🚀 go-pugleaf

In article <41323@imag.imag.fr> bessiere@imag.fr (Pierre Bessiere) writes:
>The order of magnitude of the number of nucleotides [in the human
>genome] is, therfore:
>3 x 3 10^2 x 10^7 = 9 x 10^9
[...]
>The order of magnitude of the number of theoreticaly different human
>being is : 4 ^ (9 x 10^9) let say to simplify 2 ^ (10 ^ 10).

     There is something badly wrong with this analysis.  We can't
randomly select all the bases and wind up with something living, never
mind human.  I have heard that the variability among human DNA is less
than 1% (much less?).  At most then, the number of possible genetically
different humans is 2^(10^8).  However, even this number must be too
large.  In most cases, it might be perfectly all right to change a single
base here or there, but multiple changes in the same gene might lead to
nonviable organisms.  This is becoming interesting.  Does anyone have
any idea of how many substitutional degrees of freedom human DNA has in
its current state?  I realize that this is a hopeless question to answer,
especially since it only captures part of the potential variability;
insertions and deletions are also possible and these would tend to
inflate the number of possible genetically different humans.

				Marc R. Roussel
                                mroussel@alchemy.chem.utoronto.ca