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Old 26th April 2008, 11:08 PM   #130
Reality Check
Penultimate Amazing
 
Join Date: Mar 2008
Location: New Zealand
Posts: 26,437
Originally Posted by wogoga View Post
The hypothesis that the DNA contains the very specific information concerning protein folding and enzymatic behaviour leads to this problem:
It is extremely improbable that different reading frames of the same DNA can lead to viable protein parts, because a frame shift leads to a more or less random amino acid sequence.
In a similar way, it is highly improbable to find a reasonable text which can be transformed into another reasonable text by a character-transformation such as for instance: a -> b, b -> c, c -> d, z -> a.

In the following I assume that all 20 amino acids are equivalent, ignoring codon bias, stop-codon readthrough and similar. I assume also that a frame shift in a given sequence leads to a fully random sequence.


Let us call viable amino acids sequence a polypeptide which can be part of a protein with enzymatic activity. Assuming a chain of 100 members in the following, let us ask how many sequences are actually viable. Definitely, we can be sure that the answer must lie in between theses two extreme cases:
  1. Only one sequence is viable; the probability that a random sequence is viable is (1/20)^100 = 10^-130.
  2. All 20^100 = 10^130 sequences are viable; the probability that a random sequence is viable is 1.
In the first case we have an average viability-probability per amino acid of 1/20 = 5% and in the second case 1/1 = 100%.

Now let us assume that the viability-probability per amino acid is 25%. That means that at every position of the chain with 100 members, (because of mutual constraints only) 5 out of the 20 different amino acids can be used for a viable sequence to result. In this case, 5^100 = 10^70 viable sequences exist, and the probability that a random sequence is viable is (5/20)^100 = 10^-60.

The application of a frame shift to these 10^70 viable sequences leads to 10^70 random sequences (according to the simplifying hypotheses mentioned above). Because the probability of a random sequence being viable is 10^-60, we find around 10^10 viable sequences among these frameshifted sequences. Nevertheless, only one out of 10^60 viable sequences is able to produce another viable sequence by frameshift.

What happens however, if the viability-probability per amino acid is 20% instead of 25%, which means that at every position of the chain, 4 out of 20 amino acids are possible for a viable sequence to result. In this case, 4^100 = 10^60 viable sequences exist, and the probability that a random sequence is viable is (4/20)^100 = 10^-70.

So the application of a frame shift to the 10^60 viable sequences leads to 10^60 random sequences. Yet because the probability of a random sequence being viable is only 10^-70, it is highly improbable that one single of these frameshifted sequences is viable. Because actual viability-probability per amino acid seems to be lower than 20%, not even an almighty designer could create one DNA sequence, coding for two viable (100-amino-acid long) protein parts in two different reading frames, because such a sequence is excluded by probability theory.

I'm sure that every unprejudiced person being able to understand the above reasoning must admit: A biology, where the whole evolutionary progress is stored in DNA and to a lower extent in other material structures, is simply impossible from the logical point of view. Whether such a purely materialistic biology has the form of neo-Darwinism or the form of Intelligent Design does not matter.

Cheers, Wolfgang
I have to add my 2 cents worth and agree with the previous posters:
Wolfgang. Please please please learn some basic biology before you make yourself more ridiculous than you already seem.
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