Biochemical Challenge

Tim Ikeda timi at mendel.berkeley.edu
Sat Nov 9 03:30:50 EST 1996

Missing from the book was any serious attempt at outlining the
comparative biochemistry of the systems discussed.  The examples
of "irreducibly complexity" are generally presented without
reference to when they might have arisen and what variations
are found in other, related organisms.  While sequence
similarities are noted and accepted (as evidence of common
descent) there is not much discussion about what these
similarities might suggest about the path of evolution.
Thus, while we are treated to examples of how important
the proper function of the blood clotting cascade is for us
today, the discussion tells us nothing about the organisms
in which the clotting system first arose.  Without better
knowledge of what happens other organisms, I do not see how
evolutionary transitions could possibly be proposed (or
modeled) at the level of detail Behe wants.  FWIW, I'm not
sure the best characterized systems of existing organisms
could be modeled and at the level he proposes.

The book was pretty fair at presenting what isn't known about
the evolution of complex systems, but was a bit empty when
discussing the relationships between systems in different

Now, Michael Behe maintains that many biochemists are actually
shocked (or at least surprised) when told how little progress
has been made in understanding the step-by-step evolution
of biochemical systems.  If true, then yes, I think the book
could help in shaking some biochemists awake.  But I wonder
if most of us are actually not shocked by this revelation.

Tim Ikeda (timi at mendel.berkeley.edu)

More information about the Mol-evol mailing list

Send comments to us at biosci-help [At] net.bio.net