Irreducible Complexity and Michael
Do Biochemical Machines Show Intelligent
n 1996, the Free Press published a
book by Lehigh University biochemist and intelligent design
Darwin's Black Box: The Biochemical
Challenge to Evolution. The book's central thesis is
that many biological systems are "irreducibly complex" at
the molecular level. Behe gives the following definition of
By irreducibly complex I mean a single
system composed of several well-matched, interacting parts
that contribute to the basic function, wherein the removal
of any one of the parts causes the system to effectively
cease functioning. An irreducibly complex system cannot be
produced directly (that is, by continuously improving the
initial function, which continues to work by the same
mechanism) by slight, successive modifications of a
precursor system, because any precursor to an irreducibly
complex system that is missing a part is by definition
nonfunctional. An irreducibly complex biological system, if
there is such a thing, would be a powerful challenge to
Darwinian evolution. (p. 39)
Although the argument from irreducible complexity is
essentially a rehash of the famously flawed
watchmaker argument advanced by William
Paley at the start of the 19th century, Behe's book has
attracted a great deal of attention from creationists and
non-creationists alike. The articles collected here address
the claims made by Behe in his book.
- The Mullerian Two-Step: Add a part, make it necessary
(or, Why Behe's "Irreducible Complexity" is Silly)
- A simple and concise explanation for why the anti-evolutionary argument from "irreducibly complexity" is flawed — gradual evolution by natural selection readily evolves "irreducibly complex" structures.
- Darwin's Black Box:
Irreducible Complexity or Irreproducible
- Keith Robison reviews Michael Behe's book Darwin's
Black Box, which claims that many biological systems
are "irreducibly complex" — that in order to evolve,
multiple parts would have to arise simultaneously. But is
- Publish or Perish:
Some Published Works on Biochemical Evolution
- This list of papers has been collected in response to
Michael Behe's claim that the scientific literature is
virtually silent on the topic of molecular evolution.
- Behe's Criticism
of Evolution in Biochemistry Textbooks
- In addition to claiming that the scientific literature
devotes no time to questions of molecular evolution,
Michael Behe has also said that the same is true of college
biochemistry textbooks. Here, the author of some of the
textbooks Behe has reviewed demonstrates this claim to be
- Is the Complement
System Irreducibly Complex?
- One of the molecular assemblages that Michael Behe
claims is "irreducibly complex" is the complement system,
an arm of the vertebrate immune system so named because it
"complements" the effect of antibodies. This essay outlines
the functioning of the complement system and undercuts
Behe's argument by showing that simpler yet still
functional versions of it exist in nature.
More articles about irreducible complexity and intelligent design can be found at
the sister site of The Talk.Origins Achive, Talkdesign.org:
Critically Examining the "Intelligent Design"
- This FAQ shows that molecular
evolution is much too flexible for
IC to be an
obstacle, shows that Behe's argument is fallacious, and using Venus' flytrap
shows that the mousetrap analogy is misleading.
A Response to Chapter 6 of Darwin's Black Box
- Reviews immune systems of various animals and finds that
their complexity is not the intractable problem that Behe
would have us believe.
Evolution in (Brownian) Space:
A Model For the Origin of the Bacterial Flagellum
- Michael Behe, William Dembski, and other intelligent
design advocates claim that the bacterial flagellum is
too complex to have evolved. This article proposes a possible
step-by-step model for the evolution of the flagellum. This
article is rather technical and thus has a
background file that links to introductory material,
articles by intelligent design advocates on the flagellum, and
rebuttals to their arguments.
Two documents in this Archive have a subsection addressing
Behe's claims about irreducibly complex features:
- Applying the Method to Nature:
- Discusses how Behe's fellow intelligent design advocate William
Dembski uses irreducibly complex arguments in his book
No Free Lunch. Part of
Not a Free Lunch But a Box of Chocolates.
Suboptimality and Irreducible Complexity
- Discusses the implications of suboptimal biological features
on Behe's argument.
Part of 29+ Evidences for Macroevolution.
The Quote Mine Project
examines some of the quotes used by Dr. Behe.
Orr and Coyne unexpectedly find that there is little evidence for the neo-Darwinian
John McDonald thinks that research on the genetic basis of adaptation has led
to a great Darwinian paradox
Behe, Darwin's Black Box, and irreducible complexity
are the subject of two winning posts and one runner-up post of the
Post of the Month contest of the
talk.origins newsgroup which are
archived in this web site.
- February 1997:
Behe and the Blood Clotting Cascade
- December 1999:
Behe, the Krebs Cycle, and Models of Origins of Complex Biochemical Structures
- October 2003 runner-up:
Why Behe's Black Box Is Empty
- September 2006:
Irreducible Complexity as an Evolutionary Prediction
This Archive also has a copy of Behe's
testimony at the Kansas Evolution Hearings
and his trial testimony at
Kitzmiller et al. v. Dover Area School
District et al.
Short rebuttals to many arguments made by Behe and other intelligent-design advocates
can be found at the molecular biology
and detecting design sections
of an Index to Creationist Claims.