david@ssc-vax.UUCP (04/29/84)
"mwm" (sorry, no name): > I haven't run into anybody who is particularly bothered by the fact that > there may not have been anything before the Big Bang (Event 1). I > personally favor the cyclic theory, which says that before Event 1, there > was another universe that expanded and then recontracted back to the cosmic > egg. No problems with a Beginning there. What about reversing Entropy? > Last time I looked, the most reasonably sounding hypotheses what the the > basic living organisms (viruses and on down) got together in the cloud of > shit (Sorry, but fertilizer doesn't sound right) that the Earth formed > from. Given that they keep finding newer and more complex organic molecules > in *interstellar* dust clouds, almost anything could pop up down here where > THE STUFF GETS THICK. [emphasis mine - DCN] I'm not going to touch this one! Seriously, the last paragraph provides a response. > Your definition of miraculously low and mine differ. Given a universe to > play with, the probability of life forming somewhere indistinguishable from > one. (ok - I confess, I didn't do the calculations. If you insist, I will. > But you'll have to settle for a rough estimate. Everything I can calculate > with gets upset when you get beyond a few thousand digits.) I suspect that > a relatively small chunk of the universe, like a galaxy. Rough guess: > given that there is one chance in a billion for life to form on a planet, > and that there is roughly one planet per star (very rough guess, and low by > current estimates), the probability that there is somewhere in the galaxy > (discounting us) is: .99995. See? Big numbers easily make up for small > probabilities. The following is taken from Boa & Moody's "I'm glad you asked." I offer it in the hope that some informed soul can shed some light on its veracity. "One chance in a billion" is peanuts compared to the numbers we should be talking about: "Beginning with the first step, many evolutionists assume a primordial earthly atmosphere with no oxygen so that amino acids could be formed. However, the very atmosphere that could produce them would immediately lead to their destruction (due to ultraviolet light penetrating this oxygen-free atmosphere) unless they were protected. Unfounded assumptions must be multiplied to overcome this problem. On the next level, let us assume an ideal environment with a primordial soup full of amino acids and the proper catalysts, with just the right temperature and moisture. Some estimate that under these favorable conditions the chances of getting dipeptides (two amino acids bonded) would be about 1 in 100. But the chances of tripeptide formation would be about 1 in 10,000. To get a polypeptide of only 10 amino acids, the probability would be 1 chance in 100,000,000,000,000,000,000 (100 quintillion). Yet the proteins in the simplest living things have chains of at least 400 amino acids on the average. To make matters worse, all proteins are built of amino acids that are exclusively "left-handed" in their molecular orientation. Left-handed and right-handed amino acids are mirror images of each other, and the chances of formation are about the same. Although both kinds can link with each other, the first living systems must have been built with left-handed components only. Some scientists have evoked natural selection here, but this only applies to systems that can already reproduce themselves. Without an intelligent ordering agent, we have only chance to explain this amazing phenomenon. For a chain of 400 left-handed amino acids, the odds would be roughly equivalent to tossing an ordinary coin and coming up with tails 400 times in a row. The chances for that would be approximately 1 in 10^120 ( a 1 followed by 120 zeroes). All this for *one* protein molecule, and hundreds of similar molecules would be needed in the first living system. None of this accounts for the fact that the 20 kinds of amino acids operate like letters in an alphabet, and they must link in a meaningful sequence to form a usable protein. A random sequence of amino acids would be utterly useless. DNA is far more complex than any of this, and it too is built out of a highly organized alphabet. The letters are molecules called nucleotides. A cell contains a chain of about three billion pairs of these nucleotides (each gene has about 1,200 nucleotide pairs). The order of these nucleotides or bases is crucial because every triplet of bases along this immense chain is a word. Each word stands for one of the 20 kinds of amino acids. Using these words the DNA can literally create any kind of protein the cell needs. The amount of time required to synthesize even one gene (a paragraph of these words) has been calculated by some scientists using absurdly generous assumptions. Using a variation on a well-known illustration, suppose a bird came once every billion years and removed only one atom from a stone the size of the solar system. The amount of time required for the stone to be worn to nothing would be negligible compared to the time needed to create a useful gene by chance, even accounting for chemical affinities and an ideal environment. Shaw's monkeys would long since have pounded out the words of Shakespeare!" Earlier in the chapter, it was noted that the time required for 1 million monkeys typing at 100 words/minute, 24 hours a day on typewriters with 40 keys to type the first four words of a Shakepearian play would be about 100 billion years. I am not a "creationist", as I understand that term. But it is impossible for me to see how man could have evolved from chance. -- David Norris :-) -- uw-beaver!ssc-vax!david
palmer@uw-june.UUCP (05/01/84)
fnord
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.
His argument is taken from Boa & Moody's "I'm Glad You Asked", so I
guess he does not really deserve all the blame :-). Boa & Moody is
indented, my reply is not
"Beginning with the first step, many evolutionists assume a primordial
earthly atmosphere with no oxygen so that amino acids could be formed.
However, the very atmosphere that could produce them would immediately
lead to their destruction (due to ultraviolet light penetrating this
oxygen-free atmosphere) unless they were protected. Unfounded
assumptions must be multiplied to overcome this problem.
It is quite reasonable to assume a primordial Earth atmosphere with no
oxygen. Oxygen is quite reactive, and before photosynthetic plants
arrived, there was little enough being produced (through photolysis,
volcanoes, etc.) that it rapidly combined with other chemicals.
Ultraviolet light may be able to penetrate the methane, nitroxides,
etc. which made up the original atmosphere, (I do not know, I do not
have a table of UV transmission coefficients here) but it wouldn't be
able to penetrate ordinary clouds, which were probably abundant, or a
few inches of water. An "unfounded assumption" would be that life
could only evolve at the surface of the land or water, on sunny days.
On the next level, let us assume an ideal environment with a primordial
soup full of amino acids and the proper catalysts, with just the right
temperature and moisture. Some estimate that under these favorable
conditions the chances of getting dipeptides (two amino acids bonded)
would be about 1 in 100. But the chances of tripeptide formation would
be about 1 in 10,000. To get a polypeptide of only 10 amino acids, the
probability would be 1 chance in 100,000,000,000,000,000,000 (100
quintillion). Yet the proteins in the simplest living things have
chains of at least 400 amino acids on the average.
I don't understand this estimate. Does it say that for any amino
acid, there will be a 1% chance of getting a dipeptide? Or does it say
that if you have a planet covered with the stuff, there will be one
chance in a hundred of there being a dipeptide? And is that while the
soup is in equilibrium, or is that after a time of one second, day,
year, eon, or cosmic cycle?
Lets assume that the estimate means that, in equilibrium, for every
100 amino acids, there is one dipeptide. Suppose that, in order for
self-replication, to occur, you need a PARTICULAR string of ten amino
acids.
This is probably being very generous to the creationists.
First of all, if there is one self-replicating molecule of some length,
there are probably many. Secondly, the shortest self-replicating
molecule may be shorter than ten amino acids long. The simplest
self-replicating substance I know of is an obscure molecule which
scientists call "water" (chemical symbol: H2O). If you take a glass
bulb filled with two parts by volume of hydrogen and one part by volume
of oxygen, and you heat it to a few hundred degree Celsius, you'll
probably become bored when nothing happens. If, however, you introduce
a few droplets of water into that heated mixture, the little blighters
will really go to, and when their procreative energy finally abates
and the orgy ends, you'll find yourself picking pieces of wet glass out
of the scorched walls of the room. (If you were in the room at the
time, then you got what you deserved, you peeping-Tom pervert, but my
condolences to your family. If you survived, then agian, my condolences
to your family :-)
I would not call water molecules alive, but the person who estmated
the 1/100 number for dipeptides would probably give a somewhat lower
number for the chance of hydrogen and oxygen coming together.
Anyway, let us see if this particular string of ten amino acids has
any probability of occuring.
Firstly, there are 20 amino acids, and the chance of a link-up to
any amino acid is 1/100. Therefore, the chance of linking up with the
right amino acid is 1/(20*100), if you add handedness, then the chances
of linking to the right type are 1/(2*20*100). The chance of getting
ten successsful link-ups to the right amino acids of the right parity is
1/(4000)^10 or 1E-36 (thats one in an unodecillion (I think) for right
thinking people, and one in a sextillion for Brits :-). This seems
like a very small chance, but seeming isn't believing.
Lets assume that the Earth is covered, on average, by 100 meters of a 1%
solution of amino acids. (I realize that creationists would allow me
to assume that it was covered to the height of Mount Arrarat, but I'm
being conservative.) This gives a total number of amino acid molecules
of (and you can work this out for yourself if you want) 1E43 amino acid
molcules, give or take a few orders of magnitude. Thus, there would be
ten million self-replicationg molecules at first, but once you have a
self replicating molecule, much of the primordial soup will become that
molecule.
Now, you've got a bunch of soup which is not primordial, but
contains chains of about ten amino acids. Eventually, a bunch of those
chains will come together in just the right way, and become a
self-replicating supermolecule. This is similar to an ordinary
self-replicating molecule, except that it puts together ordinary
self-replicating molecules to make copies of itself. Eventually DNA (or
the quintuply stellated octahelix :-) or some such thing gets invented,
and gives one particular type of molecule a huge advantage which allows
it to take over.
This process goes on and on, and eventually you have something
which you have to call life (If only because it slurphs up to you on
its fnurmlies and greckles you in no uncertain terms that its alive.)
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). The
fact that we walk on our feet instead of slurphing on our fnurmlies (or
doing something incomprehensible) is due to the same type of
coincidence.
David Norris mentions that:
Earlier in the chapter, it was noted that the time required for 1
million monkeys typing at 100 words/minute, 24 hours a day on
typewriters with 40 keys to type the first four words of a Shakepearian
play would be about 100 billion years.
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.
________
"Every day its the same thing--variety. I want something different."
David Palmerbill@utastro.UUCP (William H. Jefferys) (05/02/84)
I have posted a response to this article in net.origins; I
suggest that further discussion of this issue take place there.
--
Bill Jefferys 8-%
Astronomy Dept, University of Texas, Austin TX 78712 (USnail)
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