I love giving long 'old-School' titles
Anyhow, as I hope everyone that will join this discussion knows, statistics is a very interesting subject. One of the properties of a random sequence is that, given enough repetitions, it will always tend to go towards a certain %. I may not be clear, so here is an example:
_ If I flip a coin for a very long time, the amount of heads and tails I should register should be close to 50% each.
Now, if we start with a simplistic model of mutations where they are a totally random and apply this fact, then given enough time and mutations, the % of each nucleotides in the genome should tend towards 25%. Natural selection, of course, gives no advantage to either of the nucleotides and therefore should not influence this ratio.
I have searched for data on this ratio in different animals and I have come close to nothing in terms of actual numbers. From my biology book:
- In humans: A=30,3%. T=30,3% G=19,5% C=19,9%
- In E.Coli: A = 26%. (And so probably T=26%, but it is not explicitly said).
I intend this discussion to be more of a knowledge learning for me, and so it is NOT a debate. Please try to keep this in mind everyone. I'll start off with a couple questions:
1- Can mutations be approximated as totally random, and if not, can/does this change the expected proportions of the nucleotides in the Genome ?
2- Does anyone have more information on such proportions from other species ? The more information we have, the more interesting this will be.
3- Has such an analyses of proportions been done and published in the past ?
4- In the hypothetical situations that it turns out that there is a common trend in the different species to favor the A and T base, what could be the possible explanations, from an evolutionnary perspective, for this ?
I consider that if there would be a natural mechanism that favors significantly some nucleotides over others, than this would be a powerful mechanism analog to natural selection in a certain way, and that it's discovery would merit the Nobel Prize ... haha
Hopefully, with all the brilliant minds on this forum who have worked in biology and genetics all their life, I will be able to obtain moe information on this idea I had while eating my cereals 2 weeks ago.
PS I keep the copright on this idea and anything that stems from it lol