Mutual Divorce - tree of life (Jan/18/2006 )

man it pisses me off when that happens I had like the longest reply!!! GRRRRR

ok here goes again...

What about the variation present in the original population, where is that taken into account? In a simplistic view of evolution some part of the population is segregated from another (perhaps by a large canyon formed by an earthquake for example) As the two populations cannot mix there begins to arise different muations in each eventually they are different enough taht they cannot breed then with more time they look different etc.. How is this taking into account the normal variation present in a large population versus a small one etc...

This powerpoint looks cool... didn't take much time with it (you have realized by now how little I really know about this right? )

http://www.cs.utexas.edu/users/tandy/neyman.ppt

In the first part, I understand better the question now, I agree that reproductive genes are probably changed to prevent the reproduction between two species... you could also just make them not be attractive to each other but this may not fit the definition of "mutual divorce"

Your logic seems good in the second part, the real question is how much resolution you lose b/c the sequences have a high mutation rate I mean if you only drop fibrinogen then you haven't lost much resolution etc...

Try searching evolutionary distance DNA in google and pubmed, some interesting stuff... in pubmed some of the papers seem like they are differentiating pretty closely related groups...

I really HATE math and I basically suck at it, but when I put your equation into google alot of physics papers with atoms etc in the title came up... Not the same exact eq. as far as I could tell, but is likely the same kind of math is used to solve both of these problems... cant find anything on that constant, but it must have been made by comparing two organisms whose evolutionary distance were already known by carbon dating or other phylogenetic methods (used to use phenotype etc...)

Ok now to my previous postulate, not as good as it sounds... even if you pick a single gene the need for that gene to be conserved may change over time.. for example, Gene A is highly conserved but in one species they evolve gene B which has redundant role with A but is much less efficient... this means that gene A still looks very conserved, but in this species and all that evolve from it and have gene B the need for conserving gene A is somewhat less... if subsequent species have mutations that improve the efficiency of gene B then you could eventually drop the requirement for gene A altogether and replace with B... this could also happen in reverse, somewhere in the middle an organism makes gene B less efficient again thus returning the requirement for gene A back to original rate... So even with the same highly conserved gene, over time the requirement for conservation may change alot so sounded good on the surface but not a realistic solution I think...

whew I think I made it that time... probably helped alot I was rambling before hopefully this time the answer is clearer and more concise-- still sucks to have had to retype it

let me know what you think....

Thanks for being patient...

The power point was really good. But it seemed that the reproductive separation time is not specefically calculated. It is assumed that the time given by highly conserved genes is approx. same as the 'mutual divorce' time as there are less chances of changes in highly conserved genes to change when inbreeding is on.


The ,dynamicness of conservedness of a gene is very important! I didn't notice it till you posted it for me. I'm explaining what i undersood and my thoughts-
Allele frequencies of the genes are also important. For some time inerval if the allele frequency of gene A is almost 1 { phase A1}, and then anpther allele ,B evolved , due to some environmental changes B got in the position of major allele {phase B1} ; allele freq. of A became very less.
After that again A became the major allele in similar way {phase A2, today}. So, if some species has diverged from this line when B was the major allele. It might still have the B allele as major allele depending upon environment, specific chara. of that speciesetc. But if we have a fossils from A2 /today and A1, but not from B1. we would not be able to get correct result , because we may not notice the B1 phase!!! So, the actual mutual divorce time may not be obtained correctly and with acceptable error level.

I'm trying to put that 1/2 as a power of log
& see if any concept emerges out the eqn. or do some other changes to get any 'readable' form of the eqn.

Correction in the previous post-
3. the eqn is

2Kt= -ln(1-d/n)...

K=-(1/2).(1/t).ln(1-d/n)

n=no of residues
d=no. of sites having different residues
t=time interval
K= the rate of evolutionary amino acid substitution per site per year.
[ K = -(1/2).(1/t).ln[(n-d)/n]

Shrei