Bert Massie writes:
>David
>This is speculation not explanation. Where is the evidence that at a
>time of severe stress for whatever the cause that a blind animal
>suddenly developes the ability to see by this mechanism? Certainly if
>you believe as I do that these rapid periods of invention occured you
>must postulate a means to make it happen. However, I still do not see
>a viable mechanism. If you believe in this above postulate, may I ecourage
>you to take some fruit flies (take a large population and the little
>animals breed rapidly) and get some experimental evidence for inventive
>genetics (sorry, bigger wings or different color will not do). I want to
>see some new body feature of import. This is not a hard experiment and
>the numbers of generations and population levels should be adequate.
Hmmm...
Well, there are cases such as the antifreeze proteins of some fish that
appeared
to have been co-opted from other metabolic processes. There are numerous
forms of lens crystallins (proteins which increase the refractive index
of animal lenses) which were definitely borrowed from other functions (and
which actually retain the original enzymatic activity). Flowers are
particularly
interesting: A few years ago there was a case found where a few changes in
flower development lead to speciation (Orchids are particularly interesting).
And speaking of fruit flies, try looking up a good, detailed book on
Drosophila species in Hawaii or cichlids in Lake Victoria (or cichlids
anywhere, for that manner) and see what morphological, habitat and
behavioral diversification (and innovation) can occur in a few million
years (or much less).
Actually, I've put bacteria through a few generations and come up with
irreducibly complex systems (Just about every microbiologist who has
worked with suppressor mutations has done so). The development of an IC
system also showed up in bacterial resistance to antibiotics where
secondary mutations were selected that enabled a streptomycin resistant
mutant to compete with the wild-type even in the absence of the antibiotic.
One last thing. Bert, when you discuss evolutionary mechanisms and
natural selection, do you considered the role of neutral variation
in non-direct routes to evolutionary adaptations?
Regards,
Tim Ikeda
tikeda@sprintmail.hormel.com (despam address before use)
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