On Wed, 30 Aug 1995 23:29:49 -0400 Glenn wrote:
GM>ABSTRACT: The probability argument against the random finding of
>a given sequence is one of the main stays of the anti-
>evolutionary position. I have noted before that I view that
>argument as a weak one for a variety of reasons. In this note I
>will show that the finding of a functional sequence by a random
>search is quite likely on normal evolutionary time scales.
>Because of this, and other weaknesses in the traditional
>apologetic, Christianity needs to move to a more defendable
>apologetic.
I am not trained in biochemistry, so what I write is not to be
interpreted technically, but as how a layman sees it. I also don't
want to get into a protracted argument, so this may be my one and only
response on this topic. Others who are more competent in biochemistry
may want to take it up?
GM>Duane Gish once wrote:
>"The highly specific biological activity of each protein is due
>to the precise way the amino acids are arranged, just as the
>information conveyed by this sentence is determined by the
>precise sequence of 190 letters found in it."~Duane Gish, "The
>Origin of Life," Proc. First Int. Conf. on Creationism,
>Pittsburgh: Creation Science Fellowship, 1986, p. 62
GM>There is a major problem with that sentence. This is not the
>only way to state what Gish wanted to state. For instance, he
>could have written "Biological activity is due to very specific
>orderings of amino acids as this sentences meaning is due to the
>123 letter order."
This may not be the only way to state what Gish wrote *in English*,
but the point is that this is only an analogy. The same flexibility
may not be found even in other human languages? Also, the meaning of
Glenn restatement is meaningful only to an intelligent human mind.
In a protein, how many different ways are there to order amino acids
and still have the same result biochemically?
GM>This is only a hint of how much variability there is in sequence
>space in order to convey the same message. There is an amazing
>flexibility in the language to perform the same task. I once
>calculated that there are over 330,000 ways to convey the
>information, "if you pick your nose; you get warts."...
Glenn's "330,000" different ways of conveying the same message are
understandable only to the mind of a human who is experienced in
English. But no doubt many (if not most) are grammatically incorrect?
It may be that even small departures by proteins from rules of
biochemical "grammar" render them incomprehensible biochemically?
Also, are Glenn's "330,000 eays to convey the information" in his
message *exactly* the same in meaning? A test would be to give a
different one of the 330,000 alternatives to each one of (say) 990,000
different English-speaking people. Only if a statistically
significant number of them correctly re-translated it back into
Glenn's ancestral message, would Glenn's hypothesis be sustained.
After all, how many people would recognise:
"Being an individual of restricted verbosity, sesquipedalian
phraseology is unimpeachable against me"
as:
"I am a man of few words"! :-)
GM>So the question is, if I wish to convey a certain message, how
>likely is it that I can find a sequence to perform a given
>function? There is a way to randomly produce a useful sequence
>which is not all that improbable.
GM>Let's use a less gross example than the nose picking one above.
>Lets find a functional sequence to answer the question your wife
>asked you when you were first married. "What do you want for
>breakfast?" (and you thought I was going to say something else.
>tsk tsk.) There are lots of ways to answer this question. What
>we will do is choose a 70 unit long sequence of 20 letters,
>ruling out the use of z,q,x,k,v and j. Thus, we have in this 70
>unit long sequence 1.18 x 10^91 different possible combinations.
>Normally the anti-evolutionists say, like Gish, that the
>likelihood of finding just the correct sequence is too unlikely
>to occur. This is usually based upon the idea that one and only
>one sequence will perform the task. This is untrue as we have
>seen.
What we have "seen" is an *analogy* between English language phrases
and protein molecules. This is a vast oversimplification. Amino
acids are 3D in structure and both L- and R-handed. Only L-handed
amino acids occur in living things. As Bradley & Thaxton point out
(Moreland J.P. ed., "The Creation Hypothesis", 1994, p189), in the
analogy of writing the sentence "How DID LIFE BEGIN?", the following
problems would occur:
1. UPSIDE DOWN LETTERS "upside-down letters would represent D-amino
acids in the sentence mixed with L-amino acids"
2. SIDEWAYS LYING LETTERS "The problem that occurs when nonpeptide
bonds occuring our assembly of amino acid building blocks is
illustrated...The proper placement of letters adjacent to one another
has been altered so that some letters have irregular proximity to each
other..."
3. OUT OF SEQUENCE LETTERS "improper sequence is illustrated by taking
our original statement and rearranging some of the letters, totally
obscuring the original message."
4. ALL THREE SUPERIMPOSED If all three of these problems were
superimposed, the original message would be impossible to
decipher-there would be a total loss of function."
5. NOT ONLY ENGLISH LETTERS "The greatest problem, however, is how to
draw only English alphabet letters from an "alphabet soup" including
many English letters (representing amino acids) but also Chinese,
Greek and Hebrew symbols (representing other kinds of organic
molecules in the prebiotic soup) and get one each of H, O, W, L, F, B,
G, N; two D's and E's; and three I's."
It seems that Glenn's analogy only considers 3. above. It therefore
breaks down. The remainder of his comments, to the extent they are
based on this overly simplistic analogy, seem invalid.
[...]
GM>Do proteins act in the same fashion as the language above? Yes.
>Gerald Joyce is one of the leaders in the field of directed
>evolution. I would point you to Discover, May 1994, "Speeding
>Through Evolution,", and to Gerald E. Joyce, "Directed
>Evolution," Scientific American, Dec. 1992, pp.somewhere around
>p. 94,95 or Beaudry and Joyce, Science, 257:637-638, 1992.
>
>Sean Eddy of the Washington University School of Medicine
>recently wrote on Talk Origins,( message
><EDDY.95Aug17084136@wol.wustl.edu>) that RNA sequence space is
>teeming with interesting functionalities. All based upon Joyce's
>work.
There must be a difference of scientific opinion here:
Bradley & Thaxton:
"Neglecting the problem of reactions with non-amino acid chemical
species, the probability of getting everything right in placing one
amino acid would be 0.5 x 0.5 x .05 = .0125. The probability of
properly assembling N such amino acids would be .0125 x .0125 x . . .
continued for N terms of .0125. If a functional protein had one
hundred active sites, the probability of getting a proper assembly
would be .0125 multiplied times itself one hundred times, or 4.9 x
10^-l9l. Such improbabilities have led essentially all scientists who
work in the field to reject random, accidental assembly or fortuitous
good luck as an explanation for how life began." (Bradley & Thaxton,
p190)
and Denton:
"Although the exact degree of isolation and rarity of functional
proteins is controversial it is now generally conceded by protein
chemists that most functional proteins would be difficult to reach or
to interconvert through a series of successive individual amino acid
mutations....The impossibility of gradual functional transformation is
virtually self-evident in the case of proteins: mere casual
observation reveals that a protein is an interacting whole, the
function of every amino acid being more or less (like letters in a
sentence or cogwheels in a watch) essential to the function of the
entire system. To change, for example, the shape and function of the
active site (like changing the verb in a sentence or an important
cogwheel in a watch) in isolation would be bound to disrupt all the
complex intramolecular bonds throughout the molecule, destabilizing
the whole system and rendering it useless. Recent experimental
studies of enzyme evolution largely support this view, revealing that
proteins are indeed like sentences, and are only capable of undergoing
limited degrees of functional change through a succession of
individual amino acid replacements. The general consensus of opinion
in this field is that significant functional modification of a protein
would require several simultaneous amino acid replacements of a
relatively improbable nature. The likely impossibility of major
functional transformation through individual amino acid steps was
raised by Brian Hartley, a specialist in this area, in an article in
the journal Nature in 1974 From consideration of the atomic structure
of a family of closely related proteins which, however, have different
amino acid arrange- ments in the central region of the molecule, he
concluded that their functional interconversion would be
impossible..."
(Denton M., "Evolution: A Theory in Crisis", 1985, Burnett Books,
p320)
GM>Thus, the weaknesses in the traditional creationist probability
>argument is two fold. It assumes that one and only one sequence
>can perform a given function. And secondly, it assumes that only
>the most complex forms must be made at first. This ignores the
>potential of short sequences performing the same function."
[...]
GM>It is very obvious that the positions we are defending
>apologetically, are not very secure.
[...]
GM>But if the probability argument against evolution is
>as weak as I showed above, Christianity had best find a better
>way to handle the area of Science and the Bible.
No doubt much of Christian apologetics (particularly YEC) may be
overly simplistic, but I don't believe that Glenn has made his point.
If the spontaneous self-assembly of proteins from amino acids is not
so improbable why: 1. has such self- organisation of proteins from
amino acids not been observed in nature, and indeed, 2. been unable to
be arranged even in highly contrived simulations?
Davis & Kenyon:
"The success of such early experiments greatly increased the
credibility of evolutionary theory. But when scientists sought to go
beyond the simplest building blocks of life, the momentum slowed. The
step from simple compounds to the complex molecules of life, such as
protein and DNA, has proved to be a difficult one. Thus far, it has
resisted all efforts by the scientists working on the problem. The
problem is that some chemical reactions occur quite readily, whereas
others do not. The simple building blocks of life form relatively
easily. They form in reactions belonging to the classes that occur
readily. But the chemical reactions required to form proteins and DNA
do not occur readily. In fact, these products haven't appeared in any
simulation experiment to date."
(Davis P. & Kenyon D.H., "Of Pandas and People: The Central Question
of Biological Origins", Second Edition, 1993, Foundation for Thought
and Ethics, Richardson, TX, p3)
As I said, I don't want to enter a prolonged debate on this issue.
When science demonstrates the spontaneous generation of life from
non-life in a laboratory, even with the setting up of artificially
contrived conditions not found in nature and the direct application of
intelligent human design, then creationists might begin to be
impressed! :-)
God bless.
Stephen
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