A correspondent was moved by my previous post to send me a fragment of a book that he had read, Signature in the Cell by Stephen C. Meyer. In this fragment it is demonstrated that there simply has not been time for a protein, made up of 150 amino acids, to have evolved by chance. That is time since the 'big bang' of 13.7 billion years ago. It goes something like this:
There are 20 different amino acids.
To make a combination of 2 = 20^2 = 400 possibilities.
To make a combination of 3 = 20^3 = 8000 possibilities.
To make a combination of 4 = 20^4 = 160000 possibilities and so on...
Most proteins are made up of sequences of hundreds of amino acids.
The minimum number of amino acids for a functional protein is 150.
So that means 20^150 = 10^195 combinations.
We are then asked to consider the following three points:
1. Amino acids make both peptide and non-peptide chemical bonds in the ratio of 50:50. Peptide bonds are needed for the chain to fold into a functional protein. Only half of the bonds have value. So (1/2)^149 = 10^45.
2. There are both left hand and right hand amino acids. Proteins tolerate only left hand acids. The probability of this is (1/2)^150 = 10^45.
3. Amino acids must link up in the correct sequence in the same way that letters must link up correctly to spell out meaningful words and sentences. Given 20 acids this probability is 1 in 20^150 = 10^195.
At this point, it is noted that proteins do function with some variance in sequence so a calculated value of 10^74 is used. This is considered to be generous.
So the probability of finding one functional protein in some primordial soup is given as 10^45 x 10^45 x 10^74 = 10^164. Note that the total number of atoms in the entire universe is given as 10^65. If one solitary atom in the entire universe bore your name, it would be significantly easier to find it - blindfolded!
A minimally complex cell needs about 250 such proteins of 150 amino acids in length.
We are now asked to consider a time factor. There is an upper limit to the number of physical transitions that can take place in a given time. A Planck second is the time it takes for light to traverse the smallest significant unit of distance, and there are 10^43 of these in a second. There have been 10^17 seconds since the big bang. There are, apparently, 10^80 elementary particles in the observable universe. To have a good chance, better than 50:50, of producing a single functional protein there needs to be time of more than half of the 10^164 possibilities to have been generated. The maximum number of opportunities is 10^43 x 10^17 x 10^80 = 10^140. (1/2)^164 exceeds this number by 24 orders of magnitude, or a trillion trillion years more than have been available.
That is the fragment in very condensed form. I hope I have it right and correct. So if an evolutionist fobs you off with a 'Ah, but given enough time...'
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