| MadSci Network: Genetics |
Dear Peter Kot:
I believe that current evolutionary/genetic thought understands this
so-called 'junk DNA' (which may account for some 80% of our DNA sequences)
as possibly being pertinent to the chances of survival versus demise of
particular species in the face of environmental changes. In other words,
the more junk DNA lying around the better the chance that under new
environmental stressors that a beneficial mutation(s) will be expressed and
allow for the adaptation of the species to the new environment. However,
unlike the very documentable and fact-ridden basis for evolutionary science
as a whole, these ideas on the role of 'junk DNA' are very theoretical. As
to whether there was an increase or a decrease in the percentage of junk
DNA sequences between ancient humans and modern humans: 1) I don't believe
that we really know this percentage for early humans, and 2) until the
Human Genome Project is completed in possibly 2002 we won't have a
chance to know this for modern humans. Furthermore, it should be noted
that it is very difficult to have much certainty as to whether 'junk DNA'
is really that or has functions that we just don't understand yet.
Dr. Smerken
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