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Miroslav Radman                                                                                                                                          © 2001 Macmillan Magazines Ltd
The apparent perfection of organisms
and the accuracy of biological processes
are still used in religious explanations of
the origin of life. However, in real life it is sur-
vival, not fidelity, that is the ultimate virtue.
Because adaptability involves exploration
of genetic possibilities to fit ecological niches,
replication, accuracy is achieved by using a
‘proofreading’ system to remove erroneous-
ly inserted nucleotides, and then by quality-
checking the synthesized DNA using a
mismatch-repair system that removes
virtually all remaining mistakes. It would
take too long to get it exactly right in the first
place. DNA replication is efficient and
therefore relatively imprecise....