Question

In the class we have discussed that bacteria can evolve much faster than animals and plants because they grow much faster and have larger population sizes. To put this in a context, do you think it is possible statistically that every single base pair in the E. coli genome has experienced a mutation in a 5 ml E. coli overnight culture? We know that there are ~1010 cells in the 5 ml overnight culture and the mutation rate of E. coli is 10-9per base pair per DNA replication.

Answer 1

E coli has 4 639 221 base pairs which is nearly 5* 10⁶ pairs per genome and with a mutation rate of 10^-9  it gives nearly a 10^-3 mutations per genome replication. since an overnight culture has 1010 cells, during the final doubling there will be 10¹⁰ genomic replications and therefore number of novel mutations will be nearly 10⁷ (10¹⁰ * 10^-3) since the number of mutations that is possible to occur is close enough to the number of base pairs of the whole geome it is statistically possible that every bp is experiencing a mutation