“Intelligence,” OUT OF NOTHINGNESS!

[Coffee Jesus]

"If you equate the probability of the birth of a bacteria cell to chance assembly of its atoms, eternity will not suffice to produce one...”

Humans and all mammals have some 50,000 genes. That implies, as an order of magnitude estimate, some 50,000 to 100,000 proteins active in mammalian bodies.

Humans have about 20,000 genes, but about 100,000 proteins. This is because of alternative RNA splicing. Basically, the RNA transcript of the gene has exons and introns. The exons are joined together as the introns are removed, and the final product is translated into a polypeptide (the composing unit of a protein). The term "alternative RNA splicing" denotes instances of mutually exclusive exons, allowing the RNA to be "spliced" in multiple ways to produce slightly different proteins. This is probably the explanation for why we have so many more proteins than genes.

This means that the number of possible combinations of the amino acids in our model protein of 200 amino acids is 20 to the power of 200 (i.e. 20 multiplied by itself 200 times), or in the more usual 10-based system of numbers, approximately 10 to the power of 260 (i.e. the number one, followed by 260 zeros!). Nature has the option of choosing among the 10 to power of 260 possible proteins, the 3 million proteins of which all viable life is composed. In other words, for each one correct choice, there are 10 to power of 254 wrong choices! Randomness cannot have been the driving force behind the success of life. Our understanding of statistics and molecular biology clearly supports the notion that there must have been a direction and a “Director” behind the success of life.

The irony is that artificial selection is actually a better designer than we are. We have no clue how to design a brand new protein for a particular function, yet we can produce one through "directed evolution".

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2997618/

Engineering enzymatic activity is particularly difficult, because very small changes in structure or chemical properties can have very significant effects on catalysis. Thus predicting the amino acid sequence, or changes to an amino acid sequence, that would generate a specific behavior remains a challenge, particularly for applications requiring high performance (such as an industrial enzyme or a therapeutic protein). Unfortunately, where function is concerned, details matter, and we just don't understand the details.

Evolution, however, had no difficulty generating these impressive molecules. Despite their complexity and finely-tuned nature, proteins are remarkably evolvable: they can adapt under the pressure of selection, changing behavior, function and even fold. Protein engineers have learned to exploit this evolvability using ‘directed evolution’ — the application of iterative rounds of mutation and artificial selection or screening to generate new proteins. Hundreds of directed evolution experiments have demonstrated the ease with which proteins adapt to new challenges.