bohm
It is estimated that it would take 10X10^21 mutations to get five condons to mutate in the right order.
1) Just for my own sake, how do you compute this number?
The calculations for chimp to human I do not have at this time.
Below is the probability of producing a 150 amino acid molecule. That is 50 codons. The numbers below surpass the probability of 10^21
To construct even one short protein molecule of 150 amino acids by chance within the prebiotic soup there are several combinatorial problems – probabilistic hurdles- to overcome. First, all amino acids must form a peptide bond when joining with other amino acids in the protein chain. If the amino acids do not link up with one another via a peptide bond, the resulting molecule will not fold into a protein. In nature many other types of chemical bonds are possible between amino acids. In fact, when amino acid mixtures are allowed to react in a test tube, they form peptide and none peptide bonds with roughly equal probability. Thus, with each amino acid addition, the probability of it forming a peptide bond is roughly ½. Once four amino acids have become linked, the likelihood that they are joined exclusively by peptide bonds is roughly [1/2]^4. The probability of building a chain of 150 amino acids in which all linkages are peptide linkages is {1/2}^149, or 1 chance in 10^45.
Second in nature every amino acid found in proteins [ with one exception] has a distinct mirror image of itself, there is one left handed version, or L form, and one right handed version, or D form. These mirror image forms are called optical isomers. Functioning proteins tolerate only left handed amino acids, yet in abiotic amino acid production the right handed and left handed isomers are produced with roughly equal frequency. Taking this into account further compounds the improbability of attaining a biologically functioning protein. The probability of attaining, at random only L amino acids in a hypothetical peptide chain 150 amino acids long is [1/2]^150 or roughly 1 chance in 10^45. Starting from mixtures of D and L form the probability of building a 150 amino acid chain at random in which all bonds are peptide bonds and all amino acids are L form is, therefore, roughly 1 chance in 10^90.
Amino acids link together when the amino group of one amino acid bonds to the carboxyl group of another. Notice that water is the byproduct of the reaction. [Condensation reaction].
Functional proteins have a third independent requirement, the most important of all, their amino acids, like letters in a meaningful sentence, must link up in functionally specified sequential arrangements. In some cases, changing even one amino acid at a given site results in the loss of protein function. Moreover, because a there are 20 biologically occurring amino acids, the probability of getting a specific amino acid at a given site is small 1/20 [actually the probability is even lower because in nature, there are also may none protein forming amino acids.] On the assumption that each site is a protein chain requires a particular amino acid, the probability of attaining a particular protein 150 amino acids long would be [1/20]^150 or roughly 1 chance 10^195. 1chance in 10^195.
2) How does this number disprove evolution? (what is the full argument as to why this computation shows Humans and Chimps do not have a shared ancestor)
Following the computations. If the difference between a chimp and a human is 15 million codons, and it takes 10^21 to mutate 5 codons, what is the total probability when we include the other 14,999,995 codons. It is an impossibility. When applying comparative anatomy we do see similarities, but on the genetic level there is a huge gap, that makes evolution an impossibility.