The Redditors don’t even hesitate. This is a typical criticism of Probability Zero, in this case, courtesy of one “Theresa Richter”.
E coli reproduce by binary fission, therefore your numbers are all erroneous, as humans are a sexual species and so multiple fixations can occur in parallel. Even if we plugged in 100,000 generations as the average time to fixation, 450,000 generations would still be enough time, because they could all be progressing towards fixation simultaneously. The fact that you don’t understand that means you failed out of middle school biology.
This is a perfect example of Dunning-Kruger Syndrome in action. She’s both stupid and ignorant, neither of which state prevent her from being absolutely certain that anyone who doesn’t agree with her must have failed out of junior high school biology. Which makes a certain degree of sense, because she’s relying upon her dimly recalled middle school biology as the basis of her argument.
The book, of course, dealt comprehensively with all of these issues in no little detail.
First, E. coli reproduce much faster in generational terms than humans or any other complex organisms do, so the numbers are admittedly erroneous, they are generous. Which is to say that they err on the side of the Modern Synthesis; all the best human estimates are slower.
Second, multiple fixations do occur in parallel. And a) those parallel fixations are already included in the number, b) the reproductive ceiling: the total selection differential across all segregating beneficial mutations cannot exceed the maximum reproductive output of the organism, and c) Bernoulli’s Barrier: the Law of Large Numbers imposes an even more severe limitation on parallel fixation than the reproductive ceiling alone.
Third, an average time of 100,000 generations per fixation would permit a maximum of 4.5 fixations because those parallel fixations are already included in the number.
Fourth, there aren’t 450,000 generations. Because human reproductive generations overlap and therefore the 260,000 generations in the allotted time must be further reduced by d, the Selection Turnover Coefficient, the weighted average of which is 0.804 across the entirety of post-CHLCA history, to 209,040 generations.
Note to PZ readers: yes, the work continues. Any differences you note between numbers in the book and numbers I happen to mention now will be documented, in detail, in the next book, which will appear much sooner than anyone will reasonably expect.
Now, here’s the irony. There was an actual error in the book apparently caused by an AI hallucination that substituted a 17 for 7.65 for no discernible reason that anyone can ascertain. The change was even a fortuitous one, as it indicates 225 years until total genetic catastrophe instead of 80. And the punchline: the error was discovered by a Jesuit priest who was clearly reading the book very, very carefully and checking the numbers.