Mutations in yeast are deleterious on average regardless of the degree of adaptation to the testing environment

The role of spontaneous mutations in evolution depends on the distribution of their effects on fitness. Despite a general consensus that new mutations are deleterious on average, a handful of mutation accumulation experiments in diverse organisms instead suggest that of beneficial and deleterious mutations can have comparable fitness impacts, i.e., the product of their respective rates and effects can be roughly equal. We currently lack a general framework for predicting when such a pattern will occur. One idea is that beneficial mutations will be more evident in genotypes that are not well adapted to the testing environment. We tested this prediction experimentally in the laboratory yeast Saccharomyces cerevisiae by allowing nine replicate populations to adapt to novel environments with complex sets of stressors. After >1000 asexual generations interspersed with 41 rounds of sexual reproduction, we assessed the mean effect of induced mutations on yeast growth in both the environment..., , , # Data from: Mutations in yeast are deleterious on average regardless of the degree of adaptation to the testing environment

Bao et al yeast adaptation data

\[[Access this dataset on Dryad](https://doi.org/10.5061/dryad.pzgmsbcsn)]

In this dataset we have the raw reads from our growth rate assays. These assays were performed by placing 96-well plates into the Biotek assay reader which read OD over a period of time and at regular intervals. OD is used as a proxy for cell concentration and thus growth.

Description of the data and file structure:

All files provided are raw read data from the machine. Each column represents a well and the rows are the ODs over time. Each Regular Fitness Assay file is named with the date that a given assay was performed. Crossing Assays and Mutant fitness assays were the assays done to determine local adaptation and the fitness of mutagenized lines respectively. Each well's associated identity is marked in a *ref.csv file which has the well number in t...