Expert: Dana Krempels, Ph.D. - 10/13/2009

Question
How could genetic code evolve as a results of random mutations (ie errors) and the other mechanism of the evolution-survival of the "fittest"? How did interaction between coding DNA and aminoacids evolve?

Answer
Dear Andy,

I must answer this question by saying:  No one truly understands the answer to this question yet.  We have come to understand how organic molecules could have been generated in the primordial oceans only recently, and you can read about this here:

http://www.chem.duke.edu/~jds/cruise_chem/Exobiology/miller.html

But the earliest evolution of the DNA molecule (actually, RNA is believed to have been the first genetic material, and the more stable DNA is believed to have been derived from RNA) is not well understood, and in the short time we have been studying the mechanisms of the origin of life, scientists have not yet been able to duplicate this chance event (which the earth had millions of years to "get").

Similarly, no one yet knows how the interaction between DNA and the genetic code for amino acids evolved.  This is one of the great mysteries of life's origin that we have yet to understand, and unfortunately we have no way to go back and watch how it happened.  

We *do* understand how genetic drift and natural selection work to drive evolution NOW. And we understand how DNA, RNA and amino acids interact to encode life NOW.  But the origin of the entire "raw material of evolution" has yet to be discovered.

This is where many people simply invoke a supernatural power, and I guess if you really need to do that, I'm not going to argue, since this question cannot yet be addressed by Science.  But scientists are working on it.  

Hope that helps.

Dana