[2005/04/04] Flagellum Described in High-Performance Lingo
Flagellum Described in High-Performance Lingo 04/04/2005 The bacterial flagellum, a
virtual icon of the intelligent design movement, has been studied by many
researchers, notably Howard Berg of Harvard, an expert on chemotaxis (the
attraction of bacteria to chemical stimuli). Berg was interviewed in
Current Biology1 and talked like a race car mechanic
when discussing this molecular machine, though he is not involved in the
ID movement and believes in evolution. Here are some excerpts:
The modern era [of chemotaxis studies] began in the 1960s with
Tetsuo Iino and Sho Asakura in Mishima and Nagoya, who began work on the
structure of flagellar filaments (thought then to be primitive
bending machines)...
the flagellar motor has several pistons and a novel
torque-speed relationship....
We hope to understand how bacterial chemotaxis works, every nut and
bolt. Who would have imagined: receptor complexes that
count molecules and make temporal comparisons; activation of
a diffusible signal that couples receptors to flagella;
reversible rotary engines that drive propellers of variable
pitch; force generators, rotors, drive shafts, bushings, and
universal joints; a system with prodigious sensitivity, with
amplification generated by receptor-receptor interactions?
The biggest black box is the motor. We know a great
deal about its electromotive and mechanical properties
(torque, speed, changes in direction, and so forth) but we do not
really know how it works. We need more structural
information. This is hard, because essential components are
membrane embedded. But even in an age of systems biology, one
should not be embarrassed to focus on an isolated network
controlling a particular molecular machine.
(Emphasis added in all quotes.)
1Q&A: Howard Berg, Current
Biology, Volume 15, Issue 6, 29 March 2005, Pages R189-R190,
doi:10.1016/j.cub.2005.03.003.
And yet he says, “Chemotaxis evolved so
that cells can locate nutrients....” Who would have imagined,
indeed. But then, when entering the high-performance world of
microtechnology, imagination is what keeps the evolutionary story
lubricated. Alcohol helps, too; some evolutionists seem to have converged on that form of
chemotaxis after watching Unlocking the Mystery of
Life.
[2005/04/04] Flagellum Described in High-Performance Lingo
