Figure 2. Laboratory evolution selects for both loss-of-function and alteration-of-function mutations.

The number and type of mutations observed in common targets of selection in experimental evolution (left y-axis), and the posterior probability that evolution selects for loss or alteration of function (right y-axis). Black dots are genes absent from the deletion collection (Giaever et al. 2002). These data were aggregated from seven yeast evolution experiments. We used a Bayesian approach to determine the posterior probabilities that selection acts on loss or alteration of function. Note that for genes where selection is inferred to be selecting for alteration-of-function, nonsense and frameshift mutations are occasionally observed. Prior probabilities for loss or alteration of function and conditional probabilities for mutational spectra were determined from experimental data as described in Vignogna et al. 2022.