Re: Teaching science/Christianity to middle schoolers

As already pointed out, most mutations are neutral, not
harmful (though before the availability of extensive DNA
sequencing due to major technological innovations
beginning in the late 70's, harmful ones were by far the
easiest to detect). Whether a mutation is beneficial or
harmful depends entirely on the environment. Thus, the
attempt by some antievolutionists to dismiss some
observed beneficial mutations because they may be
detrimental in other situations is not valid. The phrase
"survival of the fittest" may contribute to misunderstanding
here; actually all of the fit enough survive, with "enough"
varying extensively, depending on the environment.

Even with a specific defined goal, most mutations, if not
neutral, have relatively small effects. The chance of a
significantly beneficial or harmful mutation depends rather
strongly on how close your starting point is to your goal.
E.g., when trying to make a normal human being, starting
from normal human DNA, a major mutation is likely to be
detrimental. When trying to make a totally novel function,
starting from an existing gene, big mutations have a decent
chance of being an improvement.

This also raises the problem of "goals" in evolution. One of
God's goals seems to be to produce a lot of diversity, but
evolution itself has no goals of its own. The organism
cannot plan to mutate in a particular way, although there
are some factors that may promote a high mutation rate in
times of severe trouble.

    Dr. David Campbell
    Old Seashells
    University of Alabama
    Biodiversity & Systematics
    Dept. Biological Sciences
    Box 870345
    Tuscaloosa, AL 35487-0345 USA
    bivalve@mail.davidson.alumlink.com

That is Uncle Joe, taken in the masonic regalia of a Grand
Exalted Periwinkle of the Mystic Order of Whelks-P.G.
Wodehouse, Romance at Droitgate Spa

                 
Received on Tue Mar 23 13:37:27 2004