Joined: Jan. 2014
I am trying to write up a shorter and clearer (so creationists can read it) version of Lenny Flank's argument about mutation rates as implied by the number of alleles in the MHC complex. I also want this rewrite because (among other things) the creationist response focuses on his use "beneficial" mutations. (See: http://creation.com/bible-t....versity )
In my first draft I began:
MHC regions are usually less than 2000 bp long in a genome that is 3,000,000,000 bp long.
Observationally we know there are a 100 mutations per generation over the entire genome.
Therefore in a region that is:
- 300,000,000 bp long we would expect one mutation per generation.
- 3,000,000 bp long we would expect one mutation ever 100 generations.
- 3,000 bp long we would expect one mutation ever 100,000 generations.
Since we sometimes see more than 1000 mutations (alleles) in the 2,000 bp long MHC immune complexes this suggests these areas have been mutating for 100,000,000 generations.
Here I said to myself 100,000,000 generations seems like way too many, unless (for example the mouse MHC complex looks fairly similar - does it?). If it does not, what is a more reasonable estimate of the number of generations to achieve the diversity we see in the human MHC complexes?
Also is the observed generation to generation rate of mutations in the MHC complexes much different from that observed in the rest of the human genome?