Figure 2.

Experimental reproduction of selective sweeps, which were identified by a statistically significant change in allele frequency. (a and b) The replication of a significant increase in allele frequency, which reaches a high frequency. (c and d) The replication of a significant increase in allele frequency, which does not reach a high frequency. For each replication experiment, five replicate cultures were inoculated from a frozen stock (representing generation 378 in the original culture for the high frequency event, 108 for the low frequency event respectively). Allele frequency distributions are shown after 18 generations (a and c) and 90 generations (b and d) of independent propagation of the replicate cultures. Replicas were analyzed and tested for significant allele frequency shifts. In all replicate cultures, significant change in allele frequency was observed for the allele carrying 29 repeats (a and b) and for the 11-repeat allele (c and d). Arrows indicate the alleles, that significantly increase in frequency.