>I
>> believe there are some ideas on the evolutionary precursors of
>> photosensitive pigments, but do not remember any detail.
>************
>You do not remember any details because you were never given any.
Usually my memory is better than that. I could give you lots of details
about molecular evolution of the 18S gene in bivalves, as that is what I
actually study. Evolution of vision pigments is rather tangential. I'll
see what I can find as I have time, though.
>And I would like to see some evidence to support it.
There was an article a few years ago, I believe in American Scientist but
possibly Scientific American. New World monkeys normally have only one of
the red/green color pigments. A simple mutation will change from one to
the other. If an individual receives one version of the gene from one
parent and the other from the other, he will have full color visual
abilities.
>> >From a morphological point of view, any sort of eye from a single
>> photosensitive cell on up is useful.
>**************
>Morphology involves making pencil drawings which ignore the real details.
However, it is the information we have to go on at present. Also, the
genes have to express themselves in morphology.
>********************
>How about being accurate.
>
>"Complex eyes appear in the follil record at several different times.
>Those who prefer to see evolution as the mechanism believe that this was
>due to evolution and those who see a designer prefer to see his action
>in this."
>******************
The danger of pronouns! I see a Designer and prefer to see His action in
this mechanism of evolution as well as the rest of His creation.
>I did not speak of timing as to when. I spoke to the rate of
>development giving the amount of time available. I am looking for a
>solid rate of development times time equals organ type arguement.
For a certain amount of time to equal a certain level of development would
require evolution to always go the same way. This would also require some
quantified measure of organ development to really speak of a rate. I can
tell that some eyes are more complex than others, but I am not sure how one
could calculate what you request.
>Assuming I accept this at face value, now do a calculation with mutation
>rate, subtract the bad mutations, and give us a number for the potential
>additional information rate per year.
Mutation rate is not constant, nor is volume of biological information
well-defined. In a productive year, the amount of information could
double, but volume of information is not too meaningful. Useful new
information tends to be kept and bad mutations tend to be lost, so that
there is an accumulation and not just steady change. All this means that
the calculation of a precise rate requires more information that is
available, if not than can be available.
David C.
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