DNA Etc.

James Frelichowski thisisnotgonnawork@yahoo.com
Wed, 12 Jan 2005 17:55:03 PST
DNA markers are a beast of their own also.  We need to ascribe them to genes and genetic changes that lead to speciation.  The effects of selection and the environment on plant development are another twist to the story so differences in physical aspects of the plant are still invaluable to the study of plants.  Sometimes the polymorphism based on molecular markers can mutant in either direction and lead to convergent similarities among different genotypes or random difference in genotypes that should be similar by descent.  Speciation is caused by so many factors that there is no time here to list them all.  Studying the DNA is a small part of the whole as many samples are needed to see the frequency differences in populations.  We should target DNA markers to document the leaps and bounds that lead to speciation or irreversible (or slowly reversible) fingerprints left in the genome that gets passed on to the lineage.  Another reason to keep the classification based on morphological
 markers, DNA marker technology is expensive to start up, but I am the beneficiary of it, so let us have our cake and eat it too and use both approaches!
James Frelichowski

John Bryan <johnbryan@worldnet.att.net> wrote:

Dear Lee Poulsen:

I agree 100% with you. No one can deny the valuable contributions the
study of DNA can make. But that such upsets the composition of genera,
as we know them, and have known them for years, is, in my opinion, a
step in the wrong direction.

If differences are not visible with a 10 x hand held lens, then I
question the usefulness of the studies. Surely the objective is, and
should be, the identification of a plant.

Technology marches on, I am sure there will come a day when DNA samples
are found not to be the end of advancements in our knowledge of plants.

The nomenclature that has, and still does serve us well, should be,
again in my opinion, preserved. In my opinion, the new classification of
genera and species, should form a basis of a new and separate
classification, it should be recognized and be available to those who
would profit from such knowledge, such as breeders of the various

Is it not time, as progress is made, but before we destroy the
nomenclature that has served us so well, to consider another record of
such determinations, separate but hand in hand with that existing. Such
being available to those who can take advantage of recent
determinations, but not to the point of reclassification, and the
casting aside of tried and true divisions, based on DNA. I often wonder
just how many DNA samples are taken to assure conclusions reached are
indeed correct. Are, as an example, studies made of the DNA of the same
species from different geographic locations? Do clones of a species

Thank you for your comments, I agree with you. Cheers, John E. Bryan
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