The best explanation may be an apocryphal quote attributed to Benjamin Franklin: “Beer is proof that God loves us and wants us to be happy”. S. cerevisiae is the organism of choice for these studies because the genomic and related resources that are available are, quite simply, better than for any other organism on the planet. There are eukaryotes with smaller genomes, to be sure, but the extent of knowledge about these species pales by comparison to S. cerevisiae. This offers the opportunity to bring to bear the extensive universe of yeast systems biology information to the design of chromosomes for the organism. Undoubtedly the synthetic yeast will differ from the native organism, and the multitude of genetic assays available for the organism can be used to understand any phenotypic differences that might be observed.

Note: Benjamin Franklin’s written correspondence shows a similar quote about wine (perhaps motivation for his service as ambassador to France) but no direct evidence for the quote about beer. The image is a painting by Joseph-Siffred Duplessis from 1778 that is in the public domain.