Re: No environment is static, but the phenotypic embodiment of genotypic

On Apr 22, 6:37 pm, derdag <der...@xxxxxxxxxxxxxxxxxxxx> wrote:
On Apr 22, 9:20 pm, Boswell <j...@xxxxxxxxxxxx> wrote:



On 22 Apr 2007 17:00:34 -0700, derdag <der...@xxxxxxxxxxxxxxxxxxxx>
wrote:

On Apr 22, 7:30 pm, John Harshman <jharshman.diespam...@xxxxxxxxxxx>
wrote:
derdag wrote:
No selection of genetic change occurs until the change is expressed
phenotypically and also provides an advantage within that immediate
environment. As the environment continues to transform in terms of
competition and climate, the previous change 'which allowed fitness
for "that" transient new environment' seems to be retained. Let's
call this the derdagian paradox.

Sorry. You will have to explain more clearly just what this "paradox"
is, because so far I have no clue.

We'll either hash it out with random
incremental mutation, or we will find whole code sets which seem to be
placed into unrelated Kingdoms of the Tree of Life which could have
been placed "plausibly" as 'contingencies' for species designed to
adapt to a changing environment.

"Whole code sets"?

Do your homework, kids. I'm not going to sit here and let anyone put
words into my mouth and spam your trolls with beliefs and special
circumstance hypotheses. This is a scientific problem.

It may be, but it's impossible for me to tell until you explain more
clearly what the problem is.

[snip]

Hey, John~~

Yeah. Derdagian Paradox. Scientific problem. Nice ring to it.

We have evidence of snowball earth, warming and cooling periods, high
COO levels, reducing atmosphere, O2 increases, reptilian population,
mammalian emergence into the prominents in the context of fauna and
all types of variation "environmentally." Traits, which are
phenotypic expressions of genotypic change, are the only thing tested
by environments through the natural selection process. genotypic
change isn't necessessarily tested, because it may not be expressed
phenotypically. When a change works in the instant environment, it
produces progeny which may be fit to survive more aptly. Only those
can be passed on and through success, plus more random genetic change
and phenotypic expression, can be selected.

Show us some novel "random" "incremental" "selected" changes that
revert a species back into a configuration 'phenotypically' like a
previously expressed morphology which seemed fit for a previous cycle
through some kind of similar environment in the past where the
organism existed with past features, but different genetic code.

I don't know about John, but I have expended much energy bravely
hacking my way through your thicket of tangled verbiage. As near as I
can figure, you think evolutionary theory predicts that species will
revert back to some ancestral species if an environment is encountered
resembling the environment that the ancestral species inhabited. Is
that right? If so, could you provide an example of a species which you
think should be in process of reverting?

We do not see species lines disposing of 'once useful code' and
randomly developing novel answers for each time that the species finds
itself in an environment which is like one from millions of years
ago. Pretend that man is the only species which can travel great
distances, into hostile climates within one lifetime. Also, assume
that the climate of a particular place on the globe can experience
nearly instantaneous change in environment.- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

As stated, the ToE predicts that a species will adapt to an
environment through random, incremental change selected by natural
selection because of fitness to an environment that the individual
organism is residing within.

Close enough.

Because of this stated principle of the
ToE, and recognizing that the environment of (a particular geographic
area) has undergone change cycles, we should have seen fossil evidence
of an organism type which has also cycled in its morphological
characteristics by way of independent genetic variations that spelled
out similar physical characteristics.

First, the species has likely lost any remnants of the genes which
made it what it was before its present form. Why would you assume that
an improvement from its *current form would be any sort of
backtracking to its prior form? In any event, the specie could *not
"backtrack" if the proper mutations do not show up. Recent adaptations
may have given it new capabilities or new limitations. For any given
environment, we might see millions of multi-celled organisms that are
doing swell. For any given species B derived from species A (if you
can call an earlier form a different species), why would we assume
that "reversing direction in even the smallest degree would be
advantageous.

Let's look at an example. Mammals are derived from fish (over a long
process). A family of mammalian tetrapods (ateriodactyls) moved into
the ocean, and in time assumed a streamlined shape very similar to
some fish (like sharks).

But cetaceans are derived from tetrapods. Because of tetrapod
ambulation, the flukes of the cetaceans move up and down, while the
tails of fish move side to side. This is probably a neutral
difference, but one that is unavoidable given their evolutionary
history. The cetaceans are endothermic and very intelligent. Why
should they lose these very advantageous characteristics? They are
also limited in some ways by their breathing air. But if they
"learned" to breathe water again, IIUIC, they wouldn't be able to
maintain an endothermic metabolism.

Only *very simple (and therefore recent) changes can be, or are
expected to be, reversible. A famous example is the white/dark pepper
moth evolution 150 years ago.


But, the 'once useful code' is often retained and maintained.

No its not. Sometimes a gene is simply turned off, like thick fur in
humans or teeth in birds. But other changes and adaptations are going
on, and soon the old genes cannot be turned back on and still function
properly.

When humans are born with thick hair, they have problems like hair
blocking their ear canals and affecting their hearing, hair in their
eyes, nostrils covered and affecting their breathing, etc. And let's
not even talk about how well chickens accommodate teeth...

Perhaps
the 'now useful code' was retained and maintained, previously, not
novel random invention, presently.

Do you have any examples of this happening?

Kermit


.

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