Evidence for Evolutio8

Evidence for Evolutio8 - Evidence for Evolution Genetic...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Evidence for Evolution Genetic drift and Mullers ratchet Here's a switch, I'll try posting something productive instead of flaming people. I'll discuss here a paper in a recent issue of Nature. The author, Lin Chao, examined the RNA virus phi 6 to see if Muller ratchet was operating. I'll post this in two parts. In part one I'll explain what Mullers ratchet and genetic drift is. In part two I'll summarize the paper and explain it's significance. H.J. Muller proposed, in 1964, one reason why sex may be beneficial to organisms. In a strictly asexual lineage, recombination is not possible (in sexual lineages it, of course, is). Thus, any mutation that occurs in an asexual lineage can only be corrected in one of two manners. The back mutation can occur or a compensating mutation can occur. Since mutations occur at random, the probability that the next mutation occuring in the lineage is the back mutation is low. Thus, each new mutation the lineage absorbs is likely to be a unique mutation. And, since mutations are most often deleterious; an asexual lineage is expected to decrease continually in fitness. Compensating mutations are also highly unlikely. This continual decrease in fitness, driven by
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/14/2011 for the course BIO BSC1010 taught by Professor Gwenhauner during the Fall '10 term at Broward College.

Page1 / 2

Evidence for Evolutio8 - Evidence for Evolution Genetic...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online