Back to square one

On Tue, 25 May 2004 23:48:26 +0000 (UTC), [email hidden] (Vivek)

Quoted message said:

I have heard that the Earth will reverse poles in a few
thousand years and that landmasses are slowly coming
together. Is this true for evolution too? I mean, is
the present scenario headed back to such a case where
humans will evolve back to their ancestors, or is it
going forward?

The earth's magnetic poles have reversed some 300 times,
now. The average interval between reversals is 700,000 years
but it varies from 100,000 to tens of millions. The last one
was 780,000 years but no one knows when it will happen
again. Probably no big deal. Certainly nothing unusual.

The continental plates are in constant motion. Some are
spreading apart, others are crashing into each other.
This has been going on for billions of years. Again,
nothing unusual.

None of these phenomena represent things "going backwards".
It is just "change, as usual".

[email hidden] (Vivek) on 25 May 2004 posted

Quoted message said:

I have heard that the Earth will reverse poles in a few
thousand years

the poles tend to reverse. Sometimes whats at the south pole
of the planet is an actual magnetic south pole, other times
its a magenetic north pole, like now.

(the north needle is repelled by it, see)

Quoted message said:

and that landmasses are slowly coming together.

Plate tectonics. Since the plates are on a globe, I suppose
any motion could be viewed as ultimately leading to the
plates being brought back together. But right not, the
atlantic ocean is growing, so take that as a frame of
reference.

Quoted message said:

Is this true for evolution too? I mean, is the present
scenario headed back to such a case where humans will
evolve back to their ancestors, or is it going forward?

No its not true of evolution. Species don't reverse their
'evolution' and become their ancestors. Sometimes ancestral
-like- characters are formed. And people like to say that
parasites have 'degenerated', but evolution, having no
direction, certainly couldn't 'reverse' direction.

R.Schenck <[email hidden]> wrote or quoted:

Quoted message said:

And people like to say that parasites have 'degenerated',
but evolution, having no direction, certainly couldn't
'reverse' direction.

Since when has evolution had no direction?

Evolution has several powerful directional components.

For instance it is getting increasingly effective at
capturing energy from the sun, degrading it and re-
raditating it as heat.
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Tim Tyler <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

R.Schenck <[email hidden]> wrote or quoted:

Quoted message said:

And people like to say that parasites have
'degenerated', but evolution, having no direction,
certainly couldn't 'reverse' direction.

Since when has evolution had no direction?

Evolution has several powerful directional components.

For instance it is getting increasingly effective at
capturing energy from the sun, degrading it and re-
raditating it as heat.

So is a parasite devolved or evolved? Has a more well
adapted species of cestode that pushes its competitor
species into extinction evolved in the forward direction or
the reverse direction?

I don't know about the energy from the sun bit, but its not
like animals evolve up a scale to 'higher and higher
levels'. I'll agree that an evolutionary trend at any given
moment could be said to have some sort of relative
direction, but all of evolution doesn't seem to be moving in
one direction.

R.Schenck <[email hidden]> wrote or quoted:

Quoted message said:

Tim Tyler <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

R.Schenck <[email hidden]> wrote or
quoted:

Quoted message said:

Quoted message said:

Quoted message said:

And people like to say that parasites have
'degenerated', but evolution, having no direction,
certainly couldn't 'reverse' direction.

Since when has evolution had no direction?

Evolution has several powerful directional components.

For instance it is getting increasingly effective at
capturing energy from the sun, degrading it and re-
raditating it as heat.

So is a parasite devolved or evolved?

I generally favour using the term "devolution" to refer to
compromise (and reduced fitenss). This often happens due to
mutational load.

Loss of components could perhaps /sometimes/ be described as
devolution - depending on the context.

Quoted message said:

Has a more well adapted species of cestode that pushes its
competitor species into extinction evolved in the forward
direction or the reverse direction?

That question is too vague to answer - and I should point
out that I never suggested that there were only two possible
directions.

Quoted message said:

I don't know about the energy from the sun bit, but its
not like animals evolve up a scale to 'higher and higher
levels'.

It is sometimes legitimate to say some lineages are evolving
in particular directions - but that depends on the lineage
in question and its environment. Arms races are one of the
most common example of directional elements in the evolution
of particular lineages.

Quoted message said:

I'll agree that an evolutionary trend at any given moment
could be said to have some sort of relative direction, but
all of evolution doesn't seem to be moving in one
direction.

It does to me. The bioshere is accumulating technology that
helps it more rapidly identify sources of potential energy -
and degrade them in the process of constructing offspring.

The accumulation is progressive, cumulative - and pretty
inexorable. Setbacks are possible in principle. However my
general perception is that meteorite strikes (and the like)
are not sufficiently common to cause major setbacks.

So: life does look a *lot* like a explosive process - where
we are witnessing the process shortly after ignition.

As with most explosions, there's a clear direction.

Our descendants will even be able to look back and see an
identifiable epicenter - with chaos and destruction
spreading radially outwards.
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Tim Tyler <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

R.Schenck <[email hidden]> wrote or quoted:

snip

Quoted message said:

It is sometimes legitimate to say some lineages are
evolving in particular directions - but that depends on
the lineage in question and its environment. Arms races
are one of the most common example of directional elements
in the evolution of particular lineages.

Ah ok, then we are more or less saying the same thing.

Quoted message said:

Quoted message said:

I'll agree that an evolutionary trend at any given
moment could be said to have some sort of relative
direction, but all of evolution doesn't seem to be
moving in one direction.

It does to me. The bioshere is accumulating technology
that helps it more rapidly identify sources of potential
energy - and degrade them in the process of constructing
offspring.

What do you mean by technology? The Commyn usage or
something more general/universal?

Quoted message said:

The accumulation is progressive, cumulative - and pretty
inexorable. Setbacks are possible in principle. However my
general perception is that meteorite strikes (and the
like) are not sufficiently common to cause major setbacks.

Why would meteor impacts cause a setback anyway? How would
it interupt the process of becomming more efficient at
energy abstraction?

Quoted message said:

So: life does look a *lot* like a explosive process -
where we are witnessing the process shortly after
ignition.

Hows that?

Quoted message said:

As with most explosions, there's a clear direction.

Torwards what, overall efficiency? Of what? The biosphere
as a whole?

Quoted message said:

Our descendants will even be able to look back and see an
identifiable epicenter - with chaos and destruction
spreading radially outwards.

Assuming one compact abiogenetic event.

R.Schenck <[email hidden]> wrote or quoted:

Quoted message said:

Tim Tyler <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

R.Schenck <[email hidden]> wrote or
quoted:

Quoted message said:

Quoted message said:

Quoted message said:

I'll agree that an evolutionary trend at any given
moment could be said to have some sort of relative
direction, but all of evolution doesn't seem to be
moving in one direction.

It does to me. The bioshere is accumulating technology
that helps it more rapidly identify sources of potential
energy - and degrade them in the process of constructing
offspring.

What do you mean by technology? The Commyn usage or
something more general/universal?

I'm counting things such as chloryphyll and haemoglobin as
"techology".

I.e. it's appilied scientific knowledge, knowledge
about tools.

Quoted message said:

Quoted message said:

The accumulation is progressive, cumulative - and pretty
inexorable. Setbacks are possible in principle. However
my general perception is that meteorite strikes (and the
like) are not sufficiently common to cause major
setbacks.

Why would meteor impacts cause a setback anyway? [...]

By destroying the knowledge the evolutionary process
accumulated.

Quoted message said:

How would it interupt the process of becomming more
efficient at energy abstraction?

If they succeed in destroying the relevant information,
repeated large impacts could cause significant setbacks -
and indeed could slow or even reverse progress.

Quoted message said:

Quoted message said:

So: life does look a *lot* like a explosive process -
where we are witnessing the process shortly after
ignition.

Hows that?

We're still near the start of the process.

Quoted message said:

Quoted message said:

As with most explosions, there's a clear direction.

Torwards what, overall efficiency?

Directions don't have to be towards some particular
landmark.

However in this case, "rapid burn rate", seems to be the
most evident object on the horizon. Increased rate of
increase of entropy.

"Efficiency" seems to be a bit of a secondary concern.

Quoted message said:

Of what? The biosphere as a whole?

Life. Living systems.

Quoted message said:

Quoted message said:

Our descendants will even be able to look back and see
an identifiable epicenter - with chaos and destruction
spreading radially outwards.

Assuming one compact abiogenetic event.

Yes - as apparently observed. In the case where there are
multiple sources of life in the universe, there will be
multiple epicenters - and the long term effect will be a
universe that fills up with living systems - rather than
living systems that spread radially outwards.
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