Figure 1.

Study Overview

Schematic of the divergence, crossing, and selection phases of the experiment. Two diverged S. cerevisiae lineages (WA and NA) were crossed for twelve rounds, generating a large ancestral population of unique haplotypes. These diploid cells were asexually evolved for 32 days in stress and control environments, and their adaptation was studied by whole-population and isolate sequencing and phenotyping. Populations evolved resistant macroscopic subclones driven by individual cells with beneficial genetic backgrounds (i.e., parental allele configurations) and by beneficial de novo mutations that provided a resistance phenotype.