Tuesday, March 16, 2010

Genetic equidistance as shown by a list of most conserved proteins

I am reading a popular textbook on bioinformatics, “Bioinformatics and Functional Genomics” 2009 by Jonathan Pevsner, in preparation for a course I am going to teach. On the topic of evolution and phylogeny, the book shows a table of a list of 20 most conserved proteins found in yeasts, worms, and humans. The table was taken from an old paper by the Bork group (1). The original table was meant by those authors to demonstrate protein conservation. They have no intention to show the genetic equidistance result and made no comment of it. But note how uniformly striking that yeast is approximately equidistant to worms and humans in all 20 proteins listed. Those proteins happen to be among the most conserved, although the equidistance phenomenon is not related to how conserved a protein is. I cite this table as a piece of independent evidence to support my claim that the genetic equidistance result is a nearly universal feature of all proteins (2). People simply cannot avoid encountering it.

1. Copley RR, Schultz J, Ponting CP, Bork P. (1999) Protein families in multicellular organisms”, Current Opinion in Structural Biology, 9:408-415.

2. Huang S. (2008) The genetic equidistance result of molecular evolution is independent of mutation rates. J Comp Sci Syst Biol; 1:092-102.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3184610/