http://theosophical.wordpress.com/2...the-chance-hypothesis-for-the-origin-of-life/
The problem facing protein formation is similar to the problem of having to spell “I am going to Disney Land in California next Saturday with some friends and family who will be coming to stay with me for a couple of weeks from the venerable city of Venice, Italy” by randomly pulling letters out of a large pot one at a time. Inside the pot, however, is an equal number of English letters and Chinese characters. If I pull out an English letter that is not appropriate for the sequence, whatever portion of the sentence I was able to form purely by chance has to be discarded. Likewise, if I pull out a Chinese character from the pot, whatever portion of the sentence I was able to form purely by chance has to be discarded. The chances of being able to pull out the exact English letters in the exact sequence without ever pulling out a Chinese character is nearly impossible. And yet that is what would be required for even the simplest life form to begin.
What, then, is the likelihood that 150 L-handed amino acids would bond together without a single R-handed amino acid interfering, when there are an equal number of L-handed and R-handed varieties available? It is equal to the odds of flipping a coin and it coming up heads 150 times in a row: 1 in 1045. Add to this the odds of sequencing the 150 L-handed amino acids into a biologically meaningful/functional order (1 in 1074), as well as the odds of forming only peptide bonds between amino acids (1 in 1045), and we discover that the odds of forming a single, small protein are reduced to 1 in 10164 (a 1 followed by 164 zeros).[3] That’s 1 chance in 100 trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion. To put this in perspective, there are only 1080 number of protons in the entire observable universe! That means the chances of finding a specified particle in the observable universe are a trillion, trillion, trillion, trillion, trillion, trillion, trillion times greater than the chances of producing a functional protein consisting of only 150 amino acids. And these are the odds of forming just one protein. Since the simplest living cell requires at least 250 different proteins, the chances of forming the necessary proteins by chance alone is 1:1041,000!
But wait, you say, given enough time, couldn’t the odds be met? No. Given a liberal estimate, there have only been 10139 events in the entire universe since the Big Bang.[4] So even if every event in the history of the universe was devoted to building a single functional protein, the number of sequences produced thus far would be less than 1 out of a trillion trillion of the total number of events needed to give it even a 50% chance of success! And that’s just one protein! The other 249 would still need to be accounted for. Anyone who believes chance can succeed with these odds is being irrational.
Random chance cannot explain the origin of life, but what about necessity? Can natural law explain it? We’ll take up this possibility next time.
[1]Using knock-out experiments, the scientists who mapped the genome of M. genitalium concluded that 381 of the 482 genes/proteins are essential to its survival. Of extant cells, then, the minimal complexity for life is 382 genes/proteins.
In even the simplest of cells approximately 20 proteins are needed to transcribe DNA, more than 100 proteins are needed to translate RNA into proteins, and more than 30 are needed for replicating DNA during mitosis.
[2]The chances of forming a protein by chance are roughly equivalent to the chances of forming the gene that codes for the protein by chance (the information content is equal as well), but most OOL researchers choose to calculate the odds of forming proteins because it is simpler.
[3]This figure does not take into account additional factors such as the odds of all 20 amino acids being produced in enough quantities and being in close enough proximity to form a protein.
One might wonder why the odds of forming a functional sequence of 150 amino acids is not 1:10195 since that is the sum of 20 multiplied by itself 150 times. While that number does represent the odds of obtaining a specific amino acid sequence, we are only interested in the odds of obtaining a functional protein (and there are a number of sequences that will lead to a functional protein). The odds of obtaining a sequence of 150 amino acids that can perform a biological function, while astronomical, are considerably better than the odds of obtaining a specific amino acid sequence.