What happens in a yeast population? Greg Lang, associate professor of biological sciences at Lehigh University detailed his findings in his “Genome evolution in laboratory populations of yeast” talk at John Hopkins University‘s Department of Biology.

In the first project Lang described, he subjected haploid, asexually reproducing yeast to normal growth conditions — 30-degrees-Celsius temperatures and glucose-rich media — and let evolution play out for 1,000 generations. Three populations were isolated: one “ancestral” early clone from generation zero, one “intermediate” clone from the middle of the experiment and one “late” clone from the thousandth generation. To determine the relative fitness of these clones, Lang co-cultured the different yeast populations and measured their resulting growth rates. In nearly every population, the late clones exhibited higher fitness than the intermediate and early clones, indicating adaptive evolution. However, there was one outlier that did not exhibit this expected phenomenon.