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These are excerpts and elaborations from my book "The Nature of Consciousness"
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Design With a Designer The complexity of life, as
we observe it today, is such that the Darwinian mechanism alone may not be
enough to explain how it evolved (in fact, Darwinhimself thought so, and
introduced sexual selection next to natural selection). There might be other
processes that help species evolve. The US chemist Michael Beheis skeptical about Darwin's theory of evolution because cells are too complex to have evolved
spontaneously. Most cellular systems are "irreducibly complex", i.e.
they could not work without some of their parts. If one of the parts is not
there, the system does not operate, and therefore cannot reproduce and evolve. Such systems cannot be built
by gradual evolution: too many of their parts must be there in order for them
to be able to start evolving. Their structure cannot be due to evolution
because their function cannot be built incrementally. For example, a mousetrap
is a mousetrap as long as it has a spring: a mousetrap with the spring cannot evolve
from a mousetrap without a spring because the latter would have no function,
therefore would simply not survive. Organisms are even more
complex than mousetraps: they require sophisticated mechanisms for storing and
transporting enzymes and proteins, among other things. The cell is too
complicated, and it needs to be that complicated in order to be a living cell,
and therefore it cannot have evolved from something that was less complicated. Ultimately, Behe's argument is that intermediate stages of evolution do not have
intermediate payoffs, and the evolution towards a self-sufficient system with
an evolutionary advantage is a sequence of such intermediate stages. The
chances that life survives so many intermediate stages are basically zero. Behereformulates the main objection against Darwinism: how is it
possible that complex organisms "evolved", if their parts must be
present all at the same time for the organism to work properly? An eye without
the retina is not much use. Even an eye with a retina but without the proper
connection to the brain is not much use.
All these things have to evolve at the same time in order for an
organism to be able to see, or eat, or walk. It is hard to believe that by
chance alone something as complex as a living organism would be created. Behebelieves that life must have
been designed by an intelligent agent, but, of course, there may simply be
other laws at work besides the basic Darwinian laws. An eye cannot arise suddenly
from an eye at all (the odds are on in billions). An eye may arise from
something slightly different from an eye. And this "something" may
arise from something slightly different from itself, and so forth. This sounds
a whole lot more plausible, but: 1. At each step of the "arising" a
stable system must be generated ("stable" as in "capable of
surviving and reproducing"); and 2. That system must survive long enough
to reproduce, otherwise there would be no further evolution. In order for
"homo sapiens" to arise, billions of small evolutions must have
occurred in all of our organs. The odds are indeed very low. It is debatable
whether there has been enough time (i.e., if two billions of years are enough)
for these very unlikely events to have occurred. As a matter of fact, a number
of biologists began searching for the "accelerator" that may explain
how evolution of such complex organisms can occur in such a "short"
time and with such efficiency (again, Darwinhimself had done so when he
introduced sexual selection). The US biologist Howard
Patteewas skeptic too, based on the
simple observation that Darwin's blind variation in a virtually infinite search space is inadequate
to explain the amazing rate of success at creating species that actually
survive. The
British biologist Richard Dawkinsanswers Behes objection
with a simple argument: even the most sophisticated organ is far from being
perfect. We perceive only a fraction of the world. Our eyes don't see and our
ears don't hear most of what is out there. Even the animals with the sharpest
senses miss some frequencies. We are easily fooled by a sound or a picture. In
other words, we "think" that we are such admirable beings, but the
truth is that we are precisely one of those imperfect, partial realizations
that Behe views as unlikely. Dawkinspoints out that numerous
"innovations" were forgotten by nature just because they did not get
transmitted. Our organs, far from being the best possible of each kind, are
merely (my definition) "what survived of what arose". Back to the beginning of the chapter "The Evolution of Life: Of Designers and Design" | Back to the index of all chapters |
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