[net.religion] Statistics and Evolution

david@ssc-vax.UUCP (05/07/84)

[*]
David Palmer:

>    David Norris has been trying to refute chance evolution using
> numerical arguments.  However, his methods aren't worth a pair of fetid
> dingo's kidneys.

Is this a conclusion or a premise? :-) I offered the few paragraphs that some
enlightened soul could lend some facts that back up or refute them.  These are
not "my" methods.

Dave goes into a discussion of the primordial soup which, I confess, is way
over my head.  I've since purchased a book called "Chemical Evolution", by
S. E. Aw (Head of Dept. of Nuclear Medicine at Singapore General Hospital).
If I can ever make any sense of it, I'll post to net.origins (a group which
I have avoided).

But what's really confusing, is that after using statistics himself, this
paragraph comes out:

> One objection creationists make is that the chances of creating the
> genes to make a man by this process are as close to zero as makes no
> never mind.  This is an incredibly subtle and stupid argument.  The
> chance that your parents' different sperm and ova came together in just
> the right way to create you are incredible, and if you combine that
> with the probabilities of your grandparents' sperm and ova... etc.
> etc., etc.  I can rapidly run up the odds to one in googles of googles
> of googles of... so that it is as close as spitting to impossible that
> you exist.  The fact that you do exist is due to an incredible
> coincidence.  (You can blame it on G-d if you want, but I don't).

Something is very fishy about this line of reasoning, but it was hard to put
my finger on it.  I think it is a gross mis-use of analogy.  Determining odds
that a particular person called Dave Norris could exist can be as incredible as
we want to make it.  As you say, just combine probabilities as far back as
you care to.

Does this refute Boa's argument?  I don't think so.  He didn't extend the
probabilities back to "up" the chances of the event not happening.

Now, given enough time, the primordial soup will come up with something we call
"life".  The time factor is the real problem; the earth is only 4.5B years old,
and some scientists have placed the first life at about t+1B years.  That's
one billion years for the primordial soup to do it's stuff.  Statistics tell
us the probabilities for chance formation of life (in 1 billion years) is
extremely low.  Not impossible, but highly, highly unlikely.

>    Just as an aside, the time it would take these million fast-typing,
> never-sleeping monkeys to type the first four words of one of
> Shakespeare's plays is about 1E24 years (one septillion for North Americans,
> one quadrillion for the British).  If you can't trust Boa & Moody on
> simple calculations, why should you trust them on the origin of life.

Here is the text from Boa & Moody:

: Let's consider George Bernard Shaw's argument that if a million monkeys
: constantly typed on a million typewriters for a long enough time, one of them
: would eventually pound out a Shakespearean play.  Assume a million monkeys
: typing 24 hours a day at 100 words a minute on typewriters with 40 keys.  If
: each word of the play contained 4 letters, the first word would be typed by
: one of the monkeys in about 12 seconds.  However, it would require about five
: days to get the first two words (eight letters) on one of the typewriters.
: How long would it take to get the first four words? About 100 billion years!

It seems to me that your statement simply contradicts Boa's.  Did you compute
this yourself, or get the figure from another text?  Could you give equations
or references, repectively?

	-- David Norris        :-)
	-- uw-beaver!ssc-vax!david

palmer@uw-june.UUCP (05/08/84)

<Here we are in the finals of the table tennis tournement.  David
Norris is serving using a Boa paddle, David Palmer returns :-)>

My statements are preceeded by ">>", David Norris' comments are
preceded by ">"


>> One objection creationists make is that the chances of creating the
>> genes to make a man by this process are as close to zero as makes no
>> never mind.  This is an incredibly subtle and stupid argument.  The
>> chance that your parents' different sperm and ova came together in just
>> the right way to create you are incredible, and if you combine that
>> with the probabilities of your grandparents' sperm and ova... etc.
>> etc., etc.  I can rapidly run up the odds to one in googles of googles
>> of googles of... so that it is as close as spitting to impossible that
>> you exist.  The fact that you do exist is due to an incredible
>> coincidence.  (You can blame it on G-d if you want, but I don't).

> Something is very fishy about this line of reasoning, but it was hard
> to put my finger on it.  I think it is a gross mis-use of analogy.
> Determining odds that a particular person called Dave Norris could
> exist can be as incredible as we want to make it.  As you say, just
> combine probabilities as far back as you care to.
> 
> Does this refute Boa's argument?  I don't think so.  He didn't extend
> the probabilities back to "up" the chances of the event not happening.


Boa's argument included the idea that the chances of 400 amino acids
coming together to form a particular gene were near enough to zero that
no reasonable person would have expected it to happen.  However, the
probability of 400 amino acids coming together to form some useful gene
is nowhere near as low.  The analogy is that the chance of forming
David Norris is low, but the chance of forming something (somebody
else, or maybe a tree) is quite high.


> Now, given enough time, the primordial soup will come up with something
> we call "life".  The time factor is the real problem; the earth is only
> 4.5B years old, and some scientists have placed the first life at about
> t+1B years.  That's one billion years for the primordial soup to do
> it's stuff.  Statistics tell us the probabilities for chance formation
> of life (in 1 billion years) is extremely low.  Not impossible, but
> highly, highly unlikely.


There is still some debate about when the first life was formed, but
most paleontologists do agree that it had occurred by t+1B years.
Conditions were changing rapidly then, and it is still not clear
whether life occurred within a few millenia of it becoming possible, or
after some longer or shorter delay.

Statistics DO NOT tell us that the probabilities for chance formation
of life (in 1 billion years) is extremely low.  People who use certain
assumptions (1 chance in a hundred that an amino acid will link with
another, you need 400 amino acids placed in just the right order to
achieve life, linkage of amino acids occurs on a purely random basis,
with no selection effects, etc.) use statistics to tell you that the
probability for chance formation of life is extremely low.  People who
use other assumptions (you only need about 10 amino acids to acheive
self-replication (auto-catalysis), amino acid chains can link together,
amino acid chains have a higher probability of linking to other chains
with the same chiral parity (handedness) etc.) use statistics to tell
you that life is quite likely, especially with 3E16 seconds (1B years)
and 2E42 molecules (a world ocean 100m deep) to play with.


>>    Just as an aside, the time it would take these million fast-typing,
>> never-sleeping monkeys to type the first four words of one of
>> Shakespeare's plays is about 1E24 years (one septillion for North Americans,
>> one quadrillion for the British).  If you can't trust Boa & Moody on
>> simple calculations, why should you trust them on the origin of
>> life.

> Here is the text from Boa & Moody:

>:Let's consider George Bernard Shaw's argument that if a million monkeys
>:constantly typed on a million typewriters for a long enough time, one of them
>:would eventually pound out a Shakespearean play.  Assume a million monkeys
>:typing 24 hours a day at 100 words a minute on typewriters with 40 keys.  If
>:each word of the play contained 4 letters, the first word would be typed by
>:one of the monkeys in about 12 seconds.  However, it would require about five
>:days to get the first two words (eight letters) on one of the typewriters.
>:How long would it take to get the first four words? About 100 billion years!

> It seems to me that your statement simply contradicts Boa's.  Did you
> compute this yourself, or get the figure from another text?  Could you
> give equations or references, repectively?


I'm afraid I fell down on this one.  I assumed that the average word
contains 5 letters, and is followed by a sixth character (a blank, a
punctuation mark, etc.)  Thus four words of Shakespeare, on average,
would require 24 keystrokes.

However, I forgot to take into account the large variability in the
length of words.  The shortest opening four words I've found in
Shakespeare is the opening of _Pericles_: "To sing a song that old was
sung..." with 11 letters, three spaces, and a shift.  In order to make
the random typing into words, you also need a space at the beginning
and the end.  This is 16 characters (including the spaces) and a shift
(which would probably require hitting the shift lock, hitting the T
key, and then either of the two shift keys.)  This, to within a few
orders of magnitude, gives Boa's result.

The moral of this is: It doesn't take so long after all.  If it takes
only 100 billion years for a million trained monkeys to write the first
four words of a play (although it is one of Shakespeare's lesser works
:-))  then it is not suprising that 2E42 molecules, helped by natural
selection, took only 3E16 seconds to create life.

                David Palmer