Re: Biochemistry of Genetic Mechanisms

I will try to be more clear in communication. There are two processes
involved in evolution. The first process is environmental selection
(adverse environmental change) in a confined area; extinction is the
most common result. Sometimes, the environmental selection process
does not cause extinction; sometimes a second process involves a genome
response that results in an adaptation which allows survival in the
newly-created environment. I would envision the stem-loop action
previously discussed as the mechanism of adaptation. This adaptation
occurs as a biochemical process; however, selection (environmental and
natural) for survival is at the organism level. There must be enough
time to enable the genome response from stressful environmental
conditions (in a confined environment). This genotype response
requires genotype variation (that resulted from mutations) with the
potential to produce a surviving phenotype. The survivors have the
resultant genetic bias of natural selection (a change in gene
frequencies in a population, owing to fitness of phenotypes'
reproduction or survival among the variants).

This is a the view expressed in my book (copyright 2005); this is
something new and it is not a wordy rehash of the same ol' same ol....

RE: "I would put it like this. In order for NS to work, it is
essential for there to be variation in genotypes. Whether there is
variation (in time or space) in the environment is irrelevant. That is
the standard viewpoint on "microevolution" (the source of adaptation)
as I understand it. The standard viewpoint on "macroevolution"
(speciation and increased complexity over time) does see an essential
role for variation in the environment. But variation in genotypes
is also necessary for macroevolution to work under NS."

I agree that there must be genotype variation (from mutation); this
must enable a genome response from stressful encvironmental conditions
in a confined environment. I would envision the stem-loop action we
previously discussed as the mechanism of adaptation. I do not seperate
microevolution and macroevolution as you have. I would refer you to
Levinton's discussion of this. Michael Behe caused confusion by
separating micro and macro as he did, and to say that time and space
environmental influence is irrelevant is also similar to his claim.

Michael Behe, in Darwin's Black Box-The Biochemical Challenge to
Evolution, insists that natural selection cannot account for the
purposeful arrangement of parts that is seen at the molecular level.
Behe uses a "black box" as a whimsical term for a device that that
does something, but whose inner workings are mysterious - sometimes
because the workings can't be seen, and sometimes because they just
aren't comprehensible. He suggests that Darwin just didn't
understand what was in the black box of biochemistry, the intricate
workings of life itself. He maintains that the workings of life
essentially lie in the details of its complex molecular biochemical
machinery. He believes Darwinian evolution, chance variation resulting
in a competition advantage in the struggle for life, falls short in
applications to the fine details of biochemistry. He firmly believes
that the real work of life does not happen at the level of the whole
animal, and that "natural selection working on random variation"
breaks down at this most important molecular level. He further states
that at this most important molecular level, anatomy and the fossil
record are irrelevant. Still further black box analogy is made between
mutation and evolution, indicating a lack of evidence of interaction
between both.

Behe defines evolution "in the sense Darwin gave the word. (It)
means the process whereby life arose from nonliving matter and
subsequently developed entirely by natural means." Is this correct?
It is helpful to return to the original work to understand what Darwin
really said. Recall Darwin suggested that then present-day species
(different types of life) resulted from a common ancestor and changes
(anatomical adaptations via natural selection) occurring in each
isolated population. This theory of natural selection (the
preservation of favorable variations & the rejection of injurious
variations), as the explanation for the origin of species (different
types of life), seems to be less focused on the origin of life than on
the evolution of changes from that time on. It would seem to me that
anatomical changes and the fossil record would be essential to a
comprehensive understanding of evolution; this comprehensive
understanding should also include the biochemistry of anatomical
structure and function. Recall that variation is packaged as
combinations of traits within one individual organism. Expanding one
trait may then be at the expense of other traits. To be beneficial,
this new combination must enhance the overall survival chances of the
individual and/or offspring. The most effective combination for the
genetic variance of natural selection then becomes the most optimum
balance of all traits. This places the selective process for complex
life at a higher level than molecular chemistry, even though the whole
is made from the sum of the parts.

Behe could maintain that the origin of life and some simple forms of
life, for a period of around four billion years, function primarily at
the molecular level. The origin of life is still unknown; the
biochemical argument is inconclusive here. Simple forms of life, like
a virus or bacteria do mutate at the molecular level, do evolve, and do
seem to follow a pattern of natural selection (survival of the
fittest). A virus undergoes mutation (genetic change), which enables
it to invade new environments. Nevertheless, the selection process is
still at the level of organism survival, not at the level of a chemical
reaction. Bacteria develop biochemical-generated structural resistance
to (an environment of) antibiotics, and pass this survival advantage on
to their offspring. Again, selection is at the organism level, not at
the level of the biochemical reaction itself. Isn't there molecular
evolution involved in the biochemistry of the mutation allowing plants
to develop resistance to an environment of herbicides, and pass this
survival advantage on to their offspring? It is not the chemical
reaction alone that survives; it only survives due to environmental
selection at the level of the organism possessing the natural selection
mutation advantage. Similar molecular processes occur when insects
develop resistance to an environment of insecticides, and pass this
survival advantage on to their offspring. Molecular-level change in
the biochemistry of genetic mutation clearly produces natural selection
advantage in organism-level survival. Aren't these clear
interactions where random genetic variation is environmentally-selected
for a natural-selection genetic bias? Hasn't this molecular process
enhanced evolutionary survival value in a newly-created environment
(that is unfriendly to existing life forms)? Nevertheless, Behe
maintains that life is not accountable to natural selection at the pure
molecular level. What of natural selection accountability at even more
detailed, but even less appropriate, atomic or sub-atomic levels?
Behe, like Aristotle, considered natural selection as a cause for the
creation of different types of life and evolution; but, like Aristotle,
dismissed it in favor of teleology. Behe believes that: "All of
these things were designed because of the ordering of independent
components to achieve some end." Teleology, a black box itself, is
still alive and well.

Re: "My 'geo-Darwinism' can be described as a cause of extinction. But
geo-Darwinism without the neo-Darwinistic change in the gene
frequencies of populations is a fairly impotent force for change. So I
have to ask: what does your "environmental selection" do that my
"geo-Darwinism" doesn't do?"

Your "geo-Darwinianism" is involved as part of the selection process,
but in my story, heredity (natural selection) and environment
(environmental selection) get married and end up with the same last
name.


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Relevant Pages

  • Re: Insights Ive gained from my Bio class so far
    ... about problems with evolution, the examples they give of problem organisms ... percentage of the life on earth. ... the selection processes that caused their evolution in the first place. ...
    (talk.origins)
  • Re: Insights Ive gained from my Bio class so far
    ... about problems with evolution, the examples they give of problem organisms ... percentage of the life on earth. ... the selection processes that caused their evolution in the first place. ...
    (talk.origins)
  • Re: Species diversity through time
    ... that life is not some grand progression toward some predetermined goal. ... evolution in a more modern way. ... Large brains with thinking minds are attractors. ... he doesn't think much of selection. ...
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  • Darwinian Mechanism of Mutation and Natural Selection Found Lacking
    ... The conclusions are that life could ... darwinian mechanism of mutation and natural selection. ... The evidence for evolution is broken down into three broad ... Doesn't the fossil record show that organisms have evolved from simple ...
    (talk.origins)
  • Re: "Random evolution"
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    (talk.origins)