We don't know this, because we haven't modeled more than a measly million creatures. You won't let me extrapolate using that fitted curve, but if I did extrapolate to a lousy billion creatures, it would require 103 generations; to a trillion creatures, 21 generations. Of course, there is some asymptote it's approaching, although I haven't the slightest idea what that is.
No?
1 generation, obviously.
It is sometimes said that an infinite number of monkeys with typewriters would eventually produce
Hamlet. This is an understatement. Actually, if you had an infinite number of monkeys, one of them would type
Hamlet straight off.
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The mistake Kleinman has made, or one of them, is to take a realistic value for
p (the probability of a point mutation for a given base) but not for
n (the population). This gives a totally unrealistic value for the probability that a given substition will occur
in the gene pool per generation, which is given by:
q = 1 - (1 -
p/3)
n
If, for example, we take a realistic value for
p of 10
-8, then for a measly million organisms,
q is 0.3%. For a lousy billion, it's 96.4%.
If we use a more realistic order of magnitude for the bacteria, say something like the 10
14 present in a single human gut, then my calculator isn't accurate enough to tell us the difference between
q and 1.
Schneider is forced by practical constraints to take
n to be small, and has compensated for this by using an
unrealistic value for
p to give himself a
realistic value for
q. This is eminently sensible, since it is the amount of variation within the gene pool, rather than the variation between individuals per generation, that determines the rate of evolution.
Kleinman, on the other hand, has chosen his numbers so that the value for
q is wildly unrealistic; this is why his estimate of the time the process would take is also wildly unrealistic.