You are incorrect though. Without natural selection and random mutations
the theory of evolution is a sinking ship.
JQ: Natural selection is a theory or idea that will only 'float' if the
ideas
and theories of random mutaions are feasible. The evidence for natural
selection is the fossil record which is not really evidence for the
mechanistic aspects of natural selection.
I think you are incorrect to claim that the fossil record is evidence of
natural selection. It is more evidence of evolution.
JQ: In addition, the fossil record reveals patterns that natural
selection has a hard time explaining.
Examples ? Perhaps the problems to explain are not natural selection but
ours ?
JQ: So the only real evidence for natural selection is that random
mutations can contribute to the complexity of a genome thus enabling a
selection. This in itsself has only be theorized. The evidence for these
types of mutations is once again the fossil record and the explanation
that natural selection would pick out the most suited genomes.
Natural selection is not only hypothesized but observed John.
JQ: I think that much more attention needs to be placed on these two
concepts.
Often textbooks point to the fossils and the pictures without discussing
the concepts in a manner that is acceptable. Similarities in structures is
not enough evidence(for me) to except the thought that the two structures
came from one another over millions of years.
Perhaps not enough evidence for you but it shows that over time we observe
creatures who become more complex, we observe transitionals etc.
JQ: I appreciate Steves comments because I think he sees where I am coming
from despite my inability to put into concepts into words. I think that
evolution relies on these two concepts and that neither are very clear or
feasible. Thanks for your comments Jim.
Mutations are observed to take place. We also have seen natural selection
in action. It's not that hard to combine the two and realize that this is
a very viable mechanism for evolution.
At 12:27 PM 6/19/97 EDT, you wrote:
>Steve Clark writes:
>
><< It seems to me that there is evidence
>consistent with evolution, yet there are troubling holes in the data that
>one would like to see filled. It remains very possible that these holes
>will not be filled to the satisfaction of the model--but this remains to
be
>shown.>>
>
>Wow, I agree with this wholeheartedly!
>
>How can this be?
>
>I think because I now understand your distinction. You say:
>
><<Note that up to this point, I have only been speaking on a theoretical
>level.>>
>
>And I tend to agree with you on this, too. In the realm of pure theory,
one
>might make a case for natural selection. But I always jump immediately
back to
>the hard world of data AND common understanding. Thus, you write:
>
><< Essentially, the model says that a
>primordial ear would arise from random mutations, as you have claimed.
This
>initial mutation and expression of the phenotype occurs in the absence of
>any selective pressure. Then, if this phenotype allows the organism that
>has it to reproduce more effectively than an organism without the
primordial
>ear--this is when selection acts to fix the gene in the population.>>
>
>This is where I have always protested that the theory holds to a hopeful
>"reproduce more effectively" gap filler, even though we have nothing to
>support that. I also stated this, I'm sure you'll recall, as the
"imagined
>selective advantage" riff. In THEORY, one can say this always leads
natural
>selection to do its magic. But in FACT, it is difficult if not impossible
to
>believe, for me at least, that such mutations as a primordial ear or leg
or
>lung would ever have the lasting effect on population that is necessary
for
>the theory to meet the reality.
>
>Perhaps past differences can be traced to my failure to make the
distinction
>you made in your post.
>
>Jim
>