Sharp Arguments Against Creationists
"I personally cannot discern a shred of evidence for '[intelligent] design' [of the universe]. If 97% of all creatures have gone extinct, some plan isn't working very well."
--- Harvard anthropologist Irven DeVore, speaking at a conference on "Cosmic Questions" at the Smithsonian Institution in Washington D.C., April 1999, sponsored by the AAAS and the Templeton Foundation (reported in Science 284: 737, 1999).
On this page I will occasionally drop in some ideas and facts from molecular biology and other parts of science that show errors in creationist thinking. I intend these to be "sharp arguments", meaning that once one understands them, there is no going back. You, of course, will be the judge of that!
See also the AntiCreationist page.
Can There Be Self Assembly?
There is a creationist argument,
due to William Paley
(1805, Natural Theology. Late London ed. New York: American
Tract Society)
that a watch won't assemble
itself from its parts. Are you familiar with the fact that bacteriophage T4
will do this? Bill Wood did some elegant experiments years ago on this
(W. B. Wood Bacteriophage T4 assembly and the morphogenesis
of subcellular structure. Harvey Lect.
753: 203-223, 1979.) He
got headless mutants. He got tailless mutants. (They were suppressors,
probably amber, so he could grow them on an amber suppressor bacterial
strain. A suppressor strain contains a modified tRNA that reads amber stop
codons.) He made extracts from the headless and tailless mutants. Alone they
could not infect, but if you mixed them they would self-assemble and then be
infective! He figured out an entire pathway of assembly from this method.
So it is possible for things to self assemble, especially
at the molecular level.
A picture of the assembly pathway is
in
REVIEW: Chaperones in Bacteriophage T4 Assembly,
Figure 1.
T4 pages:
Question:How does one know when a result is due to such basic molecular binding forces, as opposed to something else?
--- Matt Insall (montez@rollanet.org)
1999 July 20
Since the entire sequence of T4 is now known, we have the sequences of all the parts of T4. One could make non-binding mutants in the proteins and sequence them to determine which amino acids are involved in the binding interface. One could get x-ray crystal pictures of the parts and see that they fit together nicely. (For the scientist this means that on the surfaces of the two molecules positive charges should match negative charges, van der walls surfaces are aligned, cysteines are covalently linked, hydrophobic pockets match hydrophobic residues, etc.) Then I would expect many of the mutants to be in the interface surface. I doubt that this has been done for all or even a few interfaces for T4 (it is not such a hot field these days!) but similar things have been done for zillions of other interfaces. (Look up fibritin in pubmed for an example. The latest is Biochemistry (Mosc) 1999 Jul;64(7):817-23 The carboxy-terminal domain initiates trimerization of bacteriophage T4 fibritin. Letarov AV, Londer YY, Boudko SP, Mesyanzhinov VV)
A few days after answering this question, I came across this beautiful example: Proteins 1987;2(4):273-82 , Clustering of null mutations in the EcoRI endonuclease. Yanofsky SD, Love R, McClarin JA, Rosenberg JM, Boyer HW, Greene PJ.
New explanation [2000 Feb 3]:
In this work, the enzyme EcoRI was used. This protein cuts DNA. If it
is free in a bacterial cell, it will destroy the cell's DNA. So how do
the bacteria live with it? They have another enzyme that modifies
the DNA at the same place that EcoRI cuts. So what these people did
was start with a bacterium that had neither enzyme. They put the gene
for EcoRI on a ring of DNA and then made random mutations in that ring.
This made variations of EcoRI. They then put the variations into cells
without any protection. Of course if the EcoRI still worked it would
kill the cells. So the only cells that survived had mutations in the
EcoRI.
The neat result is that they found two kinds of mutations.
One was at the surface between the protein and the DNA and the other was
at the protein-protein surface. This protein binds to itself, like
a yin-yang symbol 
.
The curved line where the two sides join is the "protein-protein"
interface, and this is were the second class of mutations appeared.
So here is a pretty experiment where most mutations were just where
one would expect, at the interface.
It demonstrates clearly that we understand
the molecular binding forces that Matt Insall was asking about.
Obviously generating such extensive data takes an incredible amount of painstaking work, but I'm sure you could find some other elegant ones (including the EcoRI/DNA cocrystal structure) in the Protein Data base. In particular, when I was searching for the EcoRI structure, I came across the structure of one of the subunit interface mutations Ed144 (i.e. probably Gly144) found in the above report. So this example is getting nailed down very solidly.
The God Hypothesis violates Occam's Razor.
Occam's Razor says that the simplest explanation
should be preferred over a more complex one.
Using the concept that god created living things
fails because it is not the simplest hypothesis.
Indeed, it doesn't explain anything, only puts the problem off.
Where did God come from? This is invariably ignored,
or the response is that s/he was always there.
The counter response is that one could claim that
living things were always there, and at least we can
conclusively demonstrate that they have been around
for some billion years or more.
Where did all this come from?
God.
Where did god come from?
S/He was always there.
can be reduced to
Where did all this come from?
It was always there.
The latter may not be right, but it is simpler. Indeed, 'it was always
there' fits ideas by Hawking, but is not satisfying and there are theories of
larger spaces that our universe is in, but then that just puts the question
back further ...
Are Proteins Too Complex To Evolve? There is an old creationist argument (from L. M. Spetner, Natural selection: an information-transmission mechanism for evolution, J Theor Biol, 7, 412-429, 1964 and H. P. Yockey, A calculation of the probability of spontaneous biogenesis by information theory, J Theor Biol, 67, 377-398, 1977) about life being improbable. This is where someone claims that the probability of forming even one protein is astronomical (and therefore there had to be a designer).
The argument goes like this. A protein is made out of about 300 amino acids. There are 20 kinds of amino acid, so the number of possible proteins is 20300. That number is so big it would be impossible to explore only a portion of the possible proteins. So getting the first protein to function is impossible by generation of a random sequence.Only recently (around 1998) did I pinpoint the reason this is wrong.
Spetner computed his number by multiplying the probabilities of getting each base independently of each other base in the sequence. His number is the probability of getting everything just right in a single random shot.
But as everybody learns in school, only independent probabilities can be multiplied. Every step in the evolution of a protein is dependent on the previous steps. Therefore it is incorrect to multiply amino acid probabilities, and the computation is wrong. Selective processes can work with even a slight advantage and as many computer simulations show will rapidly converge on a good solution. This has spawned the field of designing things like airplane wings by selective processes.
A simulation of the evolution of information in molecular systems also demonstrates that that Spetner's computation was incorrect.
There are two stories: There's one and two. In Genesis, first chapter, God created the earth, then he created all the other animals, then he created man and woman. In the second chapter, he created the earth, then he created Adam, then he created all the other animals, then he created Eve. Now, if we're going to take the Bible literally, we're going to teach creationism, which version do we teach and who decides?
A human designing a computer program is free to incorporate improvements from programs developed by other humans in other parts of the world. On the other hand, this is precisely what we do *not* see in biological systems. (Horizontal transfer does occur, but not separated by space and time.) The genome of humans does not include evolutionary improvements discovered by flowering plants, for example. If today's biological diversity is the product of "intelligent design", it is entirely remarkable that this designer chose to make life appear to be arranged in a branching hierarchy consistent with common descent, without incorporating improvements across different branches. If life is designed, why does it look so much as if it evolved?
Tom Schneider's Home Page
T4 Image