Page 66 - The Evolution Impasse 2

64 Mutation: An Imaginary Mechanism

chan ges that are usu al ly too se vere MUTATION: AN IMAGINARY
for the cell to re pair. Cells or liv ing MECHANISM
things sub ject ed to such mu ta tions—
Mutations are breaks and shifts
99% of which are harm ful and the
that oc cur as a re sult of ra di o ac tive
oth er 1% neu tral or si lent— are
or chem i cal dam age to the DNA
known as mu tants. (See Mutation:
mol e cule that car ries ge net ic da ta.
An Imaginary Mechanism)
Mutations dam age the nu cle ot i des
Although mu ta tions have clear ly
that make up DNA, or else cause
de struc tive ef fects, ev o lu tion ists re -
them to change pla ces, caus ing chan -
gard ran dom mu ta tions oc cur ring in
ges that are usu al ly too se vere for
liv ing things' ge net ic struc tures as
the cell to re pair.
the source of the pos i tive ev o lu tion -
Therefore, con tra ry to what many
a ry chan ges that they as sume took
peo ple im ag ine, the mu ta tions that
place. Yet mu ta tions can nev er be -
ev o lu tion ists de pend on are not,
stow a new or gan or new char ac ter -
mag ic wands that lead liv ing things
is tic on a liv ing thing by add ing new
to progress and perfection.
in for ma tion to its DNA. They mere -
Mutations' net ef fects are harm ful.
ly cause ab nor mal i ties, such as (on a
The on ly chan ges brought about by
fruit fly) a leg emerg ing from the
mu ta tions are of the kind suf fered by
back of the in sect.
the off spring born to in hab it ants of
Can new in for ma tion emerge as
Hiroshima, Nagasaki or Chernobyl;
the re sult of mu ta tions? Professor
in oth er words, death or de form i ty.
Werner Gitt re sponds to the ques -
The rea son for this is el e men ta ry:
tion:
Any ran dom im pact on the very
This idea is cen tral in rep re sen ta tions com plex struc ture of the DNA mol e -
of ev o lu tion, but mu ta tions can on ly
cule can on ly harm it.
cause chan ges in ex ist ing in for ma tion.
The American ge net i cist B.G.
There can be no in crease in in for ma -
Ranganathan ex plains:
tion, and in gen er al the re sults are in -
First, gen u ine mu ta tions are very rare
ju ri ous. New blue prints for new func -
in na ture. Secondly, most mu ta tions
tions or new or gans can not arise; mu -
are harm ful since they are ran dom,
ta tions can not be the source of new
rath er than or der ly chan ges in the
(cre a tive) in for ma tion. 63
struc ture of genes; any ran dom change
in a high ly or dered sys tem will be for
the worse, not for the bet ter. For ex am -
The Evolution Impasse II