Ask A Scientist General Science Archive

name        Adelheid
status       student
grade        9-12
location     N/A

Question -   Does mutation of the genes cause deformity and
degeneration all the time? Unlike what we are taught to believe in the
case of Evolution?
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While it is true that the majority of mutations will often cause a protein
to work less well, or not at all, occasionally a mutation can produce a
protein that works better, faster, or in a completely novel way. This second
type of mutation plays a key role in evolution. Mutations are very much a
part of the evolutionary process!

Paul Mahoney, PhD
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The vast majority of mutations produce proteins that are not functional in
relation to the protein that it replaces.  This often results in a critical
failure to the individual.  However, occasionally, the mutation produces a
protein that is functionally superior or benetifical to the organism, and
this could mean a ground work to better survival or even a different
individual or species.  If you have studied hox genes or homobox
relationships, this explains a great deal on how a mutation may effect a
large change.

Sexual reproduction and mutations are fundamental to evolutionary change.
No two individuals are alike.  (Even identical twins are only alike by
genetics, but often differ.)  This is true of all organisms and helps
explains why new species can evolve.

Steve Sample
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 If you were taught that mutation always causes deformity and degeneration
all of the time, then you weren't taught the whole story.  Mutation is just
a change in the genetic code.  The word generally has a bad connotation, but
mutation can give an organism an advantage depending on the environment.  A
perfect example is the protein receptor, known as CCR5, that allows the HIV
virus to attach to T cells.  Some people have a mutated receptor which means
that their receptors are non-functional.  Thus, the HIV virus, even though
it is in the body and these people will have a positive blood test for HIV,
can't gain entry into the cells and therefore these people will not get
AIDS.  I'd call that a positive mutation in an environment where AIDS is
rampant.  By the way, some scientists have speculated that this is the same
receptor that the bubonic plague used to attack cells, and that people who
survived the bubonic plague passed this mutation down to their offspring.
Some people who have been shown to have the mutated CCR5 receptor can trace
their ancestry back to Europe in areas where bubonic plague struck.  PBS has
a series called "Secrets of the Dead" and one of the episodes was called
"The Secret of the Black Death".

vanhoeck
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Very good question. Yes, most often mutations cause deformity because the
body needs a certain amount of information in order to work properly. Too
little or too much information can cause horrible problems. However, some
mutations might cause some problems while enhancing other abilities. For
instance, people with autism might not be able to do normal daily tasks like
drive a car or even cook a meal, but remember everything that is said and
done down to the date and time for their entire lives. We are still in the
process of understanding why some mutations actually increase abilities yet
take others away.

Grace Fields
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