Clusters of “snowflake” yeast that evolved a multicellular life history.

<p>Confocal micrographs showing many clusters (left) and one at higher magnification (right). Colors show depth in z-axis. Unpublished images by Shane Jacobeen, Will Ratcliff, and Peter Yunker, Georgia Institute of Technology.</p

Incubator used in early experiment on adaptation by natural selection.

<p>Image from Dallinger (1887), now in the public domain (<a href="http://commons.wikimedia.org/w/index.php?curid=10531922" target="_blank">http://commons.wikimedia.org/w/index.php?curid=10531922</a>).</p

Experimental populations of <i>E</i>. <i>coli</i>, centered on the population that evolved the ability to use citrate in the LTEE.

<p>Photo by Brian Baer and Neerja Hajela, Michigan State University (<a href="http://commons.wikimedia.org/w/index.php?curid=4277502" target="_blank">http://commons.wikimedia.org/w/index.php?curid=4277502</a>).</p

Black Queen Monod model and fit to linear frequency dependence

Monod model of a black queen interaction, including dynamics of daily resource use, toxin reduction, and growth. Fits post-growth cycle relative frequencies to a linear parameterization of frequency dependent fitness

Cross-feeding Monod model and fit to linear frequency dependence

Monod model of a cross-feeding interaction, including dynamics of daily resource use and growth. Fits post-growth cycle relative frequencies to a linear parameterization of frequency dependent fitness

nuoM competition data

Colony count data from 6-day competitions between admixtures of nuoM+ and nuoM- clones

Fit competition data to linear frequency dependence

Mathematica notebook that fits competition data to a linear paramaterization of frequency-dependent fitness

Alleles derived from the K-12 donors tended to increase in frequency during the STLE continuation experiment.

<p>Initial and final K-12 allele frequencies are plotted on the x- and y-axis, respectively. Alleles that increased in frequency lie above the dashed diagonal line, and those that decreased lie below the diagonal. Alleles are colored based on their genomic position, so clusters with the same color probably belong to the same haplotype.</p

Mutations at 100% frequency in both the initial (1000 generation) and final (1200 generation) samples of the STLE continuation experiment and in both recombinant clones, which we infer to have been present in the last common ancestor (LCA) of each population.

<p>See legend to <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007199#pgen.1007199.g001" target="_blank">Fig 1</a> for description of symbols and labels.</p

Thirty-two genes under positive selection in the LTEE that harbored mutations in at least one of the recipient clones used to start the STLE.

<p>Thirty-two genes under positive selection in the LTEE that harbored mutations in at least one of the recipient clones used to start the STLE.</p