As reported in Nature and at MSNBC, Steven Oliver of the University of Manchester in England and his collegues have proven that evolution is a fact. He started not with two species of apes like humans and chimps, but instead with two species of yeast called Saccharomyces cerevisiae and Saccharomyces mikatae. Genetically S. cerevisiae is believed to have evolved from S. mikatae, and the two are considered different species because they cannot interbreed together to create fertile offspring. Looking at the chromosomes of these species of yeast, the only difference between them is that the tips of two of their chromosomes are swapped. Dr. Oliver took a colony of S. cerevisiae and used genetic engineering to swap their chromosome tips of interest and thereby create a new yeast colony. This new yeast colony was able to crossbreed with S. mikatae and produce offspring where one-out-of-three were fertile. Thus, the newly created colony of modified S. cerevisiae now meets the scientific definition of being members of the S. mikatae yeast species; they de-evolved into a more primitive species. “This is a very different approach to understanding evolution,” says evolutionary geneticist Cliff Zeyl of Wake Forest University in Winston-Salem, North Carolina.

Even the research team said it would be a mistake to claim that chromosome-swapping was the only factor behind the divergence of species. “Genetic divergence needs some sort of isolation (either geographical, ecological or behavioral) between incipient species to develop, and chromosomal rearrangements might have provided at least partial isolation,” the researchers said.

Recreating old species by shuffling chromosomes is of more than academic interest. For example, it provides one explanation for the mysterious and sudden appearence of corn in human history. Controversial experiments in the 1990s at Duke University by Mary Eubanks seemed to show that two species of grass can crossbreed into fertile offspring that form a new, distinct species which apparently once existed before as the earliest form of corn which is now extinct in the wild. Eubanks later summarized her findings on corn in the book Corn in Clay and founded a new high-tech startup called SunDance Genetics to commercialize the “new” species of corn she had “re-evolved”.