Re: Re[2]: probability and ap...

GRMorton@aol.com
Thu, 7 Sep 1995 07:31:09 -0400

jgibson writes:

"In your calculation of the number of amino acid strings of
length 110 in the phase space of strings of length 112,
you used the calculation:

**[110] + *[110]* + [110]** => 3 x 2^20 = 3145728

Why did you use 2^20 rather than 20^2 in this and the
succeeding calculations?

<<

Oh, boy, I hope I didn't mess this up. Each location has a choice of 20
amino acids which can be placed there. Thus,
to partially list them out, you have, (using letters as representations for
amino acids.

aa ba . ta
ab bb . tb
ac bc . tc
ad bd . td
... ... .
at bt . tt

This shoud be 20 x 20 for two locations. If you go to 3 locations, it is 20
x 20 x 20.

Jgibson wrote:
>>A comment on the probability of obtaining a given sequence
of amino acids. The significance of this question
for the question of the origin of life is different from
its significance for biological variation. In
biological variation, a system for making proteins from
amino acids is presupposed. In questions of the origin
of life, no such system would be available. In this
situation, the probability of obtaining ANY
meaningful protein seems to be to be effectively zero.
Proteins simply do not arise de novo in nature.

<<

I agree that proteins don't arise de nova. But the math of this problem is
applicable to the RNA world also.

glenn