Does Natural Selection have the causal power to direct a random source of change towards a fitness peak?

[NOTE: This is reposted from a current post in the thread started by
"backspace."]



On Sat, 04 Aug 2007 08:27:39 -0000, "Steven J."
<steven_j@xxxxxxxxxxxxx> wrote:

On Aug 4, 2:49 am, backspace <sawireless2...@xxxxxxxxx> wrote:
What is the difference between random and non-random Natural Selection?

Your question has no ... what was your term? Pragmatics?

It seems perfectly reasonable to ask about the random and non random
aspects of Natural Selection. And with respect to what aspects is
Natural Selection "random" or "non random." Atheists portray Natural
Selection in anthropomorphic and teleological terms, offer simplistic
examples, ignore significant environmental variables and the random
events that occur. For example, the fastest gazelle can still trip
and break its leg and be caught by its predator lion.


"Random," as used by evolutionists, means, "random with respect to the
needs of the organism."

Nucleotide point mutations are random variables in the sense that they
occur with a fixed frequency and according to a know probability
distribution. As such these mutations are random with respect to
EVERY attribute of the individual not just the single attribute of
NEED. The proposition "random with respect to the needs of the
individual" was offered by Darwin specifically to restrict
consideration of genuinely non random and teleological possibilitiies.


When it is said that mutations are random,
what that means is that, e.g. a fox born into a cold, snowy
environment is no more or less likely to have mutations for stocky
build, short ears, thick fur, or light fur, than a fox born into a
temperate forest environment or one born into a desert environment.

But whether a particular mutation spreads through a population is not
random with respect to the needs of the organism; a fox with a
mutation for thick fur is more likely to survive and leave many
offspring if it lives in the Arctic than if it lives in a Mexican
desert, whereas the reverse is true for a fox with a mutation for a
long-limbed, slender build. "Random natural selection" seems, at
first and, for that matter, at second glance like a contradiction in
terms.

Natural Selection can explain the change in frequency of EXISTING
characteristics within a population (as with the changing frequency of
finch beak sizes and industrial moth coloring) within limits defined
by the existing genome of the population through differential
reproduction and survival. How Natural Selection guided some
purported series of random mutations to achieve these novel
populations in the first place is never explained.

This also applies to examples of anti-bacterial resistance. Resistence
is developed as the result of a loss of sensitivity to the
anti-bacterial agent. That is, something was broken and usually this
"breaking" causes other problems for the organism making it less fit
outside the catastrophic enviroment. When the anti-bacterial
environment disappears the resistent mutatant variation almost
disappear. These are not examples of the Natural Selection adding
coherence, and progressive develpment to the otherwise random source
of change. And coherence and progressive development are what is
required to explain non random emergence and develpment to some novel
biological feature.

Finally Steven J ignores a host of problems associated with spreading
a large series of putative point mutations throughout the population
not the least of which is Haldane's Dilemma.


Now, one can speak meaningfully of non-random mutation:

Steven J can't do anthing such thing. At least not from his
misleading example.


natural
selection would have an easier time of it if, e.g. having some poison
in the environment made mutations for resistance to that poison more
common than they would be in an equally stressful environment that did
not contain that poison.

This assumes that there is suffient time given the mutation rate and
the reproductive rate to produce the number of changes to resist some
poison environment.

Behe's latest book using the malarial parasite's resistance to
malarial treatments (two mutations occurred together) illustrates
these problems and he concludes that the edge beyond which
neoDarwinism lacks the resources to tread is there---just beyond two
mutations. Behe shows that in its arms race with its human opponent
the malarial parasite has not been able to overcome human sickle cell
and beta thalasemia resistance to their attacks which would require
many more than two mutations to overcome even given its tremendous
reproductive rate and numbers.

Behe also reports that after a particular malarial treatment is
discontinued in an area (due to anti-biotic resistance) that the
malarial parasite population reverts back to the "normal" strain.
Again while this is evidence of natural selection in action it is not
a demonstration of the coherence and progressivity necessary to
explain the emergence and deveopment of novel structures, systems and
organisms.


By the same token, natrural selection would
work less well if a mutation that was useful in hot environments were
more likely to show up in cold environments, and vice-versa.

A mutation may not simply be an improvement with respect to one
environmental factor. There may be an offseting difficulty with
respect to other environmental conditions. Next Natural Selection may
"choose" a point mutation in the next generation which blocks or
negates the positive addition in the first. There is no evidence that
Natural Selection----that is, differential survival conjoined to
differential reproduction----can coherently and progressively lead to
novel complex structures, structures, systems and organisms.

All of the putative examples of Natural Selection in action, like
anti-bacterial resistance, involve at most two relevant mutations and
even these lead nowhere.


At third glance, perhaps some sense can be made of your question,
though. Natural selection, as scientists understand it, works to
adapt organisms to their present, particular environment. Natural
selection can't favor a trait that makes it harder to find food, or
avoid becoming food, or find a mate, here and now, even if, a few
centuries down the road, your descendants living in a different
environment would find that trait useful.

First, Steven J treats "Natural Selection" as if it were some
teleological agent which "works" on behalf of all organisms towards
some distant fitness "peak." It is nothing like this. It is little
more than a label which captures the effects of "differential
survival" conjoined to "differential reproduction." Steven J offers
an over simplified explanation which fails to take into account the
fact that stochastic events in any local environment often have a
significant effect on survival and reproductive success.


Natural selection
(differential reproductive success of variant offspring) could
therefore be said to be "random" with respect to any particular long-
term destination (e.g. at the start of the Triassic, natural selection
on basal archosaurs was not aiming at birds, and in a different
Triassic traits different traits, perhaps incompatible with evolution
into birds, would have survived) one might imagine for a population.

Natural Selection yields adaptation to changing local environments and
then only with respect to the expression of EXISTING characteristics
not future ones. As Steven J reports these changes are effectively
random with respect to any putative progressive change. S. J. Gould
doubted that a case could be made for natural selection having any
bias for leading to progressive complexity; he rather saw the
opposite.

How this leads to the conclusion that Natural Selection is non random
with respect to the emergence of novelty is beyond me and would seem
to argue against the neoDarwinian mechanism having the sufficient
causal power to explain biological diversity.



Natural selection *now* isn't, e.g. favoring traits in racoons on the
grounds that, fifty million years from now, those traits will be
useful when their descendants evolve abstract intelligence and
language.

If "natural selection" were less of a metaphor -- if it really
involved some "thing" that actually examined and selected -- this
might not be so. One might conceive of a neo-Lamarckian sort of
selection that always kept in mind where a lineage was supposed to be
heading over the long term. But currently, no mechanism is known or
even imagined that could accomplish this.

But there is an alternative---intelligent design. ID has the causal
power to explain the origin of complex structures, systems and
organisms. Darwin dismissed design by using an argument from
imperfection. Gould used the same argument to dismiss design when
discussing the Panda's thumb. Both were theological arguments not
scientific ones. Behe's and Dembski's argument trump Darwin and Gould
by using accepted to science to introduce ID.

Behe's ID argument is grounded in real world biology and in what is
biologically reasonable as opposed to atheist theoretical
possibilities and if-so stories. Dembski's ID argument is well
grounded in the accepted sciences of Information Theory and
Probability Theory. So far the atheist world has been impotent
against Irreducible Complexity and no one has shown any fatal flaws in
Dembski's theory.

Behe's current argument concerning the limits of the neoDarwinian
mechanism is even more devasting than IC

Regards,
T Pagano




-- Steven J.


.

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