Re: john disects your message!:mutations and reproduction

john queen (john.queen.ii@mail.utexas.edu)
Wed, 18 Jun 1997 17:06:28 -0500

At 02:07 PM 6/18/97 -0500, you wrote:
>John Queen writes:
>
>> I agree. Recombination of genetic traits at reproduction has been
>>the only usefull avenue. My son looks more handsome than I, but he doesn't
>>have a third arm or nostril or a third lung or anything new except for
>>traits that have been in my family and my wifes for years that have
>>nothing to do with mutations but everything to do with reproduction.
>> Is there an example of otherwise?
>> john w queen ii
>
>Yes there are examples of otherwise. Some of the most dramatic examples of
>how minor genetic changes can cause major phenotypic alterations are found
>in developmental biology labs. Minor genetic alterations have totally
>rearranged the organization of body plans and wing formation in insects.
>Eyes have grown inside a frog's mouth, other body parts have been placed in
>unusual locations. The relevance that all this has to evolution is to
>demonstrate that small genetic changes can result in major alterations.
>When this happens inside the lab, the unusual phenotypes are generally
>advantageous for the simple reason that the researcher selects the mutants
>and discards the less interesting variants or normal animals. This is an
>example of how mutation can affect a phenotypic change that provides the
>organism with a selective advantage (albeit the selection is "artificial").


>Now the question becomes, can similar processes result in selection of very
>distinct morphotypes under "natural" selection. Well, the answer is that it
>depends upon whether or not the mutation produces an adaptive phenotype.
>Population ecologists would argue that most species which exist at a given
>time, represent those best suited for the environmental niches that are
>available. It is further argued that when the environmental niches become
>drastically altered, then the selection pressure increases, and at that time
>one would find evidence for rapid speciation. Some say that the evidence
>from the fossil record supports this contention that tremendous speciation
>followed large environmental events.
>
>Under this explanation, in the absence of large changes in environmental
>niches, one would not expect to often find examples of evolutionary change.
>The fact that "naturally" ocurring mutations that we observe to result in
>significant changes in phenotype are usually deleterious, is also consistent
>with the notion that in a relatively constant environment, selection
>pressure is not sufficient to drive major morphological changes.
>
>It is important to keep in mind that this is a model that is supported by
>some data, but that also suffers from the absence of other supporting
>data--such as direct observation of evoloution of lungs in fish, for
>example. It is also important to keep in mind that the absence of such
>observational data is not inconsistent with the model, and to cite such
>holes in the record as convincing evidence against the model is not a very
>compelling argument.
>
>Cheers,
>
>Steve
>_________________________________________________________
>Steven S. Clark, Ph.D . Phone: 608/263-9137
>Associate Professor FAX: 608/263-4226
>Dept. of Human Oncology and Email: ssclark@facstaff.wisc.edu
>UW Comprehensive Cancer Center
>CSC K4-432
>600 Highland Ave.
>Madison, WI 53792
>
>"It is the glory of God to conceal a matter, but the glory of kings to
>search out a matter." Proverbs
>________________________________________________________
>
>

---Steve--

I dont see how directly manipulating or altering genetic material to
create animals that are severly handi-capped could support the notion that
random genetic mutations followed by any natural process could lead to
anything more usefull than what youve described.
I dont think that environmental pressures could ever influence the
propogation of mutations to favor a new envoronment. It's like saying a
insects mouth will evolve so it can eat on a flower.
I will leave my main point that has be ran over by everyone that has read
my comments (almost). Natural selection can only act on the expressed
parts of the genome. So how did anything of complexity evolve? Take the
human ear, how did it evolve? Somewhere along the line a functioning ear
had to appear at once from random mutations(without natural selection).
Unless somehow natural selection has a mind and knows that this mass(you
and I know it had to start further back than this) of tissue and nerves
will someday be of use to the body.
My main points are these: I dont think random mutations have not been
shown to do what evolution claims and that natural selection is not a
viable mechanism, it's reasonings have been distorted to fit the picture of
evolution.
I appreciate your comments and your input.

john w queen ii