Tuesday, August 18, 2009

Eugene Koonin: It Is Certain

I wish I had a nickel for every statement of evolutionary certainty that later had to be dropped. Carl Zimmer's recent piece on how eukaryotes are supposed to have evolved quotes Eugene Koonin as stating that "it is certain" that a long time ago, in a warm pond far far away, two cells (an archaea and a bacteria) symbiotically merged to form the first eukaryote. The rest, as they say, was history, as from that humble eukaryote sprung everything from the trilobite to the tyrannosaurus.

So how exactly did this dynamic duo, an archaea and a bacteria, perform such a miracle? How did the massive changes, required to produce the incredible eukaryote cell, come about? It would be like merging two motorcycles to produce a jetliner. As Zimmer reports, Koonin and his co-worker William Martin have just the just-so story. Koonin and Martin suspect that:

early eukaryotes would have been particularly vulnerable to attacks from mobile elements. They propose that the nucleus—the structure that gives eukaryotes their name—evolved as a defense against this attack. After mobile elements are transcribed into single-stranded RNA, they are copied back into the genome. With the invention of a nucleus, RNA molecules were moved across a barrier out of the nucleus in order to be translated into proteins. That wall reduced the chances of mobile elements being reinserted back into the genome.

So there you have it--junk science at work. There was a need for that jetliner so, presto, it sprung forth. No question about it, evolution is smarter than evolutionists.