So how does that work for DNA? How do you determine if a sequence of nucleotides or amino acids fits this pattern? Here is the amino acid sequence for human cytochrome c:
If that was a string of Scrabble tiles, would you say that it was designed?
If you had given me this string, I would ask three questions:
1) Is the string the product of some algorithm or law-like process?
2) Is the string highly improbable?
3) Does the string match some external pattern or category of patterns?
1) Since Scrabble letters are free to be arranged in any order, no law-like process was operational. I could also test to see if the sequence demonstrated correlations which would point to some law-like process, or does the sequence appear close to random.
2) The number of letters is large enough to preclude the possibility of pure chance. In contrast, if the string had been CAT, the pattern matches a word, but such a short sequence could happen by chance.
3) Finally, I would attempt to match the pattern to some known pattern. I might start with attempting to match the sequence to a sentence in some language. Ideally, I would eventually recognize that the letters matched amino acids. I would then run a BLAST search to see if the pattern matched closely enough to the sequence of some known protein to rule out chance. I would then find a match and know that the sequence was designed.
In the case of the origin of life, a minimally functional cell requires a precise set of reactions to take place in an enclosed space. However, reactions in cells rarely proceed quickly enough to maintain the metabolism. Even more problematic many of the reactions are energetically unfavorable - they move to higher free energy. Therefore, they need enzymes which will link reactions moving downhill (ATP --> ADP + P) with the desired cellular reaction. Such a linking requires an enzyme which targets all of the right molecules and then drives the two reactions in the right order. The minimal cell requires a whole suite of such enzymes, and each enzyme requires that amino acids (or nucleotides) link together in the right order. The probability of such fortuitous arrangements of letters in numerous chains is fantastically improbable. To give an example, the likelihood of random amino acids forming a functional cytochrome c was calculated by Robert Sauer from MIT to be 1 in 10^65 (Reidhaar-Olson, J. F., & Sauer, R. T. (1990) "Functionally Acceptable Substitutions in Two -Helical Regions of Repressor", Proteins: Structure, Function, and Genetics 7, 306-316.).
Finding all of those enzymes in the right vicinity to drive a functional cell is as striking as finding an occlusions pattern with phone numbers. In the occlusion example, the number sequences derived from the crystal matched phone numbers that happened to be the numbers of researchers in the lab. In the case of the enzymes, the sequences of amino acids (or nucleotides) are the right sequences to correspond to enzymes which match the required reactions for the cell. The sequences of amino acids represent information.
The analogy is as follows:
AA sequences --> sequences of numbers (information)
Function enzymes --> operational phone numbers
Needed reactions for cell --> phone numbers of scientists who worked in lab
The challenge is that information is typically contained in a medium which is disconnected from the functional goal of the information. The blueprint for a house is contained on paper, not the materials which make up the house. In contrast, the information representing the right order of amino acids is contained in the sequence of amino acids which is both the medium and the goal of the information. The goal is for the sequence to fold into the right shape to drive the right reactions. This result would be like the ink making up the blueprint for a house causing the paper containing the ink to fold into the form of the desired house.
(To be continued)