiovascular conditioning?

I have no idea, but they spare protein like crazy. They
actually lose zero LBM during hibernation. One of a few
animals that adapted to doing so (King Penguin is another, and
there's a third that I forget).

> In _their_ case, it _would_ be maladaptive to lose
> conditioning because of inactivity.

Why?

> If bears decondition without exercise during hibernation,
> then the reason for human deconditioning with exercise has
> not to do with adaptation, but instead with the limitations
> inherent in the nature of the circulatory system.

I don't see how this follows. I still think that the
'simplest' explanation why we decondition is simply an issue
of energy saving. Many tissues in the body are plastic (i.e.
adaptable to stimuli) although there are a few exceptions (and
the sytems that aaren't adaptable typically have a huge error
margin in so that we rarely tax them to their limits). Our
bodies have a finite store of energy to expend and thigns
frequently come down to a situation of compromises and
limitations.

A really good example is fetal development under conditions of
severe malnutrition. Under those situations, development of
certain parts of the body is typically compromised in favor of
other, more important ones (oh yeah, it looks like mom's
leptin levels are one of the signals, since I have to tie
everything into that). For example, limb defects are common,
brain defects less so. Why? BEcause, from a strict survival
standpoint, the brain is required, limbs are not (technically
speaking). So under a situation of limited resources, the body
adapts accordingly, developing only those systems which are
required for immediate survival.

I really think it's a similar deal here. Our bodies don't seem
particularly concerned with long-term end results (i.e. that
you might be at greater cardiac risk 50 years down the road is
of no important relative to what your body does to dispose of
cholesterol right now).

A crappy analogy might be one where you have limited financial
resources. Why would you continue paying money for something
that you're not currently using, when you have limitations?
That is, why expend the resources on something that has no
immediate short-term benefit?

If the body has no reason (reason here = stimuli that is
imposing a demand that 'tells' the system to adapt) to
maintain an adaptation, why would it continue to expend energy
maintaining it? That would be maladaptive.

>(Anyone know anything about bears?)

I wanna be a bear - Descendents

Lyle

[Keith Hobm]

In article <3D593651.B97D5460@onr.com>, lylemcd@onr.com wrote:

>
> >(Anyone know anything about bears?)
>
> I wanna be a bear - Descendents

We used to always say, "If you're gonna be a bear, might as
well be a grizzly."

--
Keith Hobman

You can put your boots in the oven, but that doesn't make
them biscuits.

[Lyle McDon]

"Wayne S. Hill" wrote:
>
> Stephen Diamond wrote:
>
> > Wayne S. Hill wrote:
> >> Stephen Diamond wrote:
> >> > Wayne S. Hill wrote:
> >> >
> >> >> A physicist can certainly see that a given biological
> >> >> adaptation may confer a survival advantage, at least
> >> >> in certain circumstances, and may see why it does so,
> >> >> but that does not explain why the adaptation
> >> >> developed. The best we could hope for is to determine
> >> >> how the adaptation developed.
> >> >>
> >> > Then, do you think the concept of purpose has any
> >> > relevance to explainging human action?
> >>
> >> Now THAT's an interesting question.
> >>
> >> > If so, what rubicon has been crossed at _that_ point?
> >>
> >> The rubicon that's crossed in consideration of action by
> >> humans is the assumption of free will (whether real or
> >> not).
> >
> > That would mean that, since I reject free will I am not
> > entitled to (consistently) ask you a question like, "WHY
> > do you advocate exercise regime x"?
>
> If you reject free will (i.e., nondeterminism), the nature
> of all questions is irrelevant, because all of what happens
> (including the questions) happens because it must.

You were destined to say that, just so you know.

>
> > If one takes a naturalistic approach to human psychology,
> > THEN the meaning of imputed purposes is pretty much the
> > same for choice by cognizant subjects as for selection on
> > account of environmental exigencies. You are entitled to
> > use different words for the two, but that shouldn't
> > obscure the fact that we impute purpose to cognizant
> > beings on the same general kinds of grounds as when
> > evolutionary biologists explain changes in lineages by
> > selective pressures.
>
> But the point is that, when evolutionary biologists use
> "why" to ask those questions, it's a brain-pun: the question
> is equivalent to a different "how" question, yet their
> anthropomorphic view of the subject causes them to use
> different words. The biologists have no particular reason to
> impute purpose to evolution.

Impute is a funny sounding word.

But I still see a distinction between 'why' and 'how'
questions.

How, to me, implies the mechanism. That is, our muscle adapt
to cardiovascular training via gene induction that leads to
adapation 1,2,3. That's how we adapt.

In response to deconditioning, those same genes turn off (and
others turn on) which cause a series of deadaptations. That's
how we de-adapt.

A far different cry from 'why' we adapt/de-adapt (i.e. what
evolutionary purpose did it serve for the system to work
that way).

> > So, in speculating that humans decondition
> > cardiovascularly because our ancestors didn't _require_ a
> > way of conditioning without effort--effort was all too
> > pervasive--the alternative hypothesis has to be
> > considered: that there just is no biologically feasible
> > way to maintain conditioning except by effort.
>
> Hey, no fair getting back on-topic!

Yeah, this is mfw after all. Keep it misc, or take it to
another board.

Anyway, as far as 'biologically feasible ways to maintain
conditioning', I disagree with the above statement. There was
some drug compound talked about a while ago that sends the
biochemical signal to muscles telling it to adapt aerobically.
Taht would be one way to maintain conditioning without effort,
by artificially sending the same biochemical signals that
'tell' the system to adapt.

For example, if you inject an IGF-1 adenovirus (that rewrites
the DNA code such that hte muscle overexpresses mechano-growth
factor) into a muscle, it will grow without any imposed
demand. Why? Because you have sent the same 'signal' to the
muscle that would normally be sent by training. I want some of
that for my biceps.

Lyle

[Wayne S. H]

Lyle McDonald wrote:

> "Wayne S. Hill" wrote:
>>
>> If you reject free will (i.e., nondeterminism), the nature
>> of all questions is irrelevant, because all of what happens
>> (including the questions) happens because it must.
>
> You were destined to say that, just so you know.

See? He does get it.

-Wayne

[Stephen Di]

In article <3D593651.B97D5460@onr.com>, Lyle McDonald
<lylemcd@onr.com> wrote:

> Stephen Diamond wrote:
>
> > However, the distinction can in principle be settled
> > empirically, and in this instance, perhaps not _only_ in
> > principle. Do animals who hibernate for months on end lose
> > cardiovascular conditioning?
>
> I have no idea, but they spare protein like crazy. They
> actually lose zero LBM during hibernation. One of a few
> animals that adapted to doing so (King Penguin is another,
> and there's a third that I forget).
>
> > In _their_ case, it _would_ be maladaptive to lose
> > conditioning because of inactivity.
>
> Why?

If I am right that it was NOT maladaptive for human dependence
on exercise to maintain fitness on account of the high
activity level of our ancestors, then an animal which could
ONLY maintain its fitness over time by naturally retaining it
during long periods of activity would not show exercise
dependence for fitness.
>

> I don't see how this follows. I still think that the
> 'simplest' explanation why we decondition is simply an issue
> of energy saving. Many tissues in the body are plastic (i.e.
> adaptable to stimuli) although there are a few exceptions
> (and the sytems that aaren't adaptable typically have a huge
> error margin in so that we rarely tax them to their limits).
> Our bodies have a finite store of energy to expend and
> thigns frequently come down to a situation of compromises
> and limitations.
>
> A really good example is fetal development under conditions
> of severe malnutrition. Under those situations, development
> of certain parts of the body is typically compromised in
> favor of other, more important ones (oh yeah, it looks like
> mom's leptin levels are one of the signals, since I have to
> tie everything into that). For example, limb defects are
> common, brain defects less so. Why? BEcause, from a strict
> survival standpoint, the brain is required, limbs are not
> (technically speaking). So under a situation of limited
> resources, the body adapts accordingly, developing only
> those systems which are required for immediate survival.
>
> I really think it's a similar deal here. Our bodies don't
> seem particularly concerned with long-term end results (i.e.
> that you might be at greater cardiac risk 50 years down the
> road is of no important relative to what your body does to
> dispose of cholesterol right now).
>
> A crappy analogy might be one where you have limited
> financial resources. Why would you continue paying money for
> something that you're not currently using, when you have
> limitations? That is, why expend the resources on something
> that has no immediate short-term benefit?
>
> If the body has no reason (reason here = stimuli that is
> imposing a demand that 'tells' the system to adapt) to
> maintain an adaptation, why would it continue to expend
> energy maintaining it? That would be maladaptive.
>
An assumption of this discussion has been that cardiovascular
fitness in and of itself, unlike skeletal muscular fitness,
does not consume resources (except for consumption imposed by
exercise). If that assumption is false, then your explanation
is probably right. Skeletal muscular fitness is associated
with a greater caloric requirement and with greater bulk to
lug around. If there are resource sufficiency issues in
cardiovascular fitness, no one in this discussion has said
what they might be.

Stephen Diamond

[Stephen Di]

In article <Xns92695757F7D20wshill@130.133.1.4>, "Wayne S.
Hill" <hillw4@asme.org> wrote:

> Stephen Diamond wrote:
>
> > Wayne S. Hill wrote:
> >> Stephen Diamond wrote:
> >> > Wayne S. Hill wrote:
> >> >
> >> >> A physicist can certainly see that a given biological
> >> >> adaptation may confer a survival advantage, at least
> >> >> in certain circumstances, and may see why it does so,
> >> >> but that does not explain why the adaptation
> >> >> developed. The best we could hope for is to determine
> >> >> how the adaptation developed.
> >> >>
> >> > Then, do you think the concept of purpose has any
> >> > relevance to explainging human action?
> >>
> >> Now THAT's an interesting question.
> >>
> >> > If so, what rubicon has been crossed at _that_ point?
> >>
> >> The rubicon that's crossed in consideration of action by
> >> humans is the assumption of free will (whether real or
> >> not).
> >
> > That would mean that, since I reject free will I am not
> > entitled to (consistently) ask you a question like, "WHY
> > do you advocate exercise regime x"?
>
> If you reject free will (i.e., nondeterminism), the nature
> of all questions is irrelevant, because all of what happens
> (including the questions) happens because it must.

Why does the fact that the answer you provide to my question
is determined (as is my asking it) contradict, say, the fact
that your answer is likely to supply correct information,
which serves, in purely deterministic fashion, to cause me to
ask the question?

------

I think we have probably clarified why we disagree.

It really isn't that I attribute an actual property
(purposiveness) to nature whereas you don't, but that you
attribute a property (which can also be termed
'purposiveness') to human beings, whereas I don't. In a purely
naturalistic account of human behavior, human purpose and the
selectivity inherent in the "struggle of existence" are very
much alike. But, if you think human purposiveness has a
libertarian nature (that is, consists of free will--not the
political sense of 'libertarian,' although most, but not all,
political libertarians do believe in and emphasize the
existence of free will), then calling selection purposive will
carry the implication that it is governed by genuine teleology
(as libertarians believe is true of the will), hence
antropomorphic.

Whether correct or not in their naturalism, I would submit
that most evolutionary biologists think of purposiveness in
nature as algorithmic, not teleological. Your real quarrel is
not with them over natural purposiveness, but with
materialists (including most evolutionary biologists . . . and
me) with regard to the naturalization of human purposiveness.
We think human behavior is algorithmic too.

Stephen Diamond

[Wayne S. H]

Stephen Diamond wrote:

> I think we have probably clarified why we disagree.

Ah, but do we? I never said I didn't believe in determinism.
But if there is a clockwork determinism, then asking "why" is
moot: the real answer to "why" is always "because".

-Wayne

[Lyle McDon]

Stephen Diamond wrote:
>
> In article <3D593651.B97D5460@onr.com>, Lyle McDonald
> <lylemcd@onr.com> wrote:
>
> > Stephen Diamond wrote:
> >
> > > However, the distinction can in principle be settled
> > > empirically, and in this instance, perhaps not _only_ in
> > > principle. Do animals who hibernate for months on end
> > > lose cardiovascular conditioning?
> >
> > I have no idea, but they spare protein like crazy. They
> > actually lose zero LBM during hibernation. One of a few
> > animals that adapted to doing so (King Penguin is another,
> > and there's a third that I forget).
> >
> > > In _their_ case, it _would_ be maladaptive to lose
> > > conditioning because of inactivity.
> >
> > Why?
>
> If I am right that it was NOT maladaptive for human
> dependence on exercise to maintain fitness on account of the
> high activity level of our ancestors,

I can't work my way through this double negative and figure
out what you're saying. But see below, I've got an entirely
different hypothesis.

> then an animal which could ONLY maintain its fitness over
> time by naturally retaining it during long periods of
> activity would not show exercise dependence for fitness.

Can't figure out what you're saying here either. Either you're
being obtuse or I'm just being dense today.

> > If the body has no reason (reason here = stimuli that is
> > imposing a demand that 'tells' the system to adapt) to
> > maintain an adaptation, why would it continue to expend
> > energy maintaining it? That would be maladaptive.
> >
> An assumption of this discussion has been that
> cardiovascular fitness in and of itself, unlike skeletal
> muscular fitness, does not consume resources (except for
> consumption imposed by exercise). If that assumption is
> false, then your explanation is probably right. Skeletal
> muscular fitness is associated with a greater caloric
> requirement and with greater bulk to lug around. If there
> are resource sufficiency issues in cardiovascular fitness,
> no one in this discussion has said what they might be.

Some energetically costly adaptations that jump to mind
increased mitochondrial biogenesis enzymes invovled in aerobic
adapations increased blood supply (capillaries) requiring
angiogenesis increased hemoglobin synthesis others

None of it may be particularly costly on the whole body level,
but on an individual cellular level (which is how the cells
are going to look at
it), it's all energy taht could be otherwise spent on
something else.

And with that said, in thikning about this more, I think we
may be looking at this incorrectly, too narrowly. That is,
we've posed the wrong question. It may have absolutely
nothing to do with the body maintaining (or not) aerobic/CV
fitness per se.

Rather, it occurs to me that one of the absolute hallmarks of
humans (as opposed to most other critters) is simply
adaptability per se. That is, most animals are fairly locked
into a given niche. They are specialists
(i.u. cheetahs run fast, frogs are pretty close the best
jumpers if you're looking at a single or a few jumps,
some animals are built to handle cold, others heat,
etc.). But they are fairly unadaptable in the big scheme
of things. Take any given animal outside of its specific
niche and it's dead meat (figuratively speaking). Put a
polar bear in a hot environment, and it's dead; put a
camel in a cold one and it's the same thing.

Humans, on the other hand, are probably the most flexible (in
terms of ability to adapt to different to the widest range of
stimuli) of all. Of course, the tradeoff is that we aren't as
good at any one thing as any of the animals who are
specialized (one exception springs to mind, bad pun intended).
With the exceptions of the real extremes (hard vacuum,
underwater, extreme protracted cold), humans can adapt to
pretty much anything. That's why we've been able to thrive all
over the planet, in environs from one extreme to the other.

But being able to do that requires a lot of flexibility and a
lot of adapatiblity. IMplicit in that, is the ability to
de-adapt as well. Why? Because if you adapt to something and
that change becomes permanent, you can't very well adapt to a
different stimuli. That is, say you're in an environment which
requires high levels of CV fitness. Fine, you adapt over time.
But now you get moved into an environment that requires high
strength fitness for survival. If your muscles, heart, etc.
are 'locked into' cardiovascular adaptations, you wouldn't be
able to adapt. To survive in teh new environment requires not
only that you re-adapt to the new stimuli, but de-adapt to the
old one (esp. considering that the adapations are essentially
at opposite extremes in terms of energetics, etc.).

It may simply be that remaining flexible/adaptable imposed the
need to be able to not only adapt to stimuli, but also to
de-adapt to the lack of that same stimuli. An outcome of that
would be a loss of fitness in response to a lack of stimuli.

That is, it may not be that gaining/losing CV fitness was
adaptive/maladaptive per se, except inasmuch as it represented
an ability to adapt/de-adapt in general. That is, for most
things, humans show a generalized ability to adapt to a given
stimuli and de-adapt to a loss of that stimuli (or re-adapt to
a new stimuli). It's one of the hallmarks of our flexibility.
The outcome being loss of adaptation in the absence of stimuli
in general (the specific adaptation being irrelevant).

of course, the exception, the one place where we did
specialize realative to most animals is in brainpower (hence
the pun above). And tha'ts one of the places that you don't
see the same type of adaptability/deadaptability. Especially
de-adaptability. A lot of brain changes which occur are
essentially imprinted/irreversible. Which would follow the
above argument. Specialization would seem to require a sort
of irreversibility of adaptations; flexibility/generalization
the opposite.

Or I still just need a nap.

Lyle

[Robert Dor]

On Wed, 14 Aug 2002 00:15:12 GMT, Lyle McDonald
<lylemcd@onr.com> wrote:

>Stephen Diamond wrote:
>>
>> In article <3D593651.B97D5460@onr.com>, Lyle McDonald
>> <lylemcd@onr.com> wrote:
>>
>> > Stephen Diamond wrote:
>> >
>> > > However, the distinction can in principle be settled
>> > > empirically, and in this instance, perhaps not _only_
>> > > in principle. Do animals who hibernate for months on
>> > > end lose cardiovascular conditioning?
>> >
>> > I have no idea, but they spare protein like crazy. They
>> > actually lose zero LBM during hibernation. One of a few
>> > animals that adapted to doing so (King Penguin is
>> > another, and there's a third that I forget).
>> >
>> > > In _their_ case, it _would_ be maladaptive to lose
>> > > conditioning because of inactivity.
>> >
>> > Why?
>>
>> If I am right that it was NOT maladaptive for human
>> dependence on exercise to maintain fitness on account of
>> the high activity level of our ancestors,

>I can't work my way through this double negative and figure
>out what you're saying.

Mongo Translator say:

"Me think that historically it not problem that human need
exercise to not be so fat and flabby, because human ancestors
always run and play. That why they stay fit and not be fat
and flabby."

>But see below, I've got an entirely different hypothesis.
>
>> then an animal which could ONLY maintain its fitness over
>> time by naturally retaining it during long periods of
>> activity would not show exercise dependence for fitness.
>
>Can't figure out what you're saying here either. Either
>you're being obtuse or I'm just being dense today.

Mongo Translator say:

"If that am true, then maybe big animal that must spend long
time without exercising (like sleepy bear in cave) would have
to be able stay fit even if never exercise. Animal like that
would never need exercise."

<snip

[Lyle McDon]

"Wayne S. Hill" wrote:
>
> Lyle McDonald wrote:
>
> > "Wayne S. Hill" wrote:
> >>
> >> If you reject free will (i.e., nondeterminism), the
> >> nature of all questions is irrelevant, because all of
> >> what happens (including the questions) happens because it
> >> must.
> >
> > You were destined to say that, just so you know.
>
> See? He does get it.

My equation said you'd say that next.

Lyle and that I'd say this, of course and that and this and
that and this goto 10

[Lee Michae]

"Robert Dorf" <robertdorf@japan.com> wrote in message
news:dgijluoec6kpaaugihgh6jc4leut75c3b5@4ax.com...
> On Wed, 14 Aug 2002 00:15:12 GMT, Lyle McDonald
> <lylemcd@onr.com> wrote:
>
> >Stephen Diamond wrote:
> >>
> >> In article <3D593651.B97D5460@onr.com>, Lyle McDonald
> >> <lylemcd@onr.com> wrote:
> >>
> >> > Stephen Diamond wrote:
> >> >
> >> > > However, the distinction can in principle be settled
> >> > > empirically,
and in
> >> > > this instance, perhaps not _only_ in principle. Do
> >> > > animals who
hibernate
> >> > > for months on end lose cardiovascular conditioning?
> >> >
> >> > I have no idea, but they spare protein like crazy. They
> >> > actually
lose
> >> > zero LBM during hibernation. One of a few animals that
> >> > adapted to
doing
> >> > so (King Penguin is another, and there's a third that I
> >> > forget).
> >> >
> >> > > In _their_ case, it _would_ be maladaptive to lose
> >> > > conditioning because of inactivity.
> >> >
> >> > Why?
> >>
> >> If I am right that it was NOT maladaptive for human
> >> dependence on exercise to maintain fitness on account of
> >> the high activity level of our ancestors,
>
> >I can't work my way through this double negative and figure
> >out what you're saying.
>
> Mongo Translator say:
>
> "Me think that historically it not problem that human need
> exercise to not be so fat and flabby, because human
> ancestors always run and play. That why they stay fit and
> not be fat and flabby."
>
>
> >But see below, I've got an entirely different hypothesis.
> >
> >> then an animal which could ONLY maintain its fitness over
> >> time by naturally retaining it during long periods of
> >> activity would
not
> >> show exercise dependence for fitness.
> >
> >Can't figure out what you're saying here either. Either
> >you're being obtuse or I'm just being dense today.
>
> Mongo Translator say:
>
> "If that am true, then maybe big animal that must spend long
> time without exercising (like sleepy bear in cave) would
> have to be able stay fit even if never exercise. Animal like
> that would never need exercise."
>
> <snip>

Mongo Translator say:

"Big animal (like sleepy bear in cave) like Robert Dorf. Wants
to exercise him in cave, then maybe eat him afterwards."

[Stephen Di]

In article <Xns9269BDF9154BBwshill@130.133.1.4>, "Wayne S.
Hill" <hillw4@asme.org> wrote:

> Stephen Diamond wrote:
>
> > I think we have probably clarified why we disagree.
>
> Ah, but do we? I never said I didn't believe in determinism.

I had thought you said that without free will even asking the
question is meaningless. I took that to be a reductio ad
absurdum of determinism.

But
> if there is a clockwork determinism, then asking "why" is
> moot: the real answer to "why" is always "because".

OK, that is I think a matter of terminological taste, as
long as you find a way to distinguish two KINDS of 'because'
questions: one for mechanistic explanation, the other for
explanation by some selective process, or in other terms,
one for the structures causing the phenomenon and the other,
for only certain phenomena, what function the structures
serve. It is the difference between asking how a biological
process takes place and asking how it evolved. There is
probably only an advantage to considering the latter how
question a why question too if you think the question of why
a person does something, when the question is about motive,
has an answer of the same _sort_ as the question of how a
biological trait evolved.

Stephen Diamond

[Stephen Di]

In article <3D599E9D.A2F268AB@onr.com>, Lyle McDonald
<lylemcd@onr.com> wrote:

> I can't work my way through this double negative and figure
> out what you're saying. But see below, I've got an entirely
> different hypothesis.

See Robert Dorf's translation.

It isn't _exactly_ a double negative: to say it is not
maladaptive is not quive equivalent to saying it is adaptive.
>
> > then an animal which could ONLY maintain its fitness over
> > time by naturally retaining it during long periods of
> > activity would not show exercise dependence for fitness.
>
> Can't figure out what you're saying here either. Either
> you're being obtuse or I'm just being dense today.

Robert Dorf was kind enough to provide a translation.

> None of it may be particularly costly on the whole body
> level, but on an individual cellular level (which is how the
> cells are going to look at
> it), it's all energy taht could be otherwise spent on
> something else.

The cell may be the basic physiological unit of analysis, but
it isn't the right evolutionary unit. What the cells is
selected for doing depends on the survival of the organism (or
more exactly, of its genes).
>
> And with that said, in thikning about this more, I think we
> may be looking at this incorrectly, too narrowly. That is,
> we've posed the wrong question. It may have absolutely
> nothing to do with the body maintaining (or not) aerobic/CV
> fitness per se.
>
> Rather, it occurs to me that one of the absolute hallmarks
> of humans (as opposed to most other critters) is simply
> adaptability per se. That is, most animals are fairly locked
> into a given niche. They are specialists
> (i.e. cheetahs run fast, frogs are pretty close the best
> jumpers if you're looking at a single or a few jumps,
> some animals are built to handle cold, others heat,
> etc.). But they are fairly unadaptable in the big
> scheme of things. Take any given animal outside of its
> specific niche and it's dead meat (figuratively
> speaking). Put a polar bear in a hot environment, and
> it's dead; put a camel in a cold one and it's the same
> thing.
>
> Humans, on the other hand, are probably the most flexible
> (in terms of ability to adapt to different to the widest
> range of stimuli) of all. Of course, the tradeoff is that we
> aren't as good at any one thing as any of the animals who
> are specialized (one exception springs to mind, bad pun
> intended). With the exceptions of the real extremes (hard
> vacuum, underwater, extreme protracted cold), humans can
> adapt to pretty much anything. That's why we've been able to
> thrive all over the planet, in environs from one extreme to
> the other.
>
> But being able to do that requires a lot of flexibility and
> a lot of adapatiblity. IMplicit in that, is the ability to
> de-adapt as well. Why? Because if you adapt to something and
> that change becomes permanent, you can't very well adapt to
> a different stimuli. That is, say you're in an environment
> which requires high levels of CV fitness. Fine, you adapt
> over time. But now you get moved into an environment that
> requires high strength fitness for survival. If your
> muscles, heart, etc. are 'locked into' cardiovascular
> adaptations, you wouldn't be able to adapt. To survive in
> teh new environment requires not only that you re-adapt to
> the new stimuli, but de-adapt to the old one (esp.
> considering that the adapations are essentially at opposite
> extremes in terms of energetics, etc.).

This may be true, but I don't think the evidence supports it.
Someone more knowledgeable than I should comment, but as far
as I know, CV fitness has no significant drawbacks. If it
does, I think a lot of people would like to know what they
are. The conventional wisdom is that it is an unalloyed
blessing, beneficial even to performance in purely cerbral
activities. If what you are saying were true, there would be
athletic performances for which it would be _preferable_ NOT
to have CV fitness (just as there are performances involving
certain skeletal muscle groups that are worsened by excessive
musuclar hypertrophy in other parts of the body, because of
the added weight, etc.

Also, if loss of fitness in humans was part of a specifically
human adaptational template, other mammals would NOT lose
fitness with activity. The ones I have known do. But, I
haven't known any bears.
>

<snippage throughout for concision>

Stephen Diamond

[Robert Dor]

On Thu, 15 Aug 2002 15:24:15 -0700, Stephen Diamond
<stephend15@mindspring.com> wrote:

>In article
><stephend15-1A8791.15105915082002@news.mindspring.com>,
>Stephen Diamond <stephend15@mindspring.com> wrote:
>
>> In article <9ncolus8omh7kdvnp1rtia2063rv13j1ok@4ax.com>,
>> Robert Dorf <robertdorf@japan.com> wrote:
>>
>> > On Thu, 15 Aug 2002 19:23:51 GMT, Lyle McDonald
>> > <lylemcd@onr.com> wrote:
>> >
>> > >Stephen Diamond wrote:
>> > >>
>> > <snip>
>> > >> See Robert Dorf's translation.
>> > >
>> > >It still made zero sense to me.
>> > >
>> > <snip>
>> >
>> > I'll take one more (non-jokey and probably futile) shot
>> > at it.
>> >
>> > Stephen D Posted:
>> >
>> > >>> If I am right that it was NOT maladaptive for human
>> > >>> dependence on exercise to maintain fitness on account
>> > >>> of the high activity level our ancestors, then an
>> > >>> animal which could ONLY maintain its fitness over
>> > >>> time by naturally retaining it during long periods of
>> > >>> activity would not show exercise dependence for
>> > >>> fitness.
>> >
>> > It looks like a faulty if / then statement to me. It
>> > might parse as; "If I'm right and human dependence on
>> > exercise for fitness was not a problem for our ancestors
>> > thanks to their high activity levels, then an animal
>> > which had to maintain its fitness despite long periods of
>> > inactivity would not need to exercise in order to remain
>> > fit."
>> >
>> > The statement remains incorrect, as (a) does not in fact
>> > necessitate
>> > (b). Also note that I changed the second usage of
>> > "activity" to "inactivity", which is what I think
>> > that Stephen meant.
>> >
>> >
>>
>> In the summary above, some premises are only implied. Let
>> me put it more explicitly:
>>
>> ***If our ancesters did not evolve mechanisms to maintain
>> fitness through inactivity because of their inevitably high
>> activity level, then organisms that naturally go through
>> long periods of inactivity would probably have evolved such
>> mechanisms. ***
>>
>
>The only important difference between the earlier version,
>which you correctly parsed, and the above is that probability
>replaces necessity.
>

I would agree that it seems likely that, if mammals (including
humans) needed to maintain a base level of fitness despite
extended periods of inactivity, then they would evolve
mechanisms for doing so. However, the If-Then aspect of the
statement that "If our ancestors did not evolve mechanisms to
maintain fitness through inactivity because of their
inevitably high activity level, then organisms that naturally
go through long periods of inactivity would probably have
evolved such mechanisms" remains incorrect. (A) Our ancestors,
possibly not needing such mechanisms, may not have evolved
them. And yes, (B) "organisms that naturally go through long
periods of inactivity would probably have evolved such
mechanisms" may be correct. However, there is no causal
If-Then relationship between A and B as you've phrased your
statement. A more correct form for the statement might be "If
mammals that naturally went through long periods of inactivity
would have evolved mechanisms that allowed them to maintain a
base level of fitness despite said inactivity, then perhaps
humans did not evolve such mechanisms because they did not
naturally go through long periods of inactivity."

This may be the least comprehensible thing I've ever posted to
MFW. Considering my posting history, I find that a bit
disturbing. ;-)

>If you think it still doesn't follow, why not? What likely
>scenario are you envisioning in which
>
>1. Provided that humans needed to remain fit despite
> inactivity, they _would_ have evolved mechanisms to
> accomplish it. (The hypothesis under scrutiny) and
>2. Other *mammals* (what I really should have written,
> instead of "organisms") that would substantially benefit
> from remaining fit despite inactivity FAIL to develop such
> mechanisms.
>
>I can think of scenarios (mostly having to do with path
>dependence in evolution), but not probable scenarios.
>
>Stephen Diamond

[Robert Dor]

On Thu, 15 Aug 2002 19:04:56 GMT, Lyle McDonald
<lylemcd@onr.com> wrote:

>Robert Dorf wrote:
>>
>> On Wed, 14 Aug 2002 00:15:12 GMT, Lyle McDonald
>> <lylemcd@onr.com> wrote:
>>
>> >Stephen Diamond wrote:
>> >>
>> >> In article <3D593651.B97D5460@onr.com>, Lyle McDonald
>> >> <lylemcd@onr.com> wrote:
>> >>
>> >> > Stephen Diamond wrote:
>> >> >
>> >> > > However, the distinction can in principle be settled
>> >> > > empirically, and in this instance, perhaps not
>> >> > > _only_ in principle. Do animals who hibernate for
>> >> > > months on end lose cardiovascular conditioning?
>> >> >
>> >> > I have no idea, but they spare protein like crazy.
>> >> > They actually lose zero LBM during hibernation. One of
>> >> > a few animals that adapted to doing so (King Penguin
>> >> > is another, and there's a third that I forget).
>> >> >
>> >> > > In _their_ case, it _would_ be maladaptive to lose
>> >> > > conditioning because of inactivity.
>> >> >
>> >> > Why?
>> >>
>> >> If I am right that it was NOT maladaptive for human
>> >> dependence on exercise to maintain fitness on account of
>> >> the high activity level of our ancestors,
>>
>> >I can't work my way through this double negative and
>> >figure out what you're saying.
>>
>> Mongo Translator say:
>>
>> "Me think that historically it not problem that human need
>> exercise to not be so fat and flabby, because human
>> ancestors always run and play. That why they stay fit and
>> not be fat and flabby."
>>
>> >But see below, I've got an entirely different hypothesis.
>> >
>> >> then an animal which could ONLY maintain its fitness
>> >> over time by naturally retaining it during long periods
>> >> of activity would not show exercise dependence for
>> >> fitness.
>> >
>> >Can't figure out what you're saying here either. Either
>> >you're being obtuse or I'm just being dense today.
>>
>> Mongo Translator say:
>>
>> "If that am true, then maybe big animal that must spend
>> long time without exercising (like sleepy bear in cave)
>> would have to be able stay fit even if never exercise.
>> Animal like that would never need exercise."
>
>I miss John Carlo's clarity and erudition.
>
>Lyle

He was an interesting fellow.

[Robert Dor]

On Thu, 15 Aug 2002 19:23:51 GMT, Lyle McDonald
<lylemcd@onr.com> wrote:

>Stephen Diamond wrote:
>>
<snip>
>> See Robert Dorf's translation.
>
>It still made zero sense to me.
>
<snip>

I'll take one more (non-jokey and probably futile) shot at it.

Stephen D Posted:

>>> If I am right that it was NOT maladaptive for human
>>> dependence on exercise to maintain fitness on account of
>>> the high activity level our ancestors, then an animal
>>> which could ONLY maintain its fitness over time by
>>> naturally retaining it during long periods of activity
>>> would not show exercise dependence for fitness.

It looks like a faulty if / then statement to me. It might
parse as; "If I'm right and human dependence on exercise for
fitness was not a problem for our ancestors thanks to their
high activity levels, then an animal which had to maintain its
fitness despite long periods of inactivity would not need to
exercise in order to remain fit."

The statement remains incorrect, as (a) does not in fact
necessitate
(b). Also note that I changed the second usage of
"activity" to "inactivity", which is what I think that
Stephen meant.

[Lyle McDon]

Robert Dorf wrote:
>
> On Wed, 14 Aug 2002 00:15:12 GMT, Lyle McDonald
> <lylemcd@onr.com> wrote:
>
> >Stephen Diamond wrote:
> >>
> >> In article <3D593651.B97D5460@onr.com>, Lyle McDonald
> >> <lylemcd@onr.com> wrote:
> >>
> >> > Stephen Diamond wrote:
> >> >
> >> > > However, the distinction can in principle be settled
> >> > > empirically, and in this instance, perhaps not _only_
> >> > > in principle. Do animals who hibernate for months on
> >> > > end lose cardiovascular conditioning?
> >> >
> >> > I have no idea, but they spare protein like crazy. They
> >> > actually lose zero LBM during hibernation. One of a few
> >> > animals that adapted to doing so (King Penguin is
> >> > another, and there's a third that I forget).
> >> >
> >> > > In _their_ case, it _would_ be maladaptive to lose
> >> > > conditioning because of inactivity.
> >> >
> >> > Why?
> >>
> >> If I am right that it was NOT maladaptive for human
> >> dependence on exercise to maintain fitness on account of
> >> the high activity level of our ancestors,
>
> >I can't work my way through this double negative and figure
> >out what you're saying.
>
> Mongo Translator say:
>
> "Me think that historically it not problem that human need
> exercise to not be so fat and flabby, because human
> ancestors always run and play. That why they stay fit and
> not be fat and flabby."
>
> >But see below, I've got an entirely different hypothesis.
> >
> >> then an animal which could ONLY maintain its fitness over
> >> time by naturally retaining it during long periods of
> >> activity would not show exercise dependence for fitness.
> >
> >Can't figure out what you're saying here either. Either
> >you're being obtuse or I'm just being dense today.
>
> Mongo Translator say:
>
> "If that am true, then maybe big animal that must spend long
> time without exercising (like sleepy bear in cave) would
> have to be able stay fit even if never exercise. Animal like
> that would never need exercise."

I miss John Carlo's clarity and erudition.

Lyle

[Stephen Di]

In article <9ncolus8omh7kdvnp1rtia2063rv13j1ok@4ax.com>,
Robert Dorf <robertdorf@japan.com> wrote:

> On Thu, 15 Aug 2002 19:23:51 GMT, Lyle McDonald
> <lylemcd@onr.com> wrote:
>
> >Stephen Diamond wrote:
> >>
> <snip>
> >> See Robert Dorf's translation.
> >
> >It still made zero sense to me.
> >
> <snip>
>
> I'll take one more (non-jokey and probably futile)
> shot at it.
>
> Stephen D Posted:
>
> >>> If I am right that it was NOT maladaptive for human
> >>> dependence on exercise to maintain fitness on account of
> >>> the high activity level our ancestors, then an animal
> >>> which could ONLY maintain its fitness over time by
> >>> naturally retaining it during long periods of activity
> >>> would not show exercise dependence for fitness.
>
> It looks like a faulty if / then statement to me. It might
> parse as; "If I'm right and human dependence on exercise for
> fitness was not a problem for our ancestors thanks to their
> high activity levels, then an animal which had to maintain
> its fitness despite long periods of inactivity would not
> need to exercise in order to remain fit."
>
> The statement remains incorrect, as (a) does not in fact
> necessitate
> (b). Also note that I changed the second usage of
> "activity" to "inactivity", which is what I think that
> Stephen meant.
>
>

In the summary above, some premises are only implied. Let me
put it more explicitly:

***If our ancesters did not evolve mechanisms to maintain
fitness through inactivity because of their inevitably high
activity level, then organisms that naturally go through long
periods of inactivity would probably have evolved such
mechanisms. ***

Stephen Diamond

[Lyle McDon]

Stephen Diamond wrote:
>
> In article <3D599E9D.A2F268AB@onr.com>, Lyle McDonald
> <lylemcd@onr.com> wrote:
>
> > I can't work my way through this double negative and
> > figure out what you're saying. But see below, I've got an
> > entirely different hypothesis.
>
> See Robert Dorf's translation.

It still made zero sense to me.

> > > then an animal which could ONLY maintain its fitness
> > > over time by naturally retaining it during long periods
> > > of activity would not show exercise dependence for
> > > fitness.
> >
> > Can't figure out what you're saying here either. Either
> > you're being obtuse or I'm just being dense today.
>
> Robert Dorf was kind enough to provide a translation.

it still made zero sense to me.

> > None of it may be particularly costly on the whole body
> > level, but on an individual cellular level (which is how
> > the cells are going to look at
> > it), it's all energy taht could be otherwise spent on
> > something else.
>
> The cell may be the basic physiological unit of analysis,
> but it isn't the right evolutionary unit. What the cells is
> selected for doing depends on the survival of the organism
> (or more exactly, of its genes).

True, but any individual cell (for the most part) is still
what's adapting/de-adapting. Yes, there are also whole-body
signals being sent (hormonally) but energy cost on a cellular
basis is still of great importance to whole organism survival.

> > But being able to do that requires a lot of flexibility
> > and a lot of adapatiblity. IMplicit in that, is the
> > ability to de-adapt as well. Why? Because if you adapt to
> > something and that change becomes permanent, you can't
> > very well adapt to a different stimuli. That is, say
> > you're in an environment which requires high levels of CV
> > fitness. Fine, you adapt over time. But now you get moved
> > into an environment that requires high strength fitness
> > for survival. If your muscles, heart, etc. are 'locked
> > into' cardiovascular adaptations, you wouldn't be able to
> > adapt. To survive in teh new environment requires not only
> > that you re-adapt to the new stimuli, but de-adapt to the
> > old one (esp. considering that the adapations are
> > essentially at opposite extremes in terms of energetics,
> > etc.).
>
> This may be true, but I don't think the evidence supports
> it. Someone more knowledgeable than I should comment, but as
> far as I know, CV fitness has no significant drawbacks.

You're missing the point I'm trying to make. And I never said
that maintaining CV fitness necessarily had drawbacks except
inasmuch as that it's energetically wasteful for the body to
maintain adaptations (energy costly adaptations as I listed)
that it has no need (need = being given regular stimuli) to
maintain. And you see those types of changes in most sytsems
of the body. Provide stimuli, the system adapts; take it away,
the system de-adapts. What the system is per se is wholly
irrelevant.

Take away a given nutrient (i.e. carbs) and the body stops
making as much carb digesting enzymes. There's simply no need
in the absence of a stimuli.

Take away bone loading and the body breaks down bone. Now,
there's no significant drawback to maintaining bone density
(same argument you're making for CV fitness) except that it
would make no sense for the body to maintain an energetically
costly system that it's not using.

Take away muscular loading (space flight being an extreme
example, or look at bed rest) and you get severe muscular
atrophy (and bone loss). Now that's obviously maladaptive
(well, when you return to a gravity well) because it
compromises function. But the body doesn't care, it's simply
adapting/deadapting to the presence/absence of a stimuli.

The body is an adaptable/plastic system. Implicit in the
ability to remain plastic is that it should adapt to stimuli
and de-adapt to a lack of same. Removing a CV stimuli means
de-adaptation, whether or not it would be a 'drawback' to
maintain it (and it would be a drawkback in that hte body is
using energy for something that it sees no 'need' for).

I think your mistake is still thinking in terms of the body
'thinking' "well, even though there's no stimuli, this is a
good adpatation to maintain, just in case" which isn't how it
works. It's simply adapating/deadapting to the various stimuli
being thrown at it.

>If it does, I think a lot of people would like to know what
>they are. The conventional wisdom is that it is an unalloyed
>blessing, beneficial even to performance in purely cerbral
>activities. If what you are saying were true, there would be
>athletic performances for which it would be _preferable_ NOT
>to have CV fitness

When you detrain an endurance athlete, his muscular strength
and power output go UP. So any strength activity requiring
maximal strength/power output can be hampered by adaptation to
CV training (note that most OL'ers do zero aerobic training
for that very reason).

Numerous studies show interference (meaning decreased total
adaptations) when you try to adapt to both maximal strength
and endurance at the same time. That is, adapting to either
pure strength or pure endurance tends to give you greater
adapations than trying to adapt to both (for the most part).

> Also, if loss of fitness in humans was part of a
> specifically human adaptational template, other mammals
> would NOT lose fitness with activity. The ones I have known
> do. But, I haven't known any bears.

You're still thinking far too specifically IMO. Forget
fitness, just think in terms of adaptations in general. Other
animals do adapt, within some range, but humans tend to have
the greatest adaptability overall (then again, other animals
can make up for a lack of adaptability in any given generation
with a shorter life span).

In any event, it's quite likely (as I think you originally
posited) that there is, of course, some minimal amount of
activity that is consistent with 'basic
adaptation'/fitness/whatever. Obviously if you put a rat in a
microgravity environment it will lose all kinds of fitness.
Put a man into space and you get the same thing.

There's a good bit of data showing that there is a fairly
mimimal threshold to get basic CV (or strength) conditioning.
Probably fairly consistent with what our 'average' activity
was in evolutionary terms. Obviously if you go to an extreme
below that (sit on ass all day), you're going to see
decrements.

AT the same time, beyond a certain high end, you get vastly
diminishing returns in terms of increases. So you're looking
at threshold events at the low end and asymptotes (or nearly
so) at the high ends. In some range, you maintain basic
functioning.

Then again, completely hibernating/inactive animals are the
exception to teh rule. Most animals don't go through that, so
even if there were data on bears, it would be an exception to
most critters (same as the protin sparing adaptations are an
exception, the only animals that spare 100% protein are the
few that hibernate, it was an adaptation that had to occur for
survival).

Anyhow, the ultimate point is that I think yo'ure still
ascribing far too much 'purpose' to the adaptations taht the
body undergoes, as if it was doing it with a specific outcome
in mind. I don't think that's how it works. The body adapts
to stimuli (i.e. regulare CV training which 'tells' it to
adapt) and de-adapts to the removal of that stimuli. Whether
or not *we* ascribe some benefit to that isn't the issue;
it's just how the body works, adapting and de-adapting in
response to stimuli.

Lyle

[Stephen Di]

In article
<stephend15-1A8791.15105915082002@news.mindspring.com>,
Stephen Diamond <stephend15@mindspring.com> wrote:

> In article <9ncolus8omh7kdvnp1rtia2063rv13j1ok@4ax.com>,
> Robert Dorf <robertdorf@japan.com> wrote:
>
> > On Thu, 15 Aug 2002 19:23:51 GMT, Lyle McDonald
> > <lylemcd@onr.com> wrote:
> >
> > >Stephen Diamond wrote:
> > >>
> > <snip>
> > >> See Robert Dorf's translation.
> > >
> > >It still made zero sense to me.
> > >
> > <snip>
> >
> > I'll take one more (non-jokey and probably futile) shot
> > at it.
> >
> > Stephen D Posted:
> >
> > >>> If I am right that it was NOT maladaptive for human
> > >>> dependence on exercise to maintain fitness on account
> > >>> of the high activity level our ancestors, then an
> > >>> animal which could ONLY maintain its fitness over time
> > >>> by naturally retaining it during long periods of
> > >>> activity would not show exercise dependence for
> > >>> fitness.
> >
> > It looks like a faulty if / then statement to me. It might
> > parse as; "If I'm right and human dependence on exercise
> > for fitness was not a problem for our ancestors thanks to
> > their high activity levels, then an animal which had to
> > maintain its fitness despite long periods of inactivity
> > would not need to exercise in order to remain fit."
> >
> > The statement remains incorrect, as (a) does not in fact
> > necessitate
> > (b). Also note that I changed the second usage of
> > "activity" to "inactivity", which is what I think
> > that Stephen meant.
> >
> >
>
> In the summary above, some premises are only implied. Let
> me put it more explicitly:
>
> ***If our ancesters did not evolve mechanisms to maintain
> fitness through inactivity because of their inevitably high
> activity level, then organisms that naturally go through
> long periods of inactivity would probably have evolved such
> mechanisms. ***
>

The only important difference between the earlier version,
which you correctly parsed, and the above is that probability
replaces necessity.

If you think it still doesn't follow, why not? What likely
scenario are you envisioning in which

1. Provided that humans needed to remain fit despite
inactivity, they _would_ have evolved mechanisms to
accomplish it. (The hypothesis under scrutiny) and

2. Other *mammals* (what I really should have written, instead
of "organisms") that would substantially benefit from
remaining fit despite inactivity FAIL to develop such
mechanisms.

I can think of scenarios (mostly having to do with path
dependence in evolution), but not probable scenarios.

Stephen Diamond

[Lee Kelly]

"Lyle McDonald" <lylemcd@onr.com> wrote in message
news:3D5BFD49.B5BEF625@onr.com...
> Stephen Diamond wrote:
> >
> > In article <3D599E9D.A2F268AB@onr.com>, Lyle McDonald
> > <lylemcd@onr.com> wrote:
> >
> > > I can't work my way through this double negative and
> > > figure out what you're saying. But see below, I've got
> > > an entirely different hypothesis.
> >
> > See Robert Dorf's translation.
>
> It still made zero sense to me.
>
> > > > then an animal which could ONLY maintain its fitness
> > > > over time by naturally retaining it during long
> > > > periods of activity would
not
> > > > show exercise dependence for fitness.
> > >
> > > Can't figure out what you're saying here either. Either
> > > you're being obtuse or I'm just being dense today.
> >
> > Robert Dorf was kind enough to provide a translation.
>
> it still made zero sense to me.
>
> > > None of it may be particularly costly on the whole body
> > > level, but on
an
> > > individual cellular level (which is how the cells are
> > > going to look at
> > > it), it's all energy taht could be otherwise spent on
> > > something else.
> >
> > The cell may be the basic physiological unit of analysis,
> > but it isn't the right evolutionary unit. What the cells
> > is selected for doing depends on the survival of the
> > organism (or more exactly, of its genes).
>
> True, but any individual cell (for the most part) is still
> what's adapting/de-adapting. Yes, there are also whole-body
> signals being sent (hormonally) but energy cost on a
> cellular basis is still of great importance to whole
> organism survival.
>
> > > But being able to do that requires a lot of flexibility
> > > and a lot of adapatiblity. IMplicit in that, is the
> > > ability to de-adapt as well. Why? Because if you adapt
> > > to something and that change becomes permanent, you
> > > can't very well adapt to a different stimuli. That is,
> > > say you're in an environment which requires high levels
> > > of CV fitness. Fine, you adapt over time. But now you
> > > get moved into an environment that requires high
> > > strength fitness for survival. If your muscles, heart,
> > > etc. are 'locked into' cardiovascular adaptations, you
> > > wouldn't be able to adapt. To survive in teh new
> > > environment requires not only that you re-adapt to the
> > > new stimuli, but de-adapt to the old one
(esp.
> > > considering that the adapations are essentially at
> > > opposite extremes
in
> > > terms of energetics, etc.).
> >
> > This may be true, but I don't think the evidence supports
> > it. Someone more knowledgeable than I should comment, but
> > as far as I know, CV fitness has no significant drawbacks.
>
> You're missing the point I'm trying to make. And I never
> said that maintaining CV fitness necessarily had drawbacks
> except inasmuch as that it's energetically wasteful for the
> body to maintain adaptations (energy costly adaptations as I
> listed) that it has no need (need = being given regular
> stimuli) to maintain. And you see those types of changes in
> most sytsems of the body. Provide stimuli, the system
> adapts; take it away, the system de-adapts. What the system
> is per se is wholly
irrelevant.
>
> Take away a given nutrient (i.e. carbs) and the body stops
> making as much carb digesting enzymes. There's simply no
> need in the absence of a stimuli.
>
> Take away bone loading and the body breaks down bone. Now,
> there's no significant drawback to maintaining bone density
> (same argument you're making for CV fitness) except that it
> would make no sense for the body to maintain an
> energetically costly system that it's not using.
>
> Take away muscular loading (space flight being an extreme
> example, or look at bed rest) and you get severe muscular
> atrophy (and bone loss). Now that's obviously maladaptive
> (well, when you return to a gravity well) because it
> compromises function. But the body doesn't care, it's simply
> adapting/deadapting to the presence/absence of a stimuli.
>
> The body is an adaptable/plastic system. Implicit in the
> ability to remain plastic is that it should adapt to stimuli
> and de-adapt to a lack of same. Removing a CV stimuli means
> de-adaptation, whether or not it would be a 'drawback' to
> maintain it (and it would be a drawkback in that hte body is
> using energy for something that it sees no 'need' for).
>
> I think your mistake is still thinking in terms of the body
> 'thinking' "well, even though there's no stimuli, this is a
> good adpatation to maintain, just in case" which isn't how
> it works. It's simply adapating/deadapting to the various
> stimuli being thrown at it.
>
> >If it does, I think a lot of people would like to know what
> >they are. The conventional wisdom is that it is an
> >unalloyed blessing, beneficial even to performance in
> >purely cerbral activities. If what you are saying were
> >true, there would be athletic performances for which it
> >would be _preferable_ NOT to have CV fitness
>
> When you detrain