Joined: Feb. 2006
|Quote (Henry J @ Oct. 04 2007,14:01)|
|Beyond A 'Speed Limit' On Mutations, Species Risk Extinction|
|Cambridge, Mass. - October 1, 2007 - Harvard University scientists have identified a virtual "speed limit" on the rate of molecular evolution in organisms, and the magic number appears to be 6 mutations per genome per generation -- a level beyond which species run the strong risk of extinction as their genomes lose stability.|
iirc, the average mutation rate for the coding section in humans is what, 1 or 2 per generation?
Two qualifications on this paper:
1) It's actually 6 mutations per essential part of the genome per generation. As best I can tell, the "essential part" in their model corresponds to the coding sequences for proteins that are essential to survival.
2) Their model assumes organisms reproduce independently. In other words, the calculated speed limit is only applicable to asexually reproducing organisms. Indeed, the authors compare their models only to empirical data from viruses and prokaryotes.