Genetic algorithms are claimed to demonstrate that evolutionary processes
can create design, but in such algorithms, the design is smuggled in in
the form of the fitness function. Evolutionary algorithms do not create
specified complexity.
The fitness function of genetic algorithms need not include any new
information. A fitness function can be expressed as whether the
algorithm performs better or worse in a particular environment. The
only information is provided by the environment, which is usually
modeled on the real world. The claim makes sense only if design is
defined as what is in nature already.
One may argue that nature and design are inseparable (and Dembski seems
to make just such an argument; Dembski 2002, xiv), but this invalidates
the design argument. Design only has meaning if contrasted with
nondesign, and defining design as all of nature makes nondesign
nonexistent.
Genetic algorithms often come up with novel solutions which sometimes
even surpass direct human designs (Koza et al. 2003) and which do not
rely on human expertise (Chellapilla and Fogel 2001). Humans may have
told the algorithms what to do, but it is the how that defines the
design.
Genetic algorithms are not perfect evolutionary simulations in that
they have a predefined goal which is used to compute fitness.
They demonstrate the
power of random variation, recombination, and selection to produce
novel solutions to problems, but they are not a full simulation of
evolution (and are not intended to be). In simulations of biological
evolution, fitness is evaluated only locally; survival and reproduction
is based only on information about local conditions, not on ultimate
goals. However, the simulations demonstrate that distant fitness peaks
will be reached if there are conditions of intermediate fitness (Lenski
et al. 2003). Evolutionary processes do not "search." They respond
to local fitness topography only. The fact that evolution
(occasionally) reaches fitness peaks is a by-product of evolving on
correlated fitness landscapes using purely local fitness evaluation,
not an intended outcome.
